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Gas oil ratio question

Started by SHADOW, December 27, 2010, 10:12:38 AM

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SHADOW

At Christmas eve,I was talking with my father in law
and he say to only use 1:40 ratio in my ms260.

But Stihl owner manual say to use 1:50 Stihl oil ratio
for my saw.

What are you using with your Stihl?

Why?

Thanks
STIHL.

Warbird

I have always used factory recommendations for my 2 Stihls and have had no problems.

lumberjack48

When a saw is still under warranty , absolutely run the mixture they call for, because this is the first thing they check is the gas, if you have trouble. A Stihl dealer was a friend so he gave me heads up how the warranty worked.
After warranty he recommended me to run 32:1 because he new how hard i ran my saws, I had a 038 Mag and a 044 Mag for 8 yrs on the job, these saws impressed me.  I used a 034S for a felling saw, i would tip up to 400 trees a day with it, in clear cut Aspen, that little saw impressed me every day, I'm pretty hard to impress. Pound for pound the fastest saw i ever had was a Lombard Lighting 3, boy she was hard on the ears, it looked like a XL12 Homelite.

Happy New Year
Third generation logger, owner operator, 30 yrs felling experience with pole skidder. I got my neck broke back in 89, left me a quad. The wife kept the job going up to 96.

Al_Smith

Quote from: lumberjack48 on December 27, 2010, 12:14:43 PM
 Pound for pound the fastest saw i ever had was a Lombard Lighting 3, boy she was hard on the ears, it looked like a XL12 Homelite.

Happy New Year
For all intents it was a Homey Xl-12 just larger .According to a local dealer who at one time sold Homelites that saw engine ,Al 42 series was designed by the same engineer who did the Xl-12 . Fact is If I'm not mistaken there might be a larger version also using the same time tested design .Might have been sold by Remington .

BTW if anyone owns a Comango,Lighting,Lighting II or III or super Comango they are known seal leakers .Good old cutters .I have two operational and three in parts boxes with scalded cylinders because someone cooked them,not I though .

lumberjack48

Thanks for the info Al, very interesting , i seen it break the start rope when i shout it off. It had more compression then any saw i have ran, it would just about tear your fingers off. I had to replace the starter rope once or twice a day, you had to seek up on it to start it. 
Third generation logger, owner operator, 30 yrs felling experience with pole skidder. I got my neck broke back in 89, left me a quad. The wife kept the job going up to 96.

Al_Smith

I don't think they are an excessively high compression engine although they do have a lot of power for 4.2 cubic inchs . You have to keep in mind though that that engine had a 35 degree advance of spark so more than likely it would bite you at least on occasion .For what it's worth though I've had worse finger pullers .

Something I might add though on that series since it's kind of a side track at the moment .The newer models had a screwed up auto oiler that like some of the McCullochs would leak bar oil into the crankcase .Made them smoke like they were burning soft coal .Now the problem with that was not the fact if they would run because they would  but it masked a bad seal . People would get annoyed and block off the crankcase tube and just use the thumb oiler .What would happen then is they would lean out and cook the cylinder  because of the leaky seal .

In thinking this over knowing with what I know  today that is most likely why Lombard recommended them to be ran on 20 to 1 oil ratio .At that time period most other brands were at 32 or 40 to 1 .That extra little shot of oil would have most likely saved them although better seals would have been a better plan .

SPIKER

It has/had been recommended to me that you run the lowest ratio based on the engine MFG & oil MFG you are using.   If you read up on the oil brand you are using it should give you a mix ratio based on that oils manufacture.   They design the oil to properly lube the engine when mixed per the oils instructions. 

SO if the engine mfg says 40:1 and the oil manufacture says mix it 32:1 then I mix it 32:1.   If the engine is 40:1 and the oil is 50:1 then I mix it 40:1.   I have NEVER had an issue with any of my 2 cycle engines this way even power always seems very good.

