Author Topic: Any one blow up their Dolmar PS5100 yet? (Read 9080 times)

Max sawdust · « **on:** October 17, 2008, 11:04:39 am »

Hi all,
Last November I bought a Dolmar PS5100. Worked great and fairly happy with the saw, doing small logging jobs, firewood and notching rafters for log construction. This fall I tried it for ripping the lateral in log construction and it stopped working. Complete enine failure, apparently lower crank shaft failed. (Saw was sent back to Germany for inspection, actual failure not known yet.)

Luckly I have a great local dealer, and got a new saw for free under warranty.

Just an FYI and interested if anyone else has had failures.

Max

Al_Smith · « **Reply #1 on:** October 17, 2008, 12:11:35 pm »

I don't know ,never heard much about them giving up the ghost .

However those little handy dandy saws that run like a scalded ape don't do well on long extended cuts running like crazy on 50 to one mix . About like hitching a throughbred to a plow when a Clydesdale would do better .

ladylake · « **Reply #2 on:** October 19, 2008, 04:53:50 am »

Most new saws are adjusted a little too lean these days thanks to the EPA. Factory RPM spec are a little lean and if you get gas with ethonal it just gets worse. If using a tack back off the RPM some, for sure when working the snot out a saw doing long cuts. And they'll have better torque with a little more fuel. Steve

Al_Smith · « **Reply #3 on:** October 19, 2008, 05:46:18 am »

Good point about having them set up a tad lean . I suppose it's not my call but some folks just think they have to running right on the edge . I'm not suggesting this is the cause for failure ,could be or could be something else .Who knows it's after the fact .

Madsens had a good little audio on how a saw should sound tuned in right ,pretty helpfull . Try it some time ,you might be surprised .It my sound a little sluggish but that "4 cycle " gurgle turns into power when the engine really gets under load .

I once watched a hotsaw in southern Ohio that surprised the dickens out of me as it was being warmed up prior to the event .Sounded extremely rich I thought but then I know the builder and he has forgotten more than I will ever likely know about saw engines . Well ,just as I said ,when that thing hit the wood and that pipe kicked in it was all power .Same deal on a work saw to a certain extent .

SawTroll · « **Reply #4 on:** October 21, 2008, 09:24:33 am »

Quote from: Al_Smith on October 19, 2008, 05:46:18 am

Good point about having them set up a tad lean . I suppose it's not my call but some folks just think they have to running right on the edge . I'm not suggesting this is the cause for failure ,could be or could be something else .Who knows it's after the fact .

Madsens had a good little audio on how a saw should sound tuned in right ,pretty helpfull . Try it some time ,you might be surprised .It my sound a little sluggish but that "4 cycle " gurgle turns into power when the engine really gets under load .

I once watched a hotsaw in southern Ohio that surprised the dickens out of me as it was being warmed up prior to the event .Sounded extremely rich I thought but then I know the builder and he has forgotten more than I will ever likely know about saw engines . Well ,just as I said ,when that thing hit the wood and that pipe kicked in it was all power .Same deal on a work saw to a certain extent .

Was that saw ran a lot on less than full throttle when making notches etc?

Max sawdust · « **Reply #5 on:** October 21, 2008, 07:09:38 pm »

Less than full throttle question...

Yes 50/50 Wide open and 1/4 throttle...

max

SawTroll · « **Reply #6 on:** October 22, 2008, 10:21:33 am »

Quote from: Max sawdust on October 21, 2008, 07:09:38 pm

Less than full throttle question...

Yes 50/50 Wide open and 1/4 throttle...

max

Running on less than full throttle makes it run lean, as most saws have no "midway" needle.

Some saws are more woulnerable than others, as far as I know.

Al_Smith · « **Reply #7 on:** October 22, 2008, 11:37:54 am »

Well that's a point to ponder .Most if not all those little saws can be ran all ahead flank without over reving them .

Of course being an "old schooler " I run them on 32 to one and never cooked a saw in my life . Now 10,000 people will chime in and say I'm so old fashion I should be riding in a horse and buggy but hey ,I never ruined a saw engine .

Enough of that ,sorry about the little saw .May it RIP .

