Any one blow up their Dolmar PS5100 yet?

[cheyenne]

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]

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]

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]

....
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!

[patriotsinger]

I know this is an old posting I am replying to, but I am in hopes of saving some folks the aggravation I have ben experiencing re. the Dolmar PS5100S. I bought mine less than two years ago and have less than 10 hours on it and its fried. I was careful to use only gasoline with no ethenol, driving 11 miles to the only store around that sells it. That's all I use in all my small engines. I was careful to mix the oil in at a little more than 50:1 per the instructions that came with the saw. This past December I couldn't get the thing to crank and it turns out the piston is shot.  My dealer passed away around the time I bought the saw and the business closed down so I had to take the saw 45 miles over the mountain to another dealer. The bottom line is that Dolmar will not stand behind the warranty because they say the cylinder and piston is not included in the two year warranty even though the manual states that the engine is covered for two years from the time of purchase.

I would strongly advise against buying one of these saws because the 14,500 rpm is going to cause the saw to overheat on the recommended 50:1 mix and Dolmar apparently is hanging their customers out to dry even though, I have now learned, many others are having the exact same problem I have. I have heated my home exclusively with wood that I go out and get from the woods for the past 27 years. I had a smaller Husquvarna saw that lasted 14 of those years and an old Homelite that took care of the others except the one winter I tried the Dolmar. Neither of these saws ever quit because of a burned up piston. DOLMAR BUYER BEWARE.

[ladylake]

 
Plain and simple TUNE them richer, more torque also found with more fuel.  Steve

[NCFarmboy]

Dolmar came out with an insert (PN: 181131021) to go in the intake tube iirc it was the 2008 service bulletin.  Also went down from14,500 max rpm to 13,800 rpm's.  Another change was a air filter change (PN: 181173190).  You can cut the little teat with the hole in it(bottom of the AF  it goes in the center of the foam circle.)  off old AF and put a screw in it.  Which is basically what they did.  Cut a slot in the foam circle that sits on top of the carb.  Run it @ 32 to 1 13,500-13,800 and you will be fine.  I have seven of them in various stages from stock to WP.  I absolutely Love em. 
Shep

[sawguy21]

patriotsinger, the saw has a one year warranty which includes the piston and cylinder. The two year warranty covers the emission related components, federal law requires that they maintain standards for that period of time.
I work for the Canadian distributor, we saw problems with the PS5100S. They seem to have been set up too lean at the factory and too many dealers were unaware of tuning procedures. They often need to be enriched past the stop on the limiter cap but who am I to suggest breaking the law ;)  The clutch side seal, incorporated in the bearing, is also suspect.

[RSteiner]

Still running my 5100S which is around 4 years old now.  About a year after I purchased the saw the dealer told me that the factory carb. settings are way to lean so I defeated the limiter tabs and tweaked the settings a little.  The saw actually ran better and hasn't got as hot as it did previously.  I am also careful not to run the saw for long periods of time on a hot day.  Limb or cut chunks a little and let the saw rest while I move stuff out of the way.  I am sure I did some damage one day when the saw got pretty hot but it still performs well. 

Also, I add about a half an once more synthetic mix oil to the fuel.  I have been adding a product called Ethanol Shield to all my fuel in an effort to combat the ethanol problems.  A local Stihl dealer turned me on to the stuff.  They have been suggesting all their customers use it in both 2 stroke and 4 stroke small engines for about 2 years.  Since then the amount of issues relating to ethanol have reduced greatly.

Randy

[MakitaCS]

I've ported my 2008 Dolmar 5100s cylinder (a few cylinders
Actually) that ran great as a 5100S worksaw and ended up porting the original cylinder to run on nitrodyne and 30% nitromethane on a Makita 510 chassis and have never had it fail, as a 5100S worksaw or 510 hotsaw. The bottom end are tough. They are a stout saw, particularly as a racesaw.   8)

But I hear Husq Howls a lot now...

[MakitaCS]

Best overall advice that can be given that has been spread around is to remove the limiter tabs to be able to get the motor off the fry zone. Once the limiters are off, you can then richen it up to where it's four stroking off the cuts. The "limitation" is in the caps, no pun intended.

