Dolmar 5100s died

[ericjeeper]

Tach smack

Listening to the saw will tell you everything. You can't set all saws to a tach.Especially once they have been modded. Or if they have a limiting coil. One could lean a saw way to far and it still be reading ok on the tach.Due to the limiter.Listen to the burble.

 

[huskystihl]

True but I don't think a 170 would last long at 17,000. I got a 270 that leaned all the way out with the caps on it is still to rich so yes I agree. I have noticed more inconsitencies with stihls carberation lately versus the husky's i've purchased over the years. That could be just because I tend to buy more stihls but nonetheless these are coming off production lines and should be pretty much cookiecutter so why is one of my 270's dead on and the next is pig rich.

 

[huskystihl]

Since Dolmar invented the gasoline powered chain saw, they are not quite Johnny Come Lately

I know the history but they obviously did something wrong marketing wise or production wise or something. By the way how ya likin that 211? I got one that was kind of a joke when I handed to my ground guy and it just wont quit, in fact it might be skid loader proof with that flexible plastic body. It's the second saw that gets fired up every morning and one of the last to go in the truck and just keeps going. I showed the local dealer the saw the other day and we both agreed it's gonna die of ugliness it looks so bad, and it's only a few months old.

 

[SawTroll]

I have a 5100 new in Dec... are the coils limited ??
My Stihl tack will show 12500 any higher it goes wild ..... and I know it is up around 1400+ ...on my 346, the tack is fine ....

It should be limited at 14500rpm - it sounds like yours have a bad coil.

 

[tkuhe]

New 5100 owner

Hi everyone, first post, total noob, and a new Dolmar 5100s owner. Thanks to everyone who posted on this forum, I am very happy with my purchase.

In reading the manual I noticed that Dolmar rec'ds running 91 ROZ gas. 91 ROZ is the equivalent to 87 CLC here in the states. I would guess that a lot of owners may be hurting there saws a little by running a higher octane. Just a thought.

I also noticed that the manual says the 5100 has a decompression valve which it doesn't, or at least I haven't found it, so maybe the manual is off?

Thanks again for such a great forum.

 

[huskystihl]

Hi everyone, first post, total noob, and a new Dolmar 5100s owner. Thanks to everyone who posted on this forum, I am very happy with my purchase.

In reading the manual I noticed that Dolmar rec'ds running 91 ROZ gas. 91 ROZ is the equivalent to 87 CLC here in the states. I would guess that a lot of owners may be hurting there saws a little by running a higher octane. Just a thought.

I also noticed that the manual says the 5100 has a decompression valve which it doesn't, or at least I haven't found it, so maybe the manual is off?

Thanks again for such a great forum.

I've run 93 octane in every saw i've owned and no issues outside of a couple bad 5100's. I keep hearing people talk about the saws running lean which was never an issue with mine. They were set correctly, I recently spoke with a dolmar dealer up in toledo and he verified the exact same 5100 issues that I had. Dirt passing through the filters, he in fact stop selling them due to that and stated until they come out with a new filter like they did on the 7900 that it was more trouble than profit. He also noted that the waiting time that customers are expereincing is not dealer fault but waiting to get an answer from dolmar on the work. Being a reputable dealer he just began fixing many of the saws knowing that it wasn't operator error and wound up losing money therfore leading to no more 5100 sales. He did state that he had quite a few 7900's out and only seen minor issues but nothing like the 5100's. Proven facts, they have a problem with what could be a very nice saw and they need to address it before it starts costing them sales across the board! I've already seen to dealers drop the dolmar products and one of them could have owned the market by being the only dealer in a fifty mile radius.

 

[tkuhe]

My dealer confirmed that the 5100 should be run with 87 octane and not higher.

 

[blsnelling]

My dealer confirmed that the 5100 should be run with 87 octane and not higher.

Directly from the manual.

Fuel mixture
The engine of the chain saw is a high-efficiency two-stroke engine.
It runs on a mixture of gasoline and two-stroke engine oil.
The engine is designed for unleaded regular gasoline with a
min. octane value of 91 ROZ. In case no such fuel is available,
you can use fuel with a higher octane value. This will not affect
the engine.

 

[davido30093]

ROZ vs R/M

Are you saying that 91 ROZ is the same as 91 R/M?

 

[blsnelling]

Are you saying that 91 ROZ is the same as 91 R/M?

Sounds like it is the equivalent of 87 US octane. I'm surprised. Mine all get Premium Unleaded.

From Wiki:

...the octane rating shown in the United States is 4 to 5 points lower than the same fuel elsewhere. 87 AKI octane fuel, the "regular" gasoline in the US and Canada, is 91–92 RON in Europe. 93 AKI octane fuel, the "premium" gasoline, is 97-98 RON in Europe.

 

[davido30093]

Yep.

