Dolmar 5105 scored piston

[TXLiquid]

my 94 s10 was in storage alot only 48000 in 15 years found out all the bushings dry rotted tank had sediment from sitting alot all the rubber in the truck was junk. storage and sit time is horrible for any machine from a vaccum to a big rig...period

How would that have anything to do with the OPs chainsaw?

A 19 year old USED truck sitting around (probably out in the elements even) with fuel in it is totally different from a 4 year old never fueled chainsaw!

If you go to a dealer and buy a crank seal you don't know how many years it may have set on the shelf before you bought it.

 

[OBX Koastie]

Not on any new saw , every one I've had has been tight counterclockwise. Steve

Had a very interesting discussion with the owner of the Dolmar Authorized Dealership. He is of the opinion that as long as you have the proper oil/gas mixture, you can run the saw as lean as you want and it will not cause any problems. He said that per the Dolmar pictures they receive with their failure analysis information that the only way to score the piston and have metal transfer is lack of lubrication.

He then told me how running the engine with too much lubrication will cause all kinds of problems like caked spark arrestors, spark plugs caked with carbon, carboned up exhaust valves (had to explain that there are no exhaust valves in a two-stroke), overheating from trying to push the extra exhaust gases through the muffler, etc. Then he tried to tell me that it could have been the result of a clogged fuel filter "because every time I laid my saw on the side and re-fueled it dirt and debris entered the fuel and would clog the filter." When asked if he had any indication of any of these issues with my saw he went off on another tangent. I really wish I had been recording it.

I am convinced that they will not be the ones repairing my saw! And they are probably the ones that messed it up when I took it in there.

Still no contact by the zone rep so I am waiting to talk with him after he has heard this dealer's story.

Hopefully Dolmar knows of issues with running two stroke engine under load in a lean condition and that the results are the same as running it with a poor oil/gas mixture.

The saga continues.

 

[dugide]

Had a very interesting discussion with the owner of the Dolmar Authorized Dealership. He is of the opinion that as long as you have the proper oil/gas mixture, you can run the saw as lean as you want and it will not cause any problems. He said that per the Dolmar pictures they receive with their failure analysis information that the only way to score the piston and have metal transfer is lack of lubrication.

He then told me how running the engine with too much lubrication will cause all kinds of problems like caked spark arrestors, spark plugs caked with carbon, carboned up exhaust valves (had to explain that there are no exhaust valves in a two-stroke), overheating from trying to push the extra exhaust gases through the muffler, etc. Then he tried to tell me that it could have been the result of a clogged fuel filter "because every time I laid my saw on the side and re-fueled it dirt and debris entered the fuel and would clog the filter." When asked if he had any indication of any of these issues with my saw he went off on another tangent. I really wish I had been recording it.

I am convinced that they will not be the ones repairing my saw! And they are probably the ones that messed it up when I took it in there.

Still no contact by the zone rep so I am waiting to talk with him after he has heard this dealer's story.

Hopefully Dolmar knows of issues with running two stroke engine under load in a lean condition and that the results are the same as running it with a poor oil/gas mixture.

The saga continues.

to bad you didn't ask questions here before you burn't it up. sounds like there was running issues for awhile. but dolmar may fix seeing as you did take it to a dealer and the problem continued. interesting on how this turns out.

 

[SawTroll]

Had a very interesting discussion with the owner of the Dolmar Authorized Dealership. He is of the opinion that as long as you have the proper oil/gas mixture, you can run the saw as lean as you want and it will not cause any problems. He said that per the Dolmar pictures they receive with their failure analysis information that the only way to score the piston and have metal transfer is lack of lubrication.

......

No wonder a lot of those saws got "burned", and they handled it badly, with and attitude like that! :msp_scared:

 

[mountainlake]

That dealer should be banned from saws for life.. Plus those dealers are why you need to tune a saw your self. Steve

 

[OBX Koastie]

That dealer should be banned from saws for life.. Plus those dealers are why you need to tune a saw your self. Steve

Steve,
I watch the videos and try to understand how to detect when the engine is four stroking but after having served on ships in the CG my hearing is not what it should be. So I really can't tell what they are listening for. And while I would be more than happy to tune them after they were out of warranty; I was always adjusting my old Craftsman and Homelite 360 but they were pretty simple saws and my hearing 40 years ago was much better. I am also not sure enough of myself to void a warranty by removing the stops and adjusting the carburetor myself. So here I am, fairly knowledgeable because I did my homework and thought I was buying a durable saw, only to learn otherwise.

If Dolmar does give me a new saw, I have no idea where to take it to have it set up properly. Most places within 100 miles are rental and auto repair shops that appear to sell these saws as a sideline. If I get a new saw I may just sell it on Ebay and go for the Echo CS-500P or more likely a Stihl MS-261. Two excellent dealers both within 15 miles.