Mark
I'm looking for help all the shrinks have given up on me :o

JohnG28

When I mix fuel for my Stihl I use the pre measured bottles but put a little less fuel than is recommended.  For a bottle made to mix one gallon I go with around 9/10 gallon.  This makes around 45 to 1 and accounts for any small amount left in the bottle.  I also run a fuel stabilizer mixed with the fuel.
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

John Mc

Shadow -

If you use a good quality oil and keep your engine tuned properly, 50:1 ratio will work just fine. The 40:1 ratio (or 32:1 or whatever) that your father-in-law used in his younger days was likely driven by the limits of the oil they were working with back then. Oil has improved a lot over the last couple of decades. I run 50:1 in all my chainsaws. I also run 50:1 in my weed whacker (which calls for 32:1) and used to run 50:1 in a leaf blower I had (called for 40:1). I never had any lubrication-related problems with any of them. I did have to re-adjust the carb fuel mixture settings when I switched from running the factory recommended oil ratios to 50:1.

John Mc
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

smalldog

Just remember the more oil you put in the mix, the leaner the fuel/air ratio is. Your carb jets flow only so much mix, so if you have more oil, you have less fuel. So, if you have one of these newer, fuel efficient saws that are running quite lean anyways, then you mix at 32:1 instead of 50:1, you just made your fuel/air ratio 35% leaner. You may think you are saving your engine from seizing with more oil, but, in fact it may be worse unless you adjust your carb richer.
Hang in there body...just a little further to go.

Al_Smith

 ??? I'd like to know where that line of thinking or thought pattern originated ?

Rich or lean regarding the saw is merely refering to the air and fuel ratio and has nothing to do with the oil ratio .The oil leaves behind a residue of microscopic particles which lube the cylinder bearing etc .Without it the engine would cease to run after a few seconds .

If one would adhere to that then the old saws and outboards would never have lasted as long being operated on 16 to one fuel/oil ratios .Fact being there are literally thousand of those old relics which still run as good today as they did 50 years ago ,heavy oil or not .

Now I'm not suggesting by any means to operate a modern saw with modern oils mixed at 16 to one .Unless you are fogging for mosquitos but it certainly won't cause one to sieze unless it were poorly tuned .Then again any poorly tuned saw stands a chance to become  door stop if tuned too lean .

chucker

Quote from: Al_Smith on January 17, 2011, 09:10:59 AM
??? I'd like to know where that line of thinking or thought pattern originated ?

Rich or lean regarding the saw is merely refering to the air and fuel ratio and has nothing to do with the oil ratio .The oil leaves behind a residue of microscopic particles which lube the cylinder bearing etc .Without it the engine would cease to run after a few seconds .

If one would adhere to that then the old saws and outboards would never have lasted as long being operated on 16 to one fuel/oil ratios .Fact being there are literally thousand of those old relics which still run as good today as they did 50 years ago ,heavy oil or not .

Now I'm not suggesting by any means to operate a modern saw with modern oils mixed at 16 to one .Unless you are fogging for mosquitos but it certainly won't cause one to sieze unless it were poorly tuned .Then again any poorly tuned saw stands a chance to become  door stop if tuned too lean .
i like your way of thinking!! perhaps this is the reason why all my "old junkers" are still in action?
respect nature ! and she will produce for you !!  jonsered 625 670  2159 2171/28"  efco 147 husky 390xp/28" .375... 455r/auto tune 18" .58 gauge

smalldog

I'm NOT saying that more oil is bad or that it causes damage. I'm saying that if you replace gasoline molecules with oil molecules going through a fixed jet size, you ARE leaning the fuel/air mixture. If you want to send more oil through that carburetor jet, fine, just allow for the change and increase the jet size to keep the same amount of fuel. Yes, the old 2-strokes ran high amounts of oil in their fuel, but, look at the jet sizes. They had larger jets to make sure they had an sufficient amount of fuel also.
Hang in there body...just a little further to go.

Al_Smith

Well firstly I'm casting espersions nor picking on anyone .