Rancher · « **Reply #8 on:** October 22, 2008, 07:56:03 pm »

I run mine a little rich on the oil. I have to run lean since there is less oxygen up here at 10,000 ft.

cheyenne · « **Reply #9 on:** October 22, 2008, 08:36:13 pm »

I'm with Al i run all my saws 32 to 1 never blown one yet. Knock Knock Knock on wooden head....Cheyenne

Cut4fun · « **Reply #10 on:** October 22, 2008, 08:46:33 pm »

There was some kind of recall on the 5100S. It had to do with the intakes and leaking. There was a updated part to replace the old one. Thats all I can remember on this one sorry

.

Al_Smith · « **Reply #11 on:** October 23, 2008, 12:35:10 am »

Quote from: Rancher on October 22, 2008, 07:56:03 pm

I run mine a little rich on the oil. I have to run lean since there is less oxygen up here at 10,000 ft.

Ah yes ,the Colorado mountains . Reminds me of the time,late 70's early 80's on a deer hunt west of Vail ,Wolcott[white mountains ] . We always took two saws to cut camp wood . A little Pioneer and my s-25 Poulan .We were about 10,000 feet and the danged things would boil the fuel in the gas tank . Other than that they ran fine . Of course we had to lean them up a tad .

I haven't seen anything like it ,before or since .

ladylake · « **Reply #12 on:** October 23, 2008, 04:53:23 am »

They're not running any leaner up high, just less fuel to go along with less air resulting in less power. Same ratio unless they're tuned too lean. Steve

Al_Smith · « **Reply #13 on:** October 23, 2008, 10:35:27 am »

Correct ,of course the fuel oil mix ratio doesn't change just the amount of oxegon to burn the fuel .In addition to retuning the saws in those Colorado mountains we had to retune the Jeeps as well as retard the timing a tad bit at those altitudes .

It wasn't a big deal on the saws as far as power .We were only cutting maybe 8 inch aspen which compaired to Ohio oak is about like cutting balsa .

snowman · « **Reply #14 on:** November 01, 2008, 11:30:50 am »

Quote from: Cut4fun on October 22, 2008, 08:46:33 pm

There was some kind of recall on the 5100S. It had to do with the intakes and leaking. There was a updated part to replace the old one. Thats all I can remember on this one sorry .

My 5100 has been giving me trouble lately, can't seem to keep idle in adjustment. I'll call saw shop today and ask about this recall thing, good info, thanks.

TexasTimbers · « **Reply #15 on:** November 01, 2008, 06:13:01 pm »

snowman, please post the recall info when you find it out.

Mine has been giving me a little trouble with the idle too lately, but I think it is just because it's getting broke in better and I haven't tweaked it in 5 or 6 tanks.

RSteiner · « **Reply #16 on:** November 04, 2008, 11:42:14 am »

Quote from: Al_Smith on October 22, 2008, 11:37:54 am

Well that's a point to ponder .Most if not all those little saws can be ran all ahead flank without over reving them .

Of course being an "old schooler " I run them on 32 to one and never cooked a saw in my life . Now 10,000 people will chime in and say I'm so old fashion I should be riding in a horse and buggy but hey ,I never ruined a saw engine .

Enough of that ,sorry about the little saw .May it RIP .

I purchased a 5100S back in June of this year. I have only run about a dozen tanks of fuel through it so far. Yesterday I cut for 8 hours with it going through 4 tanks of fuel. The saw ran fine the whole time and I would like to do every thing possible to make that continue to happen.

After reading about using a 32 to 1 mix by some of you it got me to thinking. The saw manufacturer says it will run on a 50 to 1 mix. Putting a little more oil in the mix sounds like it can't hurt any thing. The last two gallons of fuel I mixed was at a 40 to 1 ratio. What are the potentail effects at using a little more oil in the fuel, what should one look out for?