91 RON equates to approx. 86.45 R/M (AKI).

Originally posted by E_SolSi@Jul 17 2005, 12:48 AM
In Europe 98-octane gasoline is common and in Japan even 100-octane is readily available at the pumps, but this octane nomenclature is misleading to Americans as foreign octane ratings are derived entirely differently from our own... So, like every other measurement system it seems that everyone else uses a different scale than we do, but unlike most other instances where we have had the good sense to create different units of measure in this case we all use the same name...
Japan and Europe use a system called RON or Research Octane Number to determine the octane rating of their gasoline, while stateside we use a system called AKI or Anti-Knock Index to determine gasoline's octane rating... Interestingly, to further complicate things it would seem that our own AKI system is actually derived from the average of the RON system and another more complicated system referred to as MON or Motor Octane Number... So, to recap our methodologies for measuring gasoline's octane rating are different, but share some common elements...
So, with the commonality of RON in mind a good rule of thumb is as follows, multiply the foreign RON Octane rating by 0.95 and you will have the US AKI equivalent.

( RON Octane Rating x 0.95 = AKI Octane Rating )
98 RON Octane x 0.95 = 93.1 AKI Octane (US measure)
100 RON Octane x 0.95 = 95 AKI Octane (US measure)

So, as you can see the 93 or 94 octane fuel we are all paying an arm and a leg for is actually quite comparable to the higher octane fuels found in Europe and Japan. The people whom have to worry about low octane rating are our friends out west in places like California that are subjected to substandard 91 octane.
91 AKI Octane (US measure) = 95.5 RON Octane

 

[huskystihl]

It's all rubbish! 93 octane in everything and no issues.

 

[huskystihl]

My dealer confirmed that the 5100 should be run with 87 octane and not higher.

The dealer is wrong. The manual says higher will not effect the engine. I dont even like 87 in my lawnmower.

 

[tkuhe]

The dealer is wrong. The manual says higher will not effect the engine. I dont even like 87 in my lawnmower.

You are correct, using higher octane will not affect the engine or its performance in any way.
So why exactly to you use it?

 

[Edge & Engine]

Directly from the manual.

Fuel mixture
The engine of the chain saw is a high-efficiency two-stroke engine.
It runs on a mixture of gasoline and two-stroke engine oil.
The engine is designed for unleaded regular gasoline with a
min. octane value of 91 ROZ. In case no such fuel is available,
you can use fuel with a higher octane value. This will not affect
the engine.

The current manuals say to use fuel with a minimum octane value of 87. (apparently revised for US)

 

[huskystihl]

You are correct, using higher octane will not affect the engine or its performance in any way.
So why exactly to you use it?

Try higher octane once and you'll know why. Trust me I try to squeeze a penny into a nickel but it's money well spent. It will make the saw perform better but wont hurt it is what the manual should say. I've heard of guys running jet fuel, now that might be a little extreme.

 

[litefoot]

Try higher octane once and you'll know why. Trust me I try to squeeze a penny into a nickel but it's money well spent. It will make the saw perform better but wont hurt it is what the manual should say. I've heard of guys running jet fuel, now that might be a little extreme.

Yes, you're right, running kerosene in a saw would be a little extreme. I think you meant AvGas which is 100 octane low-lead. Without getting into the whole octane thing again which is :deadhorse:, I have tried AvGas which should, by your reasoning, be even better than 93 octane. But it ain't. None of my saws like it. I've gone back to 87. I don't think a stock saw has sufficient compression to tell the difference between 87 and 93 octane.

 

[nmurph]

Try higher octane once and you'll know why. Trust me I try to squeeze a penny into a nickel but it's money well spent. It will make the saw perform better but wont hurt it is what the manual should say. I've heard of guys running jet fuel, now that might be a little extreme.

i know there are saws that were diesel, but i have not heard of a kerosene powered saw. that's cool. you could use the same fuel in your lantern and saw when you go camping.

 

[davido30093]

Octane rating

Remember that the octane rating is a measure of the fuels anti-knock charactistics, NOT the quality of the fuel. Do you remember:
When the US gasoline was rated by the "Reseach" method instead of R/M (AKI)?
When you could pull up to the pump and get 98 octane fuel everywhere?
When GM invented the "ethel" lead additive to raise the octane level in gasoline?
When Standard Oil was one company before being split into three companies by anti-trust lawsuits?
When some companies, like AMCO, used a higher grade of gasoline to get the higher octane rating instead of using additives?
Yes, higher octane gasoline could be problematic for some engines BECAUSE of the additives used to get the higher anti-knock characteristics. Remember that higher octane does not necessarily equate to a better grade of fuel, in fact, in most cases, it is just the same fuel with some anti-knock additives. (No longer lead though). The people who build the saws have a pretty good idea of what is the best fuel for them. Follow the manufacturers recommendations and you should be OK.

 

[blsnelling]

I have tried AvGas which should, by your reasoning, be even better than 93 octane. But it ain't. None of my saws like it. I've gone back to 87. I don't think a stock saw has sufficient compression to tell the difference between 87 and 93 octane.

Neither quality nor octane makes much difference for the typical saw. We proved this at the GTG two weeks ago in Indy. The test saw was my 064 with a port 066 topend. Compression is about 150 PSI. The fuels tested were:

1. Sunoco 94 Pump
2. VP C10 100
3. 100LL AvGas
4. 95 Pump - No ethanol

There was only 3 seconds difference in all the fuels. That little amount may simply be operator difference. Just for the record, it was the lowest octane fuel that made the fastest cut time, Sunoco 94. But like you said, this is not a real high compression saw. It might make a difference on a 200 PSI saw, but that's not what most saws out there have.

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