But I do appreciate the input from the people much more knowledgeable than myself and with thousands of years more experience.

 

[ncfarmboy]

I too have trouble hearing. Buy a tachometer. Tune to 13,500 and you should be safe with good power. Max rpm's on 5100 is 13,800 down from 14,500 which is in the score your piston zone. Not trying to start an oil war but believe it or not more is better to a point. I run mine @ 32:1 full synthetic 93 octane non-E gas in my stock and ported saws. An additional benefit esp in ported saws crank bearings live longer.
Shep

 

[mountainlake]

Yes, get a tach and get rid of that dealer. 13500 sounds real good. Steve

 

[dolmarfan]

I have a dolmar 5000 wich is the european version of your saw.
I tuned mine at around 13000 rpm to be on the safe side and in the cut is doing about 9000rpm.
Mix at 50:1 for a long time no problem.
Mix today 45:1 seems to be working better and cooler!

 

[OBX Koastie]

I have a dolmar 5000 wich is the european version of your saw.
I tuned mine at around 13000 rpm to be on the safe side and in the cut is doing about 9000rpm.
Mix at 50:1 for a long time no problem.
Mix today 45:1 seems to be working better and cooler!

So I guess what I am hearing is that mixing it religiously at 40:1 with Stihl Ultra and Shell 93 non-ethanol and even then draining it and allowing it to run at idle to drain the carb after every use should not have caused the piston and cylinder to transfer metal as told by the dealer to Dolmar rep. I don't disagree that running it lean was likely the cause of the failure.

And I have been considering a Tach and now I am sure that I will be getting one. Any preferences or am I opening another can of worms?

 

[mountainlake]

By all means get a tach and would have good to have a dealer that tuned your saw right, my local Dolmar dealer is just as bad with burnt up saws but he won't pull the caps and richen them up. Steve

 

[Adirondackstihl]

Had a very interesting discussion with the owner of the Dolmar Authorized Dealership. He is of the opinion that as long as you have the proper oil/gas mixture, you can run the saw as lean as you want and it will not cause any problems.

Your dealer is an idiot

and on top of that.....running 40:1 in a saw that is tuned to run @ 50:1.........it will run lean

HAND

 

[SawTroll]

Your dealer is an idiot

and on top of that.....running 40:1 in a saw that is tuned to run @ 50:1.........it will run lean

HAND

:agree2:

 

[OBX Koastie]

Your dealer is an idiot

and on top of that.....running 40:1 in a saw that is tuned to run @ 50:1.........it will run lean

HAND

Now I am really confused! Are you saying that changing the oil to gas ratio in a saw determines whether the saw runs rich or lean. If that were the case, would it be better if I ran saw at say 100:1 and that would have it running super rich? (FYI the Stihl Ultra full synthetic can run at up to 100:1 ratio and provide protection. Stihl doesn't recommend it but their oil is that good.)

Just asking because I thought the carburetor high speed adjustment was what determined the amount of gas entering the cylinder and ultimately the amount of mixed oil that it was carrying. I have never seen nor heard of running the oil gas ratio a little higher than specified would cause the engine to seize. In fact the old timers that I talked to when I first started cutting always ran their saws a little rich in the oil to gas mixture. As they said spark plugs and cleaning the exhaust port was cheaper than replacing the saw.

Someone help me understand this statement.

 

[mountainlake]

The reason is with more oil in the gas the gas gets thicker and doesn't flow through the jets as easy, the more oil the leaner it will run and should be tuned for it. Get that tach, saws need to be tuned from summer to winter, the gas you use, oil ratio, elevation etc. Steve

 

[hoeyrd2110]

why argue if it makes a saw leaner or not 50:1 just ain't enough oil for a long happy life. i tell my residential customers 40:1 and commercial 32:1. i'm putting myself out of business cause i haven't had any hard parts repair on a 2 stroke since they all heeded my advice

TXliquid my post was about degrading parts with age, my truck was garage kept till i got it. and no rubber degrades in air just fine without fuel. how is that different from rubber bushings on the suspension of a vehicle which are dry?personally had my truck been broken in more and not a cream puff it would have served it's perishable parts much better. i've had a couple NOS saws come thru over the years and almost everyone has had degrading rubber parts, intake boots, fuel line (again never fueled) even the carb diaphrams get stiff just from age...

 

[Adirondackstihl]

Now I am really confused! Are you saying that changing the oil to gas ratio in a saw determines whether the saw runs rich or lean.

That's exactly what I'm saying! There are enough oil threads around here to drive a maggot off a shat wagon.

Fuel causes a rich or lean condition, not the oil. More oil = less fuel. Fuel cools the piston and cylinder, not the oil. Oil is a lubricant.
Your high speed jet needs to be adjusted for temperature, altitude, octane rating, humidy and yes.....even oil ratio!