Randy

cheyenne · « **Reply #17 on:** November 04, 2008, 07:23:42 pm »

All moving parts need oil. I use to burn 50 to 1 till my dealer who turned out to be a good friend told me to go to 32 to 1 and it has worked out fine. Have not replaced a carb or anything since in the engine. It may be me but my saws sound better, run better & seem to have more power & cut faster they also seem to run cooler, but it could be me or i'm getting old and sitting down more between cuts......Cheyenne

tyb525 · « **Reply #18 on:** November 04, 2008, 09:54:53 pm »

I'm no expert on saws, but when my dad mixed gas he always mixed somewhere around 24 to 32:1. Recently I read in my Stihl manual that it was tuned for 50:1, so I tried that. I didn't like it. It ran too hot for me, and although it seemed to rev a little higher, it didnt seem to have as much torque. I've switched back to 32:1, and am happy with it.

SawTroll · « **Reply #19 on:** November 05, 2008, 04:02:18 am »

Quote from: Cut4fun on October 22, 2008, 08:46:33 pm

There was some kind of recall on the 5100S. It had to do with the intakes and leaking. There was a updated part to replace the old one. Thats all I can remember on this one sorry .

I believe that was about november 2006.

RSteiner · « **Reply #20 on:** November 05, 2008, 06:56:29 am »

You guys have me convinced. I am going to run a little more oil in the mix. This is actually going to save me money. I had been buying my 2 cycle oil in the one gallon mix size containers, a six pack is $10.00. The 2 gallon mix size is $13.00 a six pack, that is twice the amount of oil for only 30% more money.

Using the richer oil mixture does seem to make my saws run cooler and they do have a different / better sound to them.

Randy

ladylake · « **Reply #21 on:** November 05, 2008, 07:09:32 am »

Over here 40 to 1 mixed a little richer. It's the amount of fuel going into the engine that keeps it running cooler, to little it burns hotter and heats up the engine. If adjusted a little to lean they'll get real hot on a long pull like ripping. Steve

SawTroll · « **Reply #22 on:** November 06, 2008, 07:20:02 am »

Quote from: ladylake on November 05, 2008, 07:09:32 am

Over here 40 to 1 mixed a little richer. It's the amount of fuel going into the engine that keeps it running cooler, to little it burns hotter and heats up the engine. If adjusted a little to lean they'll get real hot on a long pull like ripping. Steve

Yes, more oil will make the fuel to air mixture leaner!

RSteiner · « **Reply #23 on:** November 06, 2008, 10:30:38 am »

Yes, more oil will make the fuel to air mixture leaner!

[/quote]

I don't understand how the air to fuel ratio changes when the oil to fuel ratio is changed.

I guess I assumed that the oil and gas together became fuel and that the carb adjustments determined the richness or leanness of the air to fuel ratio. I can understand that the detenation charasteristics of the oil fuel mixture may change a bit as the oil to fuel mix ratio changes.

So, should the carb be readjusted to run a little richer if the oil to fuel mix is changed from 50 to 1 to 40 to 1?

Randy

ladylake · « **Reply #24 on:** November 06, 2008, 10:53:55 am »

More oil will make the mix a little thicker and it won't flow through the jets as good. Nothing wrong with more oil but keep your saw adjusted rich enough to keep from burning it up. Steve

peter nap · « **Reply #25 on:** November 06, 2008, 07:34:58 pm »

Stupid question I guess....but how do you tell when it's adjusted right.
I run 32:1 in both my dolmars, one on an Alaskan and haven't noticed any problems. Don't want any either.

weimedog · « **Reply #26 on:** November 16, 2008, 10:18:21 am »

I'm glad I found this posting...I'm about to buy a 50cc saw and after over analysis came to the conclusion those little Dolmar's (5100's) win the spec sheet wars.

BUT this is primarily for my bride and will be used for cleaning fence/hedge rows, tops and small trees.
She also does a fair amount of carpentry work where part throttle operation is the norm.

I have been talked out of the "Consumer" grade Stihl's over at the other site and boiled down to the Dolmar and new echo CS-530 ....should I reconsider my origional first choice? The Stihl MS250? How about the MS-250 Easy start?

