Dolmar 5105 scored piston

[OBX Koastie]

I am new to this site but not to cutting wood. My first saw was a Craftsman Pro Saw made by Poulan, moved up to a Homelite 360, to a Stihl 029, to a Stihl 036, to a Stihl MS441, then a Stihl MS362, newer 441 after my boys liked my old one too much and now I have a MS441, MS362, Echo CS-360 and a Dolmar 5105 in the shop with a scored cylinder and piston with metal transfer

I bought the saw new off Ebay but when received it was four years and three months old. Should have sent it back but Dolmar told me they would stand behind the warranty. First time out I used about 2-1/2 tanks of fuel, and the saw did not run right. My son who was with me and a tree climber said' "Dad, this thing isn't right. Take it back." Kept cutting off after making a cut. Took it back to a local Dolmar dealer and they had it for about 1/2 an hour and gave it back. I had it out last weekend cutting wood for our church and after about 2-1/2 tanks, it quit. Thought it was out of gas, checked and it was still 1/3rd full so I refilled it. Tried to start it, NADA. No compression. Took it back to the dealer and they called me today to say that Dolmar will not cover the damaged cylinder and piston due to insufficient oil in the fuel. But they will fix it for $380 plus tax!

Here is where it gets interesting. I use only Shell 93 octane non-ethanol. I use only Stihl Ultra full synthetic mixed approximately 40:1 (3 ounces of Ultra to one gallon of gas.) I drain my tank after every use and let the saw idle to run the carb dry making sure not to rev it when low on gas and running lean. I have had my fair share of saws and have never had a problem like this. I was using the 362 and the Echo 360 with the same mix. It is the same mix I use in my Stihl blower, Dolmar edger, Echo Shred-N-Vac and all my saws. Prior to the Stihl Ultra I ran only Amsoil synthetic and believe I know how to mix gas and oil having done it without incident for almost 45 years.

Any ideas or insights. I bought the saw thinking I was getting a great pro 50cc saw. Now I am not so sure!

Kim

 

[porsche965]

Since others mentioned also that the saw isn't running right obvious there was a problem not related to fuel mix since your other equipment is fine.

I would guess that there is an air leak or a carb problem causing the lean situation.

They are good saws, I have two, no problems along with the 7900s.

 

[ncfarmboy]

Very sorry to hear about your saw and Dealer problem. 5105 is a very good Pro saw. I have 6-5100's and they are excellent saws, good value to boot. I got all of mine off Ebay 3-NIB and 3-scored. Repaired them. P&C kit is around $170, Piston kit $70. Easy saw to work on fix it yourself. If cyl isn't gouged you can clean the alum transfer off the cyl. w/muratic acid applied with a q-tip. Another thought write the Corporate office in Germany a "NICE" letter explaining your problem. They have in the past done the right thing. The main thing is to find out the cause of failure.
Shep

 

[exSW]

Stuff degrades sitting on a shelf for four years.I'd say some kind of air leak.I wouldn't expect to much help from your dealer.You walked in with a toasted saw you bought off Ebay.The nice letter/Email to Dolmar's German HQ might be some help.PM me if you want to cut your losses and lose this saw.

 

[spike60]

Has it already been more than 4 years since the 5105 replaced the 5100?

 

[Stihl-Pioneer]

Has it already been more than 4 years since the 5105 replaced the 5100?

Mine was built in 09!! Time flies !! :msp_wink:

 

[spike60]

Mine was built in 09!! Time flies !! :msp_wink:

Yikes! It sure does, :msp_scared:

 

[7sleeper]

Stuff degrades sitting on a shelf for four years.I'd say some kind of air leak.I wouldn't expect to much help from your dealer......

That is the first time I have ever read of that! Degrading without fuel inside!? Can't wait for the complaints on Stihl 660 models that haven't been made since three years....

7

 

[SawTroll]

Running 2 1/2 tanks through a saw that isn't running right is an obvious operators error! :msp_scared:

Also, the early 5105s were much closer to the 5100S in some regards than the later ones, and basically suffered from the same issues.

 

[7sleeper]

Running 2 1/2 tanks through a saw that isn't running right is an obvious operators error! :msp_scared:

Also, the early 5105s were much closer to the 5100S in some regards than the later ones, and basically suffered from the same issues.

But these issues were already eliminated by 2006 if I remember correctly. So all later production date models were "problem free", if you are thinking about airleak of the very first models, after running for extensive amount of time.

7

 

[SawTroll]

But these issues were already eliminated by 2006 if I remember correctly. So all later production date models were "problem free", if you are thinking about airleak of the very first models, after running for extensive amount of time.

7

The leaking intake booth was fixed in nov 2006, as I remember it - but the issues I referred to were not those air leaks! :msp_wink:

 

[mountainlake]

Running 2 1/2 tanks through a saw that isn't running right is an obvious operators error! :msp_scared:

Also, the early 5105s were much closer to the 5100S in some regards than the later ones, and basically suffered from the same issues.

Have to agree, if not running right and you keep on running it it's your fault. Probably just tuned too lean as quite a few new saws are now days. Steve

 

[exSW]

That is the first time I have ever read of that! Degrading without fuel inside!? Can't wait for the complaints on Stihl 660 models that haven't been made since three years....

7

Seals,gaskets,foam filters and lines do break down if dry over time.Hit them with heat,fuel and temp changes after years of inactivity and **** happens.The earlier Dolmar fuel lines that weren't ethanol compatable are one example.Ask anyone who has a taken a low time or no time vintage(or not so) machine and tried to use it at the rated capacity and they will tell you the same.Been there,done that and fixed the leaks.