 

[Bingo]

Dolmar 5105

Wow...lots goin on here. You seem to have a good grasp of how your 5105 should run and how it's not running correctly. I don't know if you just have a bad one or your dealer is just an idiot (and he looked at the saw?...this is something the rep should know eh?). But with your background in engineering you can ID problems that shouldn't exist w/an original manufactured product. It sounds like you are justified in being disappointed w/a saw that you've treated well, seemingly w/o help from your dealer. I'm hoping you and the Dolmar zone rep can have a decent conversation one of these days (away fm the dealer), and Dolmar will actually do something for you. Your dealer might think you are to blame but it sure doesn't sound like it. In the future I'd think you would say screw these dealers and just go ahead and "mod" the saw (remove the limiters...do the muffler and re-tune the carb W/A TACH), and get on with it, richening it up to where it actually needs to be to run correctly...i.e., w/o doing harm. Seems to be a given nowadays that any fuel-related problems w/a saw will be denied under warranty by the dealer/corp. That's their out. I.E., the warranty ain't worth spit exept at point of sale. Some manu seem to do this but I hate to think it's a trend...That does not bode well for repeat business!
I have a PS 510 that I got 6 months ago...2011 manu and China assembled (gasp!)...It's a good runner. I was going to MM it and re-tune but am holding off. I've only backed out the H speed screw to the limiter and it's running at about 13,100 or so rpm (this is a tach-tune and way below the limited-coil setting I know...but it runs fine there, not a screamer but lots of torque and pull)...I run it w/Dolmar syn at about 45:1 mix (yes, 87 at the pump too...never had any saw or whatever balk at that). And, I must say, it's seems to be a strong, if stock, runner. I'm not touching it yet for some reason. If it goes down I might build it up to a 5105 if I can...But I don't see any problems w/it yet. I think Dolmar makes a good, well-constructed, very comfortable, saw that has been sabotaged by our EPA...but it seems their standards must be re-adjusted by US from the beginning...warranty be damned I guess. Dealers are coerced by huge fines if they actually help you do it right. They are running scared and that has made them hesitant when it comes to actually doing the right thing for the end user of their saws. Mine offers good advice but hesitates to offer actually doing it. No problem as we both know his situation (he's quite open about it)...Too bad you don't know a local guy that works on saws and says screw the manu...I just make saws run...Perhaps you have some friends that do some serious cutting that know a local like that?...Anyway, I think Dolmar makes a good saw and you will prevail if you stick to the issues at hand....Just wanted to jump in here and tell you to keep going and hope it works out in your favor. The best advice you've received is to go around the dealer and just do it yourself...Keep going and let us know how this turns out...If it were my saw I'd get it rebuilt and use it...or sell it and move on...Sucks but your choices are limited at this point. I like Dolmars and plan on getting a 6401 or 420 one day.

 

[OBX Koastie]

That's exactly what I'm saying! There are enough oil threads around here to drive a maggot off a shat wagon.

Fuel causes a rich or lean condition, not the oil. More oil = less fuel. Fuel cools the piston and cylinder, not the oil. Oil is a lubricant.
Your high speed jet needs to be adjusted for temperature, altitude, octane rating, humidy and yes.....even oil ratio!

Just for fun:
Bitzer 2009 (almost 200 posts The 40:1 would actually give the saw better lubrication and cooling, but if the saw is not modded it would not be necessary. I don't think synthetic or regular makes a difference its just how you mix it.
Blsnelling 2009 (almost 40,000 posts) Mix a good synthetic oil at 40:1 and use it in ALL of your chainsaws. 70 years old to new. Forget that "other brand" comment. That was a lawyer talking to cover their butts.

NWCS 2005 (almost 200 posts) use 32:1 mix in everything, from my 12year old 21cc echo brush cutter to my largest saws..(99cc) using good mix i have had no problems with 50:1 other than normal wear.. 32:1 i get less wear than that.. another reason i use 32:1 is i live in a MAJOR dust area.. most of my area is sand and dirt roads.. more oil helps if an air filter starts letting some grit in.. also seem to get a little more grunt out of my saws

Rbtree 2005 (Almost 500 posts) Many say 50-1 and dino mix is fine....but most serious saw users and builders swear by the better mix and richer mix ratios.....

Del 2005 (Almost 20,000 posts) 40/1 mx2t here in all my saws.

I haven't read the newer posts but if you are not an expert on chainsaws, buy what you believe to be a reputable brand, do exactly what you have been doing in all your Stihl and Echo products without problem, and it takes a dump is that operator error or a POS saw?

 

[Adirondackstihl]

Did you not read what I wrote?
32 or 40 is fine...... If your saw is tuned for it

I'm done