Does the fact that a LOT of the work to be done with this saw selection is, in fact; part throttle and brush work take the Dolamr out of the best choice column?

ladylake · « **Reply #27 on:** November 16, 2008, 12:13:07 pm »

I don't think running it at part throttle burnt it up, if your running part throttle it's on small stuff that might take a second or two to cut. Running lean on long hard pulls is what burns them up. Steve

RSteiner · « **Reply #28 on:** November 17, 2008, 01:11:09 pm »

Does the fact that a LOT of the work to be done with this saw selection is, in fact; part throttle and brush work take the Dolamr out of the best choice column?
[/quote]

I have done a lot of brush clearing with my PS5100. Actually for brush work I want a saw that will rev up quickly and cut the stems rather than pull the saw with a slower moving chain. Last Saturday I helped a farmer friend cut brush and small trees along the edge of one of his fields. I used the Dolmar for about 6 hours. Rarely did the saw run at full throttle for any more than a couple of seconds on the small stuff.

I find it a great saw to use for both brush and larger trees.

Randy

SawTroll · « **Reply #29 on:** November 17, 2008, 07:28:57 pm »

Quote from: RSteiner on November 06, 2008, 10:30:38 am

Quote from: SawTroll on November 06, 2008, 07:20:02 am
Yes, more oil will make the fuel to air mixture leaner!

I don't understand how the air to fuel ratio changes when the oil to fuel ratio is changed.

I guess I assumed that the oil and gas together became fuel and that the carb adjustments determined the richness or leanness of the air to fuel ratio. I can understand that the detenation charasteristics of the oil fuel mixture may change a bit as the oil to fuel mix ratio changes.

So, should the carb be readjusted to run a little richer if the oil to fuel mix is changed from 50 to 1 to 40 to 1?

Randy

Yes, at least in theory, as more oil means less fuel......

TexasTimbers · « **Reply #30 on:** November 27, 2008, 04:38:52 pm »

Mine didn't blow, but this last Sunday my wife and I were in the midst of the largest full scale boxelder harvest we have ever undertaken. We put our saws, our loader and equipment, or chain sharpener even, all of it was pushed to the limit and even abused. Especially our bodies.

Everything held up except the 5100. Have no idea what is the problem but all at once while limbing with it, it died suddenly. I figured what the heck we don;'t have time for precautions and I am not walking through all this brush for another saw I pulled the cord and she purred like a kitten. Pulled the throttle to go at it again and she died dead as heck. Pulled the cord again and let her idle for 30 seconds or so and all was fine. Revved her up again - bogged down this time and died.

Long story short she won't run WOT. Idles fine. later that night back at the shop I palyed with her on the L snd H throttle settings but to no effect. Of course I made sure the filter wasn't clogged, changed the fuel even though I knew that wasn;t it. Can't figure it out.

I'll take her back to Raymond and let him check her out. Seems liek a lot of problems with these 5100s maybe. Hope I don't have to break down and get a 346xp sooner than I was planning. That would absolutely break my heart.

SawTroll · « **Reply #31 on:** November 27, 2008, 05:10:44 pm »

Quote from: TexasTimbers on November 27, 2008, 04:38:52 pm

Mine didn't blow, but this last Sunday my wife and I were in the midst of the largest full scale boxelder harvest we have ever undertaken. We put our saws, our loader and equipment, or chain sharpener even, all of it was pushed to the limit and even abused. Especially our bodies.

Everything held up except the 5100. Have no idea what is the problem but all at once while limbing with it, it died suddenly. I figured what the heck we don;'t have time for precautions and I am not walking through all this brush for another saw I pulled the cord and she purred like a kitten. Pulled the throttle to go at it again and she died dead as heck. Pulled the cord again and let her idle for 30 seconds or so and all was fine. Revved her up again - bogged down this time and died.

Long story short she won't run WOT. Idles fine. later that night back at the shop I palyed with her on the L snd H throttle settings but to no effect. Of course I made sure the filter wasn't clogged, changed the fuel even though I knew that wasn;t it. Can't figure it out.

I'll take her back to Raymond and let him check her out. Seems liek a lot of problems with these 5100s maybe. Hope I don't have to break down and get a 346xp sooner than I was planning. That would absolutely break my heart.

When was that 5100S made?

..there was an important update nov '06 or so....

TexasTimbers · « **Reply #32 on:** November 27, 2008, 07:43:58 pm »

She's an '08 model.

