Dolmar 5100S blew up.

[Nipper]

Hi everyone!

First post.

This is not troll or hate time, I need some advice...

I purchased a Dolmar 5100s last year and used it a few times to cut firewood. It was fun while it lasted.
I am not a pro mechanic (but a decent one) and I take very good care of my equipment. My last Craftsman saw lasted over 20 years so at this point I surely wont knock it.

I was cutting a log Friday and the 5100s just quit. Pulled the rope and knew there was no compression.

Took it to my dealer who is very good and probably one of the best in town and they told me the fuel mixture was correct. They removed the exhaust and the piston was scored badly. They are telling me this was due to an excessive amount of ethanol in the gas. They said the ethanol washes the oil off the piston.

I have no way of knowing the amount of ethanol in gasoline. I dont think this will be covered by warranty since its been a year.

Do you guys think this is right? If their explanation is correct I cant see purchasing a "nice" saw again. I cant know if the gasoline is good so it seems like I cant win this one. If this is true then all I can do is buy cheap saws and throw them away.

Personally I would think the engine and oil manufacturers should know what kind of gas is out there and create their products accordingly.

$450.00 down the drain...... :bang:

Are you guys seeing this issue with fuel? Seems like a bunch of 2-cycles would be dead if this is the case. All my other 2 cycle engines are fine using the same gas.

 

[gink595]

I've read here where people are sayiing to watch out for ethanol. All is not lost though you can buy a new piston and cylinder for around 200ish. If that is someting your intersted in doing I will glady take it off your hands

 

[blsnelling]

Ethonal in and of itself will not hurt your saw what so ever. However, it does have to be tuned correctly. I can almost guarantee you that your saw was running too lean. That is the cause of neraly every 5100 failure I've heard of. My guess is that your dealer saw the H needle wass against the stop and thought it was fine. He probably never even put a tach on it. The only solution is to cut the tab off of the limiter cap and tune it properly with a tach. You need to find a new dealer that knows what he's doing!

 

[TRI955]

opcorn:

 

[edisto]

They said the ethanol washes the oil off the piston.

That's a new one...

 

[thomas72]

blsnelling is right. More than likely the saw was scored either by lean fuel setting or an air leak.

 

[mountainlake]

Ethonal in and of itself will not hurt your saw what so ever. However, it does have to be tuned correctly. I can almost guarantee you that your saw was running too lean. That is the cause of neraly every 5100 failure I've heard of. My guess is that your dealer saw the H needle wass against the stop and thought it was fine. He probably never even put a tach on it. The only solution is to cut the tab off of the limiter cap and tune it properly with a tach. You need to find a new dealer that knows what he's doing!

Right, either you need a dealer that WILL tune it right or learn to do it yourself which is a lot better. There have been a lot of saws burning down all brands. Ethonal gas does not store well, use Stabil or Seafoam, dump the old gas in your lawnmower and if it really screams and likes to bog easy after storage DON'T run it clean the carb and adjust it right. Steve

 

[blsnelling]

There have been a lot of saws burning down all brands.

I've heard of no other saw having the problems they've had with the 5100S. I believe it's truely a great saw, but the factory often sets them too lean and dealer support is nearly non existent. I have no idea why a company would make such great saws and then not support them!

I personally would settle for nothing less than a repaired saw. Go to the top if you have to. It's not your fault it came from the factory so lean, and your dealer doesn't know how to setup a new saw!

 

[Fastcast]

To test your gas for ethanol, you'll want to pour one part mix to one part water in a clear Mason type jar and shake it up. Let it set 20 mins or so and the water, fuel and ethanol will separate. This will tell you how much ethanol is in your gas.

The ethanol is the creamy mixture between the two....I believe this is how it works, its been awhile, someone will correct me if I'm wrong.....I've seen local stations around here with 20% ethanol.

I found a station with no ethanol and that's the one I buy my mix fuel from.