The first time I ever heard this mentioned was a certain on line personality who was so anal about things he would invaribley argue that for instance 3/8" pitch chain was not it fact truely 3/8" .The same with the oil mix ratios saying 40 to one was actualy some other ratio and argue forever he was correct and the rest of the world was wrong .I suppose he might have mixed his fuel under laboratory conditions perhaps . ::)

Now I could care less  nor give a hill of beans about anyones favorite oil nor how they mix or in what ratio , not my saws .I have however seen way more saws get a fried top end from a lean carb setting than from running a rich fuel/oil ratio .It may sound neat and bad to the bone running like the wind out of the wood but unfortunatley given enough time the saw will clam up and never make another peep.The sounds of silence .Then if large enough, a boat anchor, smaller a door stop . :(

Al_Smith

Quote from: smalldog on January 17, 2011, 10:31:24 AM
I'm NOT saying that more oil is bad or that it causes damage. I'm saying that if you replace gasoline molecules with oil molecules going through a fixed jet size, 
They aren't fixed unless they are smaller less expensive home owner type saws in most cases .That's what the needle valves are for,to adjust the mixture .

Now granted from time to time some saw manufactures had the bright idea to use fixed jets but that had more to do with stopping warentee work than any thing else .As a rule they didn't run worth a hoot though .

It makes sense that less oil in the mix would burn a little hotter the same as a lean mixture would .However going to the absolute extremes just for debates sake it would be unwise to lessen the ratio to perhaps 80 to one in the interest of providing more gasoline than oil .That would be just another boat anchor in waiting .Not good .

smalldog

I was just trying to bring up what I learned at Suzuki and Yamaha service tech schools. Because I had customers that depended on me to help them with their problems, I would listen in class and read the service bulletins. I had people that would take a engine made for 40:1 and switch to 100:1 amsoil and wonder why it's running rich. Or the person that has a machine made for 50:1 that runs 20:1 and cooks the top end from heat. Make sure you rejet if your changing your premix ratio. 2-stroke oil in your fuel lowers your octane rating also. That's why they say to run higher octane fuels. So you get the customer that has a MS460 with a dual port muffler cover(which will lean it), and is running regular low octane fuel mixed at 32:1(more oil=less fuel), and wonders why it has problems. A MS460 comes with about a .68mm main jet. If you mix at 32:1, that is a 1.125% increase in oil volume going through the jet which means 1 jet size increase. Some people will wrongly blame the oil for damage, when in fact the ratio and jetting was the cause.
Hang in there body...just a little further to go.

John Mc

Samlldog -

I know little about small engines. However, I can follow what you are saying, and see the logic in it. If the carb is set to allow a certain amount of gas/oil fuel to mix with the air, and you put more oil in your mix, you have less gas in that amount of fuel mix the carb is metering in. Less gas = leaner burn (depending on what is happening to the oil??) I would also guess that if the viscosity of the fuel mix was changed significantly by the extra oil, that might allow less of the fuel mixture into the carb.

I wonder how significant the change is? If I tuned my saw using non-ethanol gas, then switched to E10 gas, I found I needed to tweak the mixture setting a bit richer to get back to the same place (makes sense, since ethanol is an oxygenated fuel). It was pretty subtle however - and may have even been in my mind, since I'm no ace at tuning saws at this point.

My question is, woudl you really need to re-jet the saw? Can't you just adjust the mixture a tad to compensate?
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

smalldog

Yes, you can adjust the H screw but you will notice the mid range lean like many of the new EPA saws have. You know what I mean...when you touch the wood only running half throttle and it seems the saw has no power unless your running full throttle. If you rejet, you gain that midrange torque.
Hang in there body...just a little further to go.

Al_Smith

Hmm,well first of all it's apples and oranges .A rich burner two stroker motorcycle has usually had oil injection or the few I paid attention to have had for decades . Of course being an old Harley man I gave them little heed . 8)

Generally speaking a saw has two running conditions ,wide open ,let -er-rip or idle .All mid range does is get you to top speed .BTW a duel port or in fact any muffler modifications are design to allow the saw engine to breathe better .More air,more fuel but of course the carb needs to be reset , elementry . Back to that  adjustable jet thing . ;) Try as I might I can't get through my 2 inch thick scull why anybody would run a saw at half throttle for very long  ??? Unless you were limbing with an 084 or something which I'll guarantee you won't do for very long .Cruel and unusual punishment .

smalldog

Yes, 100:1 is not much oil. I've seen crank bearings and lower rod bearings go bad
and wrist pin scuffing on engines running 100:1 mix.
Hang in there body...just a little further to go.