Max sawdust · « **Reply #33 on:** November 27, 2008, 08:00:33 pm »

TT,
Keep me abreast on the resolution with your saw. Not sure when mine was made, but I bought mine that I had a problem with 11-07. Glad I smoked it in 10-08, lower crank and the whole works gone

WARRANTY CLAIM!

Dolmar and my dealer are awesome, new saw in my hands.

Not sure what happened with TT's saw but I liked the saw for felling and limbing, working it hard with 4-6 tanks a many days of the year, before I started ripping laterals with partial and full throttle on log work.

346xp is a nice saw, lasts for a few years with continuous use. (Home owners and guys cutting a couple dozen trees a year for firewood I suspect the saw would last a very long time..) Personally feel the 346xp is a little less troublesome than the 5100. (ie starts hot or cold and idles well at all temps..))
max

snowman · « **Reply #34 on:** November 29, 2008, 08:58:19 am »

Texastimbers said he cleaned filter and changed gas, didn't say which filter though, gas or air. I had same thing happen with my little dolmar and it was a clogged air filter.I have never had a saw refuse to rev from a clogged air filter before, sumpin new for me.I still like this dang little saw but she sure is a finiky thing.

TexasTimbers · « **Reply #35 on:** November 29, 2008, 11:12:13 am »

snowman, I cleaned the air filter but did not pull the gas filter out of the tank (I assume that's where it is). The air filter was about 70% covered so i figured that might be it, but to no avail. I still have not got this saw dropped off to my shop and he is about 4 minutes away.

snowman · « **Reply #36 on:** November 30, 2008, 09:34:12 am »

After my coffee kicked in i gave a Homer Simpson DOOOH! As far as I know you can't clean a fuel filter. Anyway, yes its in fuel tank on end of a rubber hose that you can snag with a bent wire or sometimes just turn saw over and shake. Easy to replace and relatively cheap.

weimedog · « **Reply #37 on:** December 25, 2008, 11:02:32 am »

Sounds like this saw needs a few years of time and upgrades before its ready to compete with Stilhs, Echo's, and PRo Husky's.

Rocky_J · « **Reply #38 on:** December 25, 2008, 12:11:48 pm »

No, it sounds like a carb problem. And Dolmar uses the exact same cheap Zama carbs as Husky and Stihl.

And EVERY problem seems like a big deal until after it's fixed and you (sorta) understand what happened and why. Until then, it's always "oh, the saw is no good, better stick with the pro brands".

TexasTimbers · « **Reply #39 on:** December 26, 2008, 04:22:15 pm »

Raymond wasn't there a couple weeks ago when I picked it up. The tech said he didn't do anything major to it. Didn't write up a ticket but said he didn't know exactly what. I need to stop by again and pay for the new chain he put on it anyway (didn't make a ticket for that either) so I'll ask him.

It's running fine but I have a feeling I shoul dhave gone with the 346xp. I am going to ask raymond if he will order one for me. He doesn't like selling saws anymore but probably will for me. I think.

I am not "unhappy" with the Dolmar yet, just hate to have problems with a brand new saw. I have never had any serious issues with my Husky's and only one with Stihl. So I may have to gravitate back toward orange and light orange.

Max sawdust · « **Reply #40 on:** January 10, 2009, 07:14:50 am »

Update on replacement PS5100 saw:
Runs fine, using it for firewood and wood lot clean up. Got to thinking, it could be that the failure on 30 foot ripping cuts could be the fact that the saw is a high RPM (14,500) saw, and ANY high RPM 50cc class saw would have a problem with big long ripping cuts. With that said.. I went and bought a Husky 372XP for ripping laterals in log work. (It is a proven saw for log work.)