Both the top end and bottom end are tough. There is no need to worry about a 5100 ever melting down, unless those tabs are not removed.

Here's the finger ported Makita 510 Nitro burner operated by EC.

http://www.youtube.com/watch?v=nMoqM14VMag

[MakitaCS]

I have a feeling troll is going to do a cartwheel after reading this .

I'm a BIG Dolmar fanatic, but Husqvarna does build some good motors. I never gave them a thought until recently. From the factory, the 5100 has more power. But yes, it does weight more and does not handle as well IF you are in the woods. If they were dropped from a tree, the 5100 would fair better. The plastic is much tougher as is the muffler, but with that comes a compromise. Weight. However, the 346 is not as light as people make it out to be. But yes, it is lighter and does handle better, particularly for those with back problems. Otherwise, the 5100 is a fun saw to swing around in the bush too. Both have great sounds. The 5100's snarl of the motor banging off the limiter or the tight revs that can be attained on a Husky with the correct porting.

With all that said, the 346xp is a great saw. If you need to buck big wood and don't want to carry that much weight, the 5100s is a good choice. So is the 346. If I had to choose a motor to work with, the Husqvarna large port layouts are a much better design. Larger ports means more flow, period.

Although that Kita 510 nitro burner sure goes fast and strong for having small ports.

But in the end, it's hard to beat a worksaw that has the ability to cut @ 13,000 revs in the cut and sound dang cool doing it. 346xp worksaw sporting finger ports that run through the cylinder wall from the transfer ducts. My buddy Metals406 nicknamed them CT13's  ;D
High compression work done as well.

http://www.youtube.com/watch?v=-38cyvnxNG4&feature=share&list=UUajZbXHo90pcHQr1a1G0WKw

[ladylake]

 If that saw is turning 13000 rpm in the cut it would cut a lot faster if he pushed a little harder and got the RPM down to 9500 RPM where the peak hp is..   Unless this saw is ported a lot.  Steve

[MakitaCS]

No problem. 390FP being pushed and doing it with high revs where it counts. In dry seasoned Canyon Oak. None of the green stuff. This is what I disliked from the mother forum. Heads speaking before really knowing that it can be done.

This motor from Husqvarna is one bad dude. Stock, and only pushing 2 tanks, yes, with the rings not taking a seat yet, this thing was a beast with a 32" bar buried in Euc. No muff mod. It still has no muff mod. I'll post again in 15-20 tanks and I'll let you hear 13,000rpm in the cut. Because that's where it's about now ;)

http://www.youtube.com/watch?v=rmBQC05zMM0&list=UUajZbXHo90pcHQr1a1G0WKw&index=2

[chipsfly09]

I bought a 5100s about 4 years ago and ran about 2 tanks of fuel through it (I made sure it was not running lean out of the box) then it started to lean out-- I pulled the fuel filter (it had one of those felt/fiber filters on it) and replaced it with a plastic one and have had no more trouble.  Maybe this has been discussed already.   I am very careful not to run that saw in a lean condition due to all I have read about problems associated with this-- lean out of box, intake boots coming loose or cracking, air filter problems etc.  I run 40:1 baileys synthetic oil.  I like that little saw and would like for it not to give up prematurely--( yes I am saving for a 346xp or maybe that new 500 whatever xp 60cc.)

[ladylake]

Any saw will cut the fastest at the rpm where peak hp is somewhere around 9000 to 9800 RPM on stock saws, letting them scream cuts slower and will wear them out faster.  Steve

[MakitaCS]

Who wants to cut at 9K? Not me.

346FP being pushed some with tight revs in the cut. In dry Canyon Oak. Peak HP is past those numbers...

http://www.youtube.com/watch?v=QhH0tds7iR4&list=UUajZbXHo90pcHQr1a1G0WKw&index=6

[MakitaCS]

BTW Dolmar fanatics, not alls is lost. That Kita 510 nitro burner that was sporting a finger ported 5100S cylinder...

It beat out two 346xp motors for 1st place  :D

[ladylake]

Most on here are taliking about stock saws which make peak hp around 9000 to 9800 rpm and should be run there.  Steve