smalldog

Suzuki came out with a service bulletin on ethanol fuel used in premix back in the 80's. It said the problem with ethanol is it will absorb moisture and in turn, force the oil out of the premix. So, we tried it. We mixed a 40:1 premix using 10% gasahol(we tested it) in a glass container. We slowly added water to the mixture(several drops at a time). It was amazing how much water could be absorbed instead of settling on the bottom. Before long you could see the oil forming into small droplets in the mix.
Hang in there body...just a little further to go.

smalldog

OK AL, NONE of the Honda CR's, Kawasaki KX's, Yamaha YZ's, or Suzuki RM's EVER had oil injection. Neither did the racing 2-stroke ATV's(like my LT250R) or the Kawasaki Jet Skis I worked on. Or the all the early snowmobiles and ultrlights I've had.

I'm not saying you HAVE to have a nice mid range, but, it sure is nice. :)
Hang in there body...just a little further to go.

Al_Smith

 :D I'm having flashbacks I think or I've traveled this road before with  about the same success rate I'm probabley going to have with this discussion .

We should take a survey of two things .First just how many people run a saw for an extended  period of time at half throttle and secondly who would suggest that operating a saw with more oil per gallon mix as opposed to less would suggest that more would cause the saw any harm regarding a tendency to cease .

I mean for heavens sake that's about like saying it's better to straight gas them .We all know that won't work---or do we . :)

smalldog

 I'm having flashbacks I think or I've traveled this road before with  about the same success rate I'm probabley going to have with this discussion .

Ditto

All I'm saying is the premix ratio affects jetting. If you want, Google "premix affects jetting" and read for your self.

I never said less oil is better. I did say that if you have a newer EPA saw that is quite lean to begin with, increasing the oil in your premix WILL lean it out further. Just adjust your carb for the new mix.

I NEVER said I run my saw for EXTENDED periods at part throttle. I DO enjoy a saw that has a non EPA midrange (slightly richer) that will actually cut wood at part throttle. That enables me to start a cut at part throttle, then roll into full throttle.(remember the old saws?) Some of these new EPA saws are so lean at part throttle, the HAVE TO be full throttle at the very start of the cut.
Hang in there body...just a little further to go.

Al_Smith

Quote from: smalldog on January 17, 2011, 02:40:58 PM
   .

I That enables me to start a cut at part throttle, then roll into full throttle.(remember the old saws?) Some of these new EPA saws are so lean at part throttle, the HAVE TO be full throttle at the very start of the cut.
:D :D Remember who you are talking to .I remember the "old " saws when they were new saws .Fact is I ran the Mac 250 about the first year they were on the market if that tells you any thing .

That aside the only" new " saws I have are the pair of Stihl 200T's .I doubt they are EPA  compliant .Especially after I got through tweeking them . 8)

Plus the fact I'm somewhat of an outlaw sawman when it comes to edicts of the EPA .Chances are if I do ever get one of those so called EPA saws its' chances of staying that way are somewhere between slim and none .

Joking aside I've never ran much less fiddled with one of those things .As I type though residing in my shed are several brand new Stihls that belong to a trimmer bud of mine .Once he gets tired of whimpy saws chances  are great the EPA wouldn't much approve of those either .Now keep this on the QT because I don't want the chainsaw police knocking at my door . ;)

weimedog

Still 32:1 after all these years....since I always run 32:1, and I always stay on top of the tuning I never have to "re-tune" because i have no intention to changing until I see a reason to do so. One thing I can say...theoretically..a racing two stroke might generate slightly less "flash" peak HP with the heavier oil mixes, but at the end of a race they will have lost less than those pushing the edge in mixtures with less oil. AND I can tell you they last longer over a season than those with less oil in the fuel. Part of the reason earlier synthetics wanted to be a 50:1 was first a marketing deal and second, they didn't burn as clean as the products they were replacing and would make a mess of the exhaust...now they have improved to the point they burn cleaner than the old non synthetics as well as out perform them in higher heat & shear situations. My feeling is the power you might loss with the more oil is gained thru less losses due to heat and friction over the period of a race. Wish there was numbers to back that up...but my seat of the pants during the races when I was doing that and my eyes evaluating tear downs have pushed me to ..not change from the 32:1....in motorcycles and now in saws.
Husqvarna 365sp/372xpw Blend, Jonsered 2171 51.4mm XPW build,562xp HTSS, 560 HTSS, 272XP, 61/272XP, 555, 257, 242, 238, Homelite S-XL 925, XP-1020A, Super XL (Dad's saw); Jonsered 2094, Three 920's, CS-2172, Solo 603; 3 Huztl MS660's (2 54mm and 1 56mm)