The PS5100 is a fine general woodlot saw that has a couple of nicer features than the 346XP. (I like the sprocket and the fact that the 5100 runs 3/8 pitch chain instead of .325 chain) I do feel the 346xp was more "even tempered" and started a little easier when some warmer than cold. Again, for me dealer support is important and I have a great dealer for the Dolmar.

ladylake · « **Reply #41 on:** January 10, 2009, 06:03:01 pm »

Any saw should be set richer for 30' ripping cuts including you 372

SawTroll · « **Reply #42 on:** January 11, 2009, 05:42:36 pm »

[RSteiner link=topic=33665.msg492554#msg492554 date=1226945469]

I have done a lot of brush clearing with my PS5100. Actually for brush work I want a saw that will rev up quickly and cut the stems rather than pull the saw with a slower moving chain. Last Saturday I helped a farmer friend cut brush and small trees along the edge of one of his fields. I used the Dolmar for about 6 hours. Rarely did the saw run at full throttle for any more than a couple of seconds on the small stuff.

I find it a great saw to use for both brush and larger trees.

Randy
[/quote][/size]

If you want fast accelleration, get the 346xp, it revs up much faster than the 5100 - but don't run it on part throttle - "blipping" is the right way on small twigs.

John Mc · « **Reply #43 on:** January 13, 2009, 09:16:01 am »

Quote from: SawTroll on January 11, 2009, 05:42:36 pm

If you want fast accelleration, get the 346xp, it revs up much faster than the 5100 - but don't run it on part throttle - "blipping" is the right way on small twigs.

Saw Troll - I've heard that statement about not running part throttle a few times now. I do try to follow that recommendation. Just curious why that is. What does part throttle operation do to a saw? I assume it's got something to do with the mixture being incorrect at part throttle, but doesn't the reduced power output offer some protection?

Is it still a problem if you run part throttle when not under load? I've got one saw that's a bit cold blooded. In cold weather, when first started it dies if I let it come back to idle. If I run it at part throttle for a minute or so it's usually OK. I don't like to rev it way up when cold, but I'm wondering if this type of part throttle operation is a problem.

John Mc

beenthere · « **Reply #44 on:** January 13, 2009, 09:48:17 am »

John Mc
I've a friend that I sometimes cut with, and he is a "part throttle" cutter. I often thought it was why he has so much clutch trouble. Seems at part throttle, the chain bites and catches a lot. Seems he doesn't have engine problems. Running a Stihl, 028.

Tom · « **Reply #45 on:** January 13, 2009, 11:39:25 am »

I've been told that it is the chain speed that is important more than the engine RPM's. The saw is designed to drive the chain at the proper RPM for efficiency.

Reving a chainsaw to its designed limits,unloaded,isn't supposed to hurt them. As a matter of fact, it's a way to determine if the oiler is functioning properly. Reving one to its designed limits, under load, is the proper way to use one.

I don't really know, just reiterating what I've heard. I've always been more suspect of someone who continually "gooses" the throttle. That can't be good on any engine. I don't know why folks do it. They do it with motorcycles too. Most seem to have gotten away from the habit when driving cars and trucks, except for some drivers in big trucks.

TexasTimbers · « **Reply #46 on:** January 13, 2009, 01:09:22 pm »

I have a buddy who works for Clark Forklift who told me not to "work" my skid steer at low RPM's. Daid it was hard on the hydrostatic pump, among other engine vitals. Said it was cool to let it idle sitting, or to "half-idle traverse" as long as it isn't doing work or using hydraulics. Maybe putting a load on any type of combustion engine is not a good idea, under most circumstances.

I have never goosed my engines, but I sneak up behind my wife every now and then and goose her in the sides with my index fingers while simultaneously making a loud quacking sound. She pretends to dislike it, but i know it is just an act. The slaps to the cheek sting a little when they connect though.

One time she was taking out the Thanksgiving dinner. What I discovered was, if you goose the chick who is removing the turkey, you better duck or it could be your swan song.

I had to eat crow that year, and it was a very unpheasant experience.

John Mc · « **Reply #47 on:** January 13, 2009, 01:19:11 pm »

Where I got the mixture assumption from was hearing someone say that most chainsaws are set up to run with a good mixture at idle and at full throttle. They also claimed that in between those two extremes, the mixture could be off (too lean). It did not make a lot of sense to me, since I thought that was what a carb was for... blending fuel into the airstream in the right proportions, regardless of throttle setting. I figured maybe a chainsaw cab was just a little different - optimized for full throttle operation.

