Stupid Chainsaw tricks..

[Jibber]

I had a gas can mixup and ran my almost new Stihl Chainsaw on regular gas.. as in no oil in the mix. I'd probably cut three or four sections of a fairly large tree when it just kept shutting down, as if it were running out of gas. I figured maybe It was sucking some air, the tank was about half full, so I went to refill it and discovered the mix up. I drained the tank, added mixed gas and the saw fired up and ran great.

My question.. What kind of damage might I have done? It seems to run fine, recoil starter pulls nice, compression seems good.. At least it didn't seize. I just worry I did some kind of nasty internal damage to what is basically a month old saw with just a few hours on it.

duh.

and I learned to keep my mixed gas in cans that look very different from unmixed gas.

 

[Birdhunter1]

Chances are if it ran fine after this then it is probably ok. I did that once too, felt pretty stupid but three years later it's still running great.

One thing I usually do on my saw (Stihl 029) is to run slightly thicker mixed gas/oil through it to coat everything real good with oil. Like instead of mixing 50:1 gas/oil for the saw I may run a few tanks of 40:1, you're plug won't last as long but everything gets enough oil. Usually 1-2 tanks of 40:1 and it's time to refill the gas can and then it's back to 50:1.

 

[PILOON]

Richer oil mix---

Back when I was building my log cabin, the old logger fellow that helped me always added enough oil to make his saw smoke!

Reason was we were building in black fly season and the smoke kept the flies at bay!

Works with muskeetos as well!

When in doubt use more oil---you might choke some plugs but at least you won't burn out the saw.
However prolonged use of richer mixes can cause carbon deposits and even plug some mufflers.
Also carbon can score the cylinder walls and piston, so don't overdo it.

 

[Jibber]

I've always run a little richer than 50:1.. but I've heard from one saw mechanic who says Stihl doesn't recommend it. Forget exactly what it was supposed to do.. clog the muffler or something like that.

But, I guarantee that more oil is better than no oil.

 

[BlueRidge]

Manufacturer recommendations are influenced by emissions requirements. You can safely assume that they are recommending a leaner mix than what is best for the longevity of the saw. 40:1 isn't going to clog things up.

 

[BlueRidge]

</font><font color="blue" class="small">( My question.. What kind of damage might I have done? It seems to run fine, recoil starter pulls nice, compression seems good.. At least it didn't seize. )</font>


Ypou might have shortened its life, but not be able to see anything obvious. One thing you can do is to pull the mullfler and look at the piston. Rotate the engine a few times so you can see it. If you see obvious scoring, well, run it til it dies. The damage isn't covered by warranty anyway, so you might as well get some use out of it.

 

[RMAL]

2 strokes motors run hotter with a rich oil mixture.Less gas passing through the engine (diluted by the oil).Lean mixtures will make any engine run hot.Sounds crazy but its true. Al

 

[hillslider]

I have been told this as well. The local Stihl guy told me this a few years ago. The gas actually cools the piston and having a highr oil content will cause it to run hot.

 

[RMAL]

Too much oil will also gum up the inside of the engine.Run the mixture thats in the manuel or on the oil can,no more no less and your engine will be happy.

Al

 

[RobertN]

This was explained to me by a pro moto-cross engine builder. If it is 50:1 oil, run it at 50:1, if 40:1, run at 40:1. Always go by the oil manufacturer spec. While you may have a 20 year old saw with a manual that says run at 16:1, it will also spec a specific oil to run at 16:1... Run a modern 50:1 oil at 16:1 and it will, well, not run /forums/images/graemlins/crazy.gif

Unless, of course, you want to burn things up... /forums/images/graemlins/shocked.gif