Al_Smith

Once again I'm kind of like Walter in the fact I see no reason to change either .Evidently most of the hotsaw guys don't either because they mostly run higher grade oils at----32 to 1 -----  ;D I figure if it's good enough for a 5,000 dollar hotsaw it's good enough for me .

stump farmer

I've always run 40:1 thinking that I've built in a little buffer for safety due to the elevation differences I work at: sea level to 10K+. Smalldog's point is making me re-think that, I do follow what you're saying with the less fuel=leaner due to more oil in the mix. And yes my saws do feel lean at low elevations. Good info, thanks.

Al_Smith

If you tuned them for 10,000 they would be lean a couple thousand lower .Conversely tuned at sea level then going to 10 thou they'd likely blow black smoke .

stump farmer

They get tuned around 2k and I've been limiting the high rpm to 12500 (stihl 460) in the hope of again having a buffer. Trading some performance for reliability I hope. I'm looking for a setting that will work well enough for all elevations. I won't allow anyone on the crew to field adjust the saws as it usually results in a seized saw. Those little orange handled screwdrivers are locked away. This has been working OK, but I'm always looking for something better. Never thought that using more oil could lean the saw.

Al_Smith

 :D It doesn't lean the saw .That's taking one persons opinion and discounting 100 others .Besides 40 to one is an accepted ratio .

Well then ,take junker of a saw and run it at 80 to one and document exactly how that works out for you . :)


stump farmer

Realize it's an opinion, but an interesting one at that.

Al_Smith

Okay ,let's look at it in a different perspective .When you run any engine with too much air in the mix it runs lean .Lean ratios of fuel  to air  burn faster which also equates to hotter .Now because some type of oil is required in the fuel mixture for two cycles it would effectively lower the heat generted by the combustion of the fuel merely because it lowers the burn rate .Plus the fact it gives lubrication to the vital components of the engine ,most important .

So that said that fuel and oil ratio will remain the same no matter if the saw is at the top of Pikes Peak or in Virginia Beach Va at sea level .The only thing that needs changed is the adjustable carb jets to effectively change the fuel to air ratio .

Now a modern automobile does this all by itself using the ECM or engine control model but a chainsaw isn't quit that smart yet,you have to adjust them .

Oh alas ,I'm fighting a loosing battle .

John Mc

Quote from: stump farmer on January 19, 2011, 01:53:42 PM
Example: a 40:1 mix will have twice the fuel in the air/fuel mix as will a 20:1 mix because the extra oil is not taken into account for air/fuel mix calculations.

No. 40:1 will have slightly more fuel, but no where near twice the fuel. The % fuel in 40:1 is 40/41=97.6% gas. In a 20:1 mix, it's 20/21=95.2% gas. A pretty small variation, which might just be overshadowed by altitude or temperature variation. The difference in % of Gas between 40:1 and 50:1 is s

QuoteAnother question: how much does outside air temperature affect the air/fuel ratio? At 120 degrees the air should be thinner that at 40 degrees. The colder air is denser which will richen up the mixture.

Denser, colder air will make the mixture leaner, not richer (more air per unit volume).

If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

stump farmer

Thanks for setting me straight. That post was all wrong.  :-[

John Mc

No problem. I get it backwards myself half the time.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

smalldog

Opinion of one??? I take it you didn't search the subject then.  Whatever.......
Hang in there body...just a little further to go.

SPIKER

There were a good number of inject-able oil engines back in the late '70's when they were coming out.   I have a '77 Kawasaki 440 snowmobile setting out back with it on , though I mix it rather than depend on the injection function properly.   Also had a RD350 Yamaha street bike circa 84 that was I think a '76 vintage bike.  That was a ride pretty much the first crock rocket ;)   Bright orange with black stripes.