I was aware of the chain speed issue (always fun to watch someone in the level 1 Game of Logging class try to bore cut "carefully" at part throttle the first few times they do it. In this case, what they think is being careful is actually what's causing them problems).

John Mc

pallis · « **Reply #48 on:** January 13, 2009, 03:47:14 pm »

I bought a modded 5100 that had been run with a pipe for awhile, opened up the muffler, had to rebuild the carb and fool with the intake to make it quit leaking, but it was worth the effort. I run 32/1 mix, in all my other saws, and this 5100 runs great, better than great. I've never blown up or burned up a saw, and I hope this amazing little jewel doesn't change that.

RSteiner · « **Reply #49 on:** January 14, 2009, 06:29:05 am »

The part throttle thing has me wondering just what "part throttle" is. I bought my first chainsaw in 1976 a Mini-Mac 25 followed the next year by a Mac 10-10. Since then there have been a couple of Stihl's, two Sachs Dolmars, and a couple of Husky's, and now the Dolmar 5100.

I have run all the saws basically the same way and have not "blown" one up, yet. Some of them just plain wore out, especially the Mac's after about 5 or 6 years of moderate use. One Dolmar had to be retired because parts were no longer available for the ignition. The Stihl's and the Husky's are still in running condition.

That said, there are times when I run the throttle full open as well as there are times when I may run them with the throttle just under full open without bogging down or lugging the saw. I think the problem with running at half throttle would be one of engine cooling as the flywheel is not moving as much air across the jug and the load on the saw would cause it to run hotter. More RPM more air flow to cool the engine.

Just a theroy at this point.

Randy

cheyenne · « **Reply #50 on:** January 14, 2009, 07:12:55 pm »

I have a Mac Pro 10-10 I still use and beat to death it just wont die. But by the end of the day I'm whipped. Takes two buds for my hands to stop shaking.....Cheyenne

MakitaCS · « **Reply #51 on:** January 15, 2009, 12:29:09 am »

Quote

Takes two buds for my hands to stop shaking

That's what I'm talking bout homeboy, OG style!

So far my "AREA 51" is doing super bad ass.

It's a Grand National in disguise.

Stutz · « **Reply #52 on:** January 10, 2010, 09:13:33 am »

Your 5100 may need the little metal carb boot ring installed, it helps form
a better seal between the carb and intake boot.
part # 181 131 020

I am no expert but I found this info helpful.

Adding extra oil. There are people who use more oil than what the
50:1 ratio calls for. They think that they are doing their saw a favor by
giving it extra oil. This is not true! Too much oil is sometimes as harmful
as too little. Extra oil in the fuel reduces the octane rating of the fuel .
By running the saw with a richer A/F mix you are getting more oil in
to the motor, more fuel to cool it, negating the need to increase the
premix ratio.

Always adjust the carburetor properly rich. This helps
keep the saw from building excess RPM. It also reduces or
eliminates lean detonation which causes heat buildup in the
cylinder. Contrary to what many cutters believe, the saw
actually produces more horsepower when it is adjusted
properly rich. The saw won't scream like a "leaned out" one,
but it will make more stump power. Resist the temptation
to make it sound good.

A technical publication I got once stated that for every one percent
of gasohol, your engine runs 10 degrees hotter. That means a gas
blend with 10% gasohol causes the engine to run 100 degrees hotter.
This added heat along with a hotter burning, leaner mix can lead to
disaster too. Too much heat on the exhaust side creating a seizure
was becoming all too common.

SawTroll · « **Reply #53 on:** January 12, 2010, 04:36:32 pm »

Quote from: RSteiner on January 14, 2009, 06:29:05 am

....
That said, there are times when I run the throttle full open as well as there are times when I may run them with the throttle just under full open without bogging down or lugging the saw. I think the problem with running at half throttle would be one of engine cooling as the flywheel is not moving as much air across the jug and the load on the saw would cause it to run hotter. More RPM more air flow to cool the engine.

Just a theroy at this point.

Randy

I believe it is mostly because most saw carbs have no "mid throttle" jet - the saws simply aren't meant to be run that way!

News:

Author Topic: Any one blow up their Dolmar PS5100 yet? (Read 9080 times)