Did something Dum- straight gas into Stihl

[LostWater]

Ok, I did something really stoopid, I didn't pay attention and ran straight gas into both of my stihls. The cylinder and the piston is scored on each.

To fix, am I correct that I would just need to get a new cylinder (jug?) and piston for each? I have the workshop manual and do pretty complicated stuff on my cars and stuff. Any gaskets would be needed?

Any and all help would be appreciated.

Thanks in adavance,

Mark
Christiansburg, VA

 

[eyolf]

For certain your pistons are toast, but search back threads...we've talked about using acid to clean aluminum smears from Nicasill cylinder bores. Look again, because if you don't need to buy the jug, you're plenty cash ahead.

 

[eyolf]

By the way, don't feel like you're the only one that does stuff...I was trying to finish up last Saturday, ran out of gas, and refueled my saw with pre-mix. Put premix in the oil tank, too.

Also forgot to put the caps back on the tanks, and when I went to start the saw, I gave myself a nice gas bath. If there wasn't a bit of snow on the ground, I'd proabably have started a fire!

 

[LostWater]

OK Found a good fix

I will be getting a jug and cylinder from the saw shop. I am trading some computer help for a discount.

Am I correct in assuming that I will need to dissasemble the top end and get the tube (correct term?) that connects the piston to the conrod pressed in?

Also, the saw shop said they didn't see any gaskets listed. They said if they did it, they would use some hi-temp gasket material.

Is that the right way to do it?

Is my 031 (the other one I Fubared up) worth fixing too?

Thanks for the positive comments, I don't feel like such a dum*ss anymore.

Mark

 

[bwalker]

Its also highly likely that your main bearings and crank are shot as well. You may be able to remove molten aluminum from your cylinder with muritic acid, but I bet the plating is shot anyway, so why bother.
As far as using sealer to make a gasket. Your dealer is a moron(like alot are) for suggesting this. If you are going to spend the time to rebuild them, do it right.

And to answer your question, yes you have to remove the top end to pull the wrist pin. You also will need to replace the pin, clips and small end bearing when you put the new piston in as I am sure they are shot as well. Make sure you check the bearings. It would suck to replace everything and then have the big end rod bearing go, destroying everything in the process. Big end rod bearings almost always fail when ran with out lube.

 

[JimL]

Originally posted by RockyJSquirrel
IMHO I would replace the factory gasket with a factory (or similar) gasket. Your dealer is worthless if he cannot find the base gasket on his parts list. The crap in a tube is for shade tree mechanics that don't know any better (Yes this is an overly broad, inflammatory statement).

Don't forget your intake and exhaust gaskets also.

So id be a moron if i recomended you a tube of stuff for your cylinder on your 039?

 

[tony marks]

well bud ,,ive never done that. and u know what.. thats nearbout a miracle in itself. it ll happen tommorow,,i know

 

[stihltech]

Model

What model of saw are we talking about?

As for the bottom end, they tend to be pretty tough. They seem to stand one bout of no oil OK.
Get a small cylinder hone, the kind with 3 spring loaded stones. Chuck it in a drill and clean the cylinder. The piston material is usually deposited on the cylinder. Since it is soft, it will remove first. The cylinder is hard enough that this type of hone won't hurt it. As long as there are no scores into the cylinder wall, it will be OK.
Look for bluing on the lower connecting rod journal. If there is, then I would be skeptical of the crank.

The hone will not work on the consumer saws due to the finger porting that goes up the side of the cylinder.

 

[bwalker]

Get a small cylinder hone, the kind with 3 spring loaded stones.

I cant think of a better way to chip a cylinders plateing. Every two cycle builder out there says no three finger hones.

So id be a moron if i recomended you a tube of stuff for your cylinder on your 039?

If you are reccomending people replace gaskets with silicone, Yes you would be a moron.

 

[jokers]

Slightly undersize ballhone, judiciously applied is the only way to go. Follow up with emery cloth on the port edges.

Uh Ben, for saws that have a horizontally split crankcase there is no gasket, just a tiny bit of sealer.

Russ

 

[bwalker]

Jokers, Hence this comment.

reccomending people replace gaskets with silicone,Yes you would be a moron.

 

[NeTree]

Try www.jackssmallengines.com

They always have what I need, and ship the right freaking part EVERY time, unlike my local dealers.

If you're going to do the top end, might as well go whole hog and have no worries. Compared to piston and jug, the rest of the replaceables are cheap insurance.

Don't put RTV where there should be a gasket.


Also, MARK YOUR CANS.

 

[NeTree]

Originally posted by RockyJSquirrel
Not only mark your gas cans, but I further recommend using different size cans. I use a 1.5 for regular gas for my mower and use a different shape 1 gallon can for mix. If you have someone helping you, you can glance over from 100 feet away and see if they are filling the chainsaw out of the correct can. Anticipate what might be confusing to others (or even yourself) and change it so there is less chance of making a mistake.

If you have two identical gas cans and only one is mix, sooner or later somebody will put straight gas in the chainsaw- even if the cans are marked.

On a similiar note, I keep three cans on the truck. Two are 5 gallon "straight" gas, and a smaller 1 gallon can for the mix. I mix up a gallon as I need it, and there's never any doubt which can to take it from.

It also gives me some reserve gas in case the truck or chipper runs out in the middle of nowhere.

 

[jokers]

I`ve got three, 2 gallon cans clearly marked saw gas. Since I`ve started running MX2T I have also started putting the dose of oil in the cans as soon as they are empty, then when I fill up with fresh gas I don`t have to worry about whether it has oil in it or not. Haven`t ruined anything yet(hear dull sound of knocking on punky, wooden head).

Russ

 

[bwalker]

I put a zip tye on the handle of cans that contain mixed gas.

 

[wmthrower]

I once did that to my father when I was young. He threw the saw on the ground but luckily it didn't hurt anything. I told him what gas can I used right after he started it.

 

[Crofter]

Its best not to use a tag or system only you understand. If anyone else has access to the cans that might borrow or replace with something else or somewhow do you a favour........ Nothing beats a tag that says Mixed Fuel Only. I picked up some at a hardware store that had an insert on the tag where you can also write the mix ratio. It still isnt fool proof tho. When you start getting old enough to hide your own Easter eggs, what you gonna do?

Frank

 

[tony marks]

yrs ago i loaned my sawto an old timer.,,cause he was getting own in yrs.
went to get it and he kinda grinned at me . said son it cuts good but dont last long long enuff to suit me. he had run the gas out and put his lawnmower gas in.
to that old homelites credit,it broke loose and run fine afterwards.oldtimer never knew what happened.

 

[stihltech]

chrome?

I don't do McCullochs. Most new saws are nikasil ar chromium impregnated. No chipping.

But then, I am a hacker. Funny how my saws seem to work afterwards.. 20 years of good luck I guess.

 

[jbrody44]

I always look to make sure the mixed fuel has a color to it. I usually use echo mix and it is blue. This doesn't tell me that the mix is to the right ratio, but at least I know it is not straight gas. If you make sure to look at the fuel as you put it into the saw you should never put straight gas in, unless of course some oils use no coloring agents.