 

[SawTroll]

Have to agree, if not running right and you keep on running it it's your fault. Probably just tuned too lean as quite a few new saws are now days. Steve

Those Dolmars were notorious for being tuned lean for the US market, to "pass" EPA - and Dolmar USA failed to teach the dealers to correct it at the point of sale.
In addition, they tended to run very hot, because of badly designed top end cooling. That was allegedly fixed on the 5105, but the "evidence" tells me it didn't help a lot, before max allowed rpm was reduced from 14,500 to 13,800.

 

[SawTroll]

Have to agree, ....

I understand you don't like to agree with me - but the forum would be rather dull if everyone agreed on everything!

 

[OBX Koastie]

Running 2 1/2 tanks through a saw that isn't running right is an obvious operators error! :msp_scared:

Also, the early 5105s were much closer to the 5100S in some regards than the later ones, and basically suffered from the same issues.

I take strong exception to blaming this on operator error. The only thing the saw was doing was occasionally cutting off when coming out of a cut in soft pine. Other than the the saw seemed to have appropriate power for a 50cc saw with one or two tanks of gas having been run through it. After the Dolmar dealer, who by the way had no Dolmar saws in his entire shop tuned it, it ran the same as far as power but did not cut off after making cuts in 8-12" red oak limbs. The pine was 14-16" diameter.

I forgot to include that when I received the saw I advanced the high speed jet to get the richest mixture possible within the limiting adjustment just to avoid this situation.

The saw was manufactured in September 2008 and I purchased it in December 2012. It did not come in its original box so I don't know where it was sitting. The Ebay individual selling the saw is a distributor and a parts source for Dolmar. Because of what I read on this and other sites and not willing to drive over 160 miles round trip to a dealer who does sell these saws, I went the Ebay route paying $30 less than full list.

If this were the first saw I ever owned then I might be willing to accept this blame. But I've run saws big and small for over 40 years, have always treated them with great respect keeping my chains sharp, my filters and saws clean, and my fuel slightly over-rich in two stroke oil. The Stihl Ultra is designed to protect at ratios as lean as 100:1 and I was running 40:1.

So before you go blaming something you know nothing about on operator error, you probably need to consider all of the causes for this issue besides the one you chose to select. I can think of at least six that have nothing to do with the fuel-to-oil ratio which is what the dealer is blaming this on and on whose theory you would appear that you agree. According to your way of thinking, there is nothing that could have caused this failure other than operator error. If you don't have anything meaningful to add you probably should troll this site for individuals willing to accept your lack of knowledge when it comes to diagnosing two stroke engine failures.

 

[7sleeper]

Seals,gaskets,foam filters and lines do break down if dry over time.Hit them with heat,fuel and temp changes after years of inactivity and **** happens.The earlier Dolmar fuel lines that weren't ethanol compatable are one example.Ask anyone who has a taken a low time or no time vintage(or not so) machine and tried to use it at the rated capacity and they will tell you the same.Been there,done that and fixed the leaks.

As far as I understood, the OT said the production date was over 4 years ago but the saw itself was unused. So if that was the case there shouldn't be any break down what so ever. Because if that is the case I know of a humongous amount of saws sitting in stores with production dates over 5 years old that still haven't been sold. Stihl, Husqvarna and all the others sure are in deep sh!% if they all suffer from your described problems. Because they are all going to die in their first few outings..... But then again they will only say wrong fuel.... But I have never heard of this problem before on these forums that old saws die during their first few outings because of defective "rubber" parts. And I believe that there would be quite some talk here and otherwhere on not buying saws with production dates older than 1 year! Well folks don't get a Stihl 660 because they haven't been produced since 2011! Don't want to invest in a lot of replacement parts before ever using your "new saw".

Those Dolmars were notorious for being tuned lean for the US market, to "pass" EPA - and Dolmar USA failed to teach the dealers to correct it at the point of sale.
In addition, they tended to run very hot, because of badly designed top end cooling. That was allegedly fixed on the 5105, but the "evidence" tells me it didn't help a lot, before max allowed rpm was reduced from 14,500 to 13,800.

I might be wrong but as far as I know the max rpm is 13500. And also those were changed quite early during the production cycle of the 5105 predessesor 5100/5000. And that they were running any hoter than any other saw at 14500 is new to me. But this has already been debated here so many times.
http://www.dlg-test.de/pbdocs/4037_05.pdf
And you are correct about the lean setting. Just like so many other manufacturers.

7

 

[mountainlake]

Within the limiters can still be too lean on quite a few newer saws, they need to be pulled to adjust right. If the melted the piston on the exhaust side it WAS lean and a good operator would recognize that it was lean. Really doesn't matter what the cause was. Steve

 

[SawTroll]

.....


I might be wrong but as far as I know the max rpm is 13500. And also those were changed quite early during the production cycle of the 5105 predessesor 5100/5000. .....

It was eventually changed to 13,500. However, all 5100s were 14,500 - as were the early 5105s. Then it changed to 13,800, and later to 13,500.

The European PS5000 always was speced at 13,500 max though - maybe that is what confuses you?

 

[SawTroll]

Within the limiters can still be too lean on quite a few newer saws, they need to be pulled to adjust right. If the melted the piston on the exhaust side it WAS lean and a good operator would recognize that it was lean. Really doesn't matter what the cause was. Steve

Yes, the limiters are there to avoid you setting the mix too rich for EPA regulations, not to help the user setting it rich enough!