Like others mentioned Mix is less important than the Oil brand recommendations from what I have read learned through past.  Oil in the mix is only partly burned so it displaces gas and a slight lean condition could develop but at such a low rate that a 1/4 turn on the A.F. screw or dirty filter is a bigger problem than the oil change from 40:1 to 50:1 will make.   The rich oil mix will also raise the octane rating of the fuel slightly as it lowers temp & ignition point of the fuel during high speed running.   Some types of oil also burn less than others and can foul exhaust system and carbon up or foul plugs which also increases compression ratio on small engines that are often in the 13~14:1 compression already slight build up can effect pre-ignition detonation which is also where overheating & melt downs can happen when running low octane blends.   Toss in the 10% or more ethanol in most fuels today and you can really bugger up a small 2 cycle engine which is why there is some legal pressures to NOT push the E15/E85 stuff the EPA has mandated for 08 & up cars.

Mark
I'm looking for help all the shrinks have given up on me :o

tyb525

All 2-stroke engines require oil. Oil is their lifeblood, because without it, they wouldn't run for long.

Historically, running a mix richer in oil, such as 30:1, has been successful since day one.

Sure, technically 30:1 will be "leaner" than 80:1. BUT that does NOT mean it is getting less oil! Failure from running lean is due to heat and lack of lubrication. The oil has the ability to cool AND lubricate.

SO, running a mix of 80:1 simply means you must burn more mix in order to get equal lubrication. You will use the same amount of gas, but now where is the lubrication (oil)? It is reduced.

Is reduced lubrication ever a good thing in an engine of any sort? Would you run 0w20 oil in your diesel, or mix your lawnmower's engine oil 50% gas and 50% engine oil to thin it out in order to use less oil?

Sure, they might run okay for a little while, but what about long term? What about when the engine really gets pushed, or you forget to change the oil for awhile? Since you were really toeing the line of proper lubrication from the start, what now?

Just because you can run your saw with 80:1, why risk it? Have you done rigorous tests with all saws to make sure they can stand up to that? You're really pushing the envelope running mix with that little amount of oil.

At what ratio is there too little oil? When you reach straight gas?
LT10G10, Stihl 038 Magnum, many woodworking tools. Currently a farm service applicator, trying to find time to saw!

Al_Smith

Quote from: tyb525 on January 19, 2011, 11:37:33 PM
Sure, technically 30:1 will be "leaner" than 80:1. BUT that does NOT mean it is getting less oil! Failure from running lean is due to heat and lack of lubrication. The oil has the ability to cool AND lubricate.

  At what ratio is there too little oil? When you reach straight gas?

Thank you ,that's the point I was trying to make all along but with little success .

weimedog

And to add a little fuel to the fire..when you tune your saw, you are basically tuning the burnable fuel to air ratio...not the oil air ratio. And while you may have to tweak from one mixture to the next assuming someone randomly changed the oil gas ratio's I have found the difference between 40:1 and 32:1 to be small enough that when I run short on fuel, my friends 40:1 mix work fine..usually without the need to change anything...it has happened..not often.

I guess another way to look at it is you tune with your hi and low speed adjustments until you get the the right volume of fuel...the oil goes along for the ride. And yes those screws might be turned out a little more to accommodate the additional volume of oil. But its a bit backward to think the oil is leaning out the mixture...and as was said in many ways before, there are lots of additional benefits to having a bit more oil than less....still 32:1 after all these years...and everytime I tear a saw or motorcycle down (Like last week's Jonsered 820) that has time on it..the more empirical evidence is telling me not to change...:)
Husqvarna 365sp/372xpw Blend, Jonsered 2171 51.4mm XPW build,562xp HTSS, 560 HTSS, 272XP, 61/272XP, 555, 257, 242, 238, Homelite S-XL 925, XP-1020A, Super XL (Dad's saw); Jonsered 2094, Three 920's, CS-2172, Solo 603; 3 Huztl MS660's (2 54mm and 1 56mm)

clww

I run 32:1.
No discussion :D :D
Many Stihl Saws-16"-60"
"Go Ask The Other Master Chief"
18-Wheeler Driver

Just Me

Quote from: Al_Smith on January 17, 2011, 01:07:51 PM
Try as I might I can't get through my 2 inch thick scull why anybody would run a saw at half throttle for very long  ???