 

[woodshed]

That really sucks, another 5100s failure. Hate to say it but shoulda had a 346XP, you just don't hear of these kind of problems with the orange ones. I would kick and scream at the dealer until he helped you out, has to be some kind of recourse. Did he tune it out of the box or just hand you the saw and wish you good luck? Hope you get some sort of assistance.

Scott

 

[blsnelling]

That's fine if you want to find out if your fuel has ethanol in it, but that is not the cause of your problems. What your dealer told you is a bunch of crap! I'm almost positive the Stihls come from the factory tuned to run on a percentage of alcohol. That is not the problem!

 

[blsnelling]

That really sucks, another 5100s failure. Hate to say it but shoulda had a 346XP, you just don't hear of these kind of problems with the orange ones. I would kick and scream at the dealer until he helped you out, has to be some kind of recourse. Did h tune it out of the box or just hand you a saw and wish you good luck? Hope you get some sort of assistance.

Scott

There's likely nothing wrong with the saw. Why turn this into a brand war? The 5100S is a fine saw.

 

[woodshed]

Agree, all saws will run on a ethanol mix fuel if tuned properly. Crap dealer in my opinion.

Scott

 

[blsnelling]

Agree, all saws will run on a ethanol mix fuel if tuned properly. Crap dealer in my opinion.

Scott

+1

 

[7sleeper]

Ethonal in and of itself will not hurt your saw what so ever. However, it does have to be tuned correctly. I can almost guarantee you that your saw was running too lean. That is the cause of neraly every 5100 failure I've heard of. My guess is that your dealer saw the H needle wass against the stop and thought it was fine. He probably never even put a tach on it. The only solution is to cut the tab off of the limiter cap and tune it properly with a tach. You need to find a new dealer that knows what he's doing!

opcorn:

7

 

[striperswaper]

calm down Brad
to get you off the subject, how is the 3120?

 

[woodshed]

Not a brand war but can you honestly name any other saw has had as many lean failures as the venerable 5100S? You certainly don't hear about 346XP, MS260 or even 7900 saws blowing up with low hours obn them, especially by the dozen. Might be something else to this, design flaw or something not even related to fuel mixture.

Scott

 

[Fastcast]

That's fine if you want to find out if your fuel has ethanol in it, but that is not the cause of your problems. What your dealer told you is a bunch of crap! I'm almost positive the Stihls come from the factory tuned to run on a percentage of alcohol. That is not the problem!

Was just trying to help the gentleman out, as far as testing his fuel, to see just how much ethanol is in it.....Also for future reference, for the OP or anyone else who may be interested. If you're not, move on.

Are Stihl saws set from the factory to run on 20% ethanol?

 

[blsnelling]

OK, I know I'm on a soap box ranting. this just hit a nerve and ticked me off. Not that the OP posted it, but that the saw gets an undeserved bad rap. Now...before you all think me just a Dolmar fanboy, that is not the case. I'm not particularly fond of the 5100 and much prefer a 346. But that has nothing to do with this situation. This man chose to buy a 5100S and got a great saw when he did so. Unfortunately, dealer support is VERY lacking. How many 5100s have we heard of being burnt up because they were set too lean? Lots more than it's competitors! But again, that's not the saws fault. If you like a 5100, BUY IT! Just make sure you have the carb properly tuned and it should last you a long time. Rant off

Are Stihl saws set from the factory to run on 20% ethanol?

I seriously doubt it. Probably more like 10%, but I'm not sure. Again though, that's not a problem if the saw is tuned for it. It's only a concern for long term storage.

 

[blsnelling]

calm down Brad
to get you off the subject, how is the 3120?

I know, I know, but I kind of enjoy a good hearty sermon every now and then, lol The 3120's not here yet.

Not a brand war but can you honestly name any other saw has had as many lean failures as the venerable 5100S? You certainly don't hear about 346XP, MS260 or even 7900 saws blowing up with low hours obn them, especially by the dozen. Might be something else to this, design flaw or something not even related to fuel mixture.

Scott

You are absolutley right. I just don't believe it's a problem with the saw itself. If it is, it's certainly never come to light that I'm aware of. In nearly every case it turns out to be that the carb was set too lean.