Log home work. I have a couple of Husky 142's with crosscut and rip chains that I use, and there are many times I have to be cautious not to make a costly mistake, so I run mid throttle.

That being said, I run synthetic, have since the 70's, but at 32-1. I have those two saws tuned to run well in the middle, and I do have to change plugs more often, but they serve me well.

I am a firm believer in synthetics. We had a smashed radiator on our race truck at Crandon, finished the race and the gauge was pegged the last two laps, gauge went to 350 degrees but we have no idea how hot it actually was, just over 350. At the finish line it was so hot it burst into flames when it stopped, motor siezed immediately. After it cooled down, the motor restarted and was able to finish the race the next day, although a tad down on power. When torn down there was some ring damage and scuffing of the cylinders but the rod and main bearings were fine. Amazing.

I use it in everything that is expected to work hard, from cement mixer to tractor.

Someone mentioned a Yamaha RD 350. I had one of those for years set up for road racing just to play with with a full engine build. Bad fast! It would beat my 1000 Kawasaki up to its 120 mph top end. I can't imagine how Enderle won Daytona with one though as my hand were so numb after 10 miles that I couldn't feel the bars. It was fun, but the local constabulary told me the next time they caught me on the street I was going to jail. Had to let it go..... :(

smalldog

This is just too funny!

This is what I said 17 posts ago: All I'm saying is the premix ratio affects jetting. If you want, Google "premix affects jetting" and read for your self.

I never said less oil is better. I did say that if you have a newer EPA saw that is quite lean to begin with, increasing the oil in your premix WILL lean it out further. Just adjust your carb for the new mix.

Now, I never stated what ratio I run, I never said that I think people should run a specific ratio.

I have converted many sleds, cycles, and atv's from oil injection to premix. Many of them were for people that raced. The newer ones were Yamaha RZ350 cycles and the 350 Banshee ATV's. In those cases, going from zero premix (injection)and going to say a 32:1 ratio, will have to increase the size of the carb jets to allow for the volume of oil that is now flowing through them.

I don't care what brand oil, at what ratio or what brand saws you run, my only point is: if you change the percent of oil going through the jets of your carb, you are also changing the amount of gas going through.

Yes, the Yamaha RD bikes were good bikes. I've worked on many on my own and at the dealer. I personally had  '70,'72,'73 Kawasaki 500 triples and a nasty '72 H2 750 triple with milled heads and chambers.

Hang in there body...just a little further to go.

smalldog

Yes, if you have a older saw you will have nice big carb jets and fuel screws. Some modern EPA saws (most are non pro saws) are coming with either restricted adjustable screws or no screws at all. Many have pressed in jets in the carbs. I all ready went through this back in the 1980's and 1990's with motorcycles, snowmobiles, and ATV's at the dealer. This is going to get much worse before it gets better. Fuel injection helped everything from auto's to snowmobiles as far as the lean EPA standards went. What will happen with chainsaws? Fuel injection or 4-strokes? Definitely more weight.
Hang in there body...just a little further to go.

screwman

Quote from: smalldog on January 20, 2011, 09:28:37 AM
Yes, the Yamaha RD bikes were good bikes. I've worked on many on my own and at the dealer. I personally had  '70,'72,'73 Kawasaki 500 triples and a nasty '72 H2 750 triple with milled heads and chambers

Wow, man, those things were downright scary.

weimedog

Quote from: smalldog on January 20, 2011, 09:47:58 AM
Yes, if you have a older saw you will have nice big carb jets and fuel screws. Some modern EPA saws (most are non pro saws) are coming with either restricted adjustable screws or no screws at all. Many have pressed in jets in the carbs. I all ready went through this back in the 1980's and 1990's with motorcycles, snowmobiles, and ATV's at the dealer. This is going to get much worse before it gets better. Fuel injection helped everything from auto's to snowmobiles as far as the lean EPA standards went. What will happen with chainsaws? Fuel injection or 4-strokes? Definitely more weight.

I'm betting on battery less fuel injection systems like on the new four stroke motocrossers. That with some level of ignition & fuel curve control as on those race bikes as well. A whole new area for those who like to tinker to play...and before folks cry about the concept...look at model railroading, race bikes, race quads and a whole host of other area's where the interface of cyber tech and the control systems of mechanical systems generated entire new places to hack around. I'm looking forward to it and I really don't think weight will be as much of an issue as the technology evolves...anymore than it is with the two wheeled world.
Husqvarna 365sp/372xpw Blend, Jonsered 2171 51.4mm XPW build,562xp HTSS, 560 HTSS, 272XP, 61/272XP, 555, 257, 242, 238, Homelite S-XL 925, XP-1020A, Super XL (Dad's saw); Jonsered 2094, Three 920's, CS-2172, Solo 603; 3 Huztl MS660's (2 54mm and 1 56mm)

Just Me

Quote from: weimedog on January 20, 2011, 12:56:23 PM
Quote from: smalldog on January 20, 2011, 09:47:58 AM
Yes, if you have a older saw you will have nice big carb jets and fuel screws. Some modern EPA saws (most are non pro saws) are coming with either restricted adjustable screws or no screws at all. Many have pressed in jets in the carbs. I all ready went through this back in the 1980's and 1990's with motorcycles, snowmobiles, and ATV's at the dealer. This is going to get much worse before it gets better. Fuel injection helped everything from auto's to snowmobiles as far as the lean EPA standards went. What will happen with chainsaws? Fuel injection or 4-strokes? Definitely more weight.

I'm betting on battery less fuel injection systems like on the new four stroke motocrossers. That with some level of ignition & fuel curve control as on those race bikes as well. A whole new area for those who like to tinker to play...and before folks cry about the concept...look at model railroading, race bikes, race quads and a whole host of other area's where the interface of cyber tech and the control systems of mechanical systems generated entire new places to hack around. I'm looking forward to it and I really don't think weight will be as much of an issue as the technology evolves...anymore than it is with the two wheeled world.

I have to agree. In 1973 I had a 125 Suzuki TM 125 2 stroke motocrosser that weighed 212 dry. It had about 7 inches of travel and that was about all it had, Fast in its day, but not even a good play bike by todays standards. After that bike they started picking up weight as they picked up travel.

Fast forward to 2004, I bought a KTM EXC 450. Had a Bad 450, 12.5 inches of very controllable/adjustable travel, brakes that worked, did I mention a 4 stroke, six speed tranny, and it had lights and electric start. Weighed in at 252 pounds, but it felt ever so much lighter that the TM. KTM has a two stroke 250 with electric start at just over 220, and a whole lot more bike in that 8 pound difference.

The EPA is up our Heineys on every front, so it is only a matter of time before the mandate the use of FI, or make emission restrictions that can only be passed by a FI motor. Not necessarily a bad thing, but the cost of saws will go up.

I cant make up my mind if I should buy a 345XP or a 357XP. Maybe I should buy both, then I'll be set till I'm old and gray. Oh wait, I'm already gray........

Al_Smith

Quote from: smalldog on January 20, 2011, 09:47:58 AM
Yes, if you have a older saw you will have nice big carb jets and fuel screws. Some modern EPA saws (most are non pro saws) are coming with either restricted adjustable screws or no screws at all. 
Okay maybe for consumer saws and those not really adept at saw tuning .However keep in mind that some of us do not fit in that catagory .Besides that, they  as they might  still haven't figured out how to make a carb we can't fiddle with .If they think they can,bring it on .If we can't tweek it we'll just change it out to one we can and keep the mix ratio we already have . 8)

.

John Mc

Quote from: Just Me on January 20, 2011, 07:18:46 PM
I cant make up my mind if I should buy a 345XP or a 357XP. Maybe I should buy both, then I'll be set till I'm old and gray. Oh wait, I'm already gray........

Did you mean the 346XP?

BTW... Husky has a replacement for the 357XP in the works... The 560 or 562XP. From what I've read here, it sounds like quite a saw.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

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