Anyone rebuilt a chainsaw?

I'm ordering an OEM cylinder, piston, and rings to rebuild my grandma's little Stihl MS180C. She ran straight gas in it and scored the cylinder and piston. It still runs if you give it some gas and isn't seized up completely, but I haven't done this kind of repair before and was wondering if anyone has some tips for a newbie. I am mechanically inclined and will be taking my time, this is more of just a fun project for me but I also don't want to end up wasting my time and money, so any advice is appreciated. Thanks!

 

rebuilding the carb at the same time?

 

Yeah. Here's a good resource for parts.

https://store.chainsawr.com/

 

I do rebuild small tools like chainsaws, snowblowers, lawnmowers, weed wackers, trimmers, etc during my spare time.

If the piston is scored, yes, replace it and the rings, but if there is damage to the cylinder itself, you have to replace it as well (or have it bored if it can be). Don't put a brand new piston in a damaged cylinder.

then while the chainsaw is taken apart, it would be good to rebuild the carburetor and put new fuel lines

 

Yeah the whole block is part of the kit with the piston and rings. I'll check that website @PintSize linked for the carb and fuel lines. Do I have to replace the carb if the saw only has about 5 hours of run time on it? It's a pretty new saw.

 

if the carburetor is not old, no need to rebuild it.

If the saw did sit for a long time with gas inside, take it apart and clean it with some carb cleaner. Old gas often cause lacquer buildup in the carb or lines

 

It just sat for about a day or so with new gas (that was supposed to be used in her generator but the cans weren't marked...)

 

one day is ok. I meant more like a full season or even a year or two

 

Yeah I figured as much. I think I'll just start with the block, piston and rings and see how it runs after that. It'll be a nice $100 limbing saw if it works out! My dad already bought my grandma a new one and told her to label her cans haha

 

What about crank bearings and the connecting rod bearings? The oil in the gas lubes all of those. Running straight gas probably messed them up as well.

 

I can check into those as well. I'll probably pull it all apart before I order the parts to see if there's anything else I need.

 

MS180C is a good saw, and parts can be had quite cheap. I've done crank seals on similar models before. For $100 you could probably have a new crank/rod, piston/rings, cylinder, crank bearings/seals, and have a brand new saw.

One tip is USE THE RIGHT GASKET MAKER for the clamshell. I used Permatex Motoseal, gotta have something specifically designed for dealing with 2 strokes. Don't assume because it says safe for oil that it's safe for gas....and whatever you do DO NOT use black RTV. Get the right stuff, it will save a lot of trouble.

 

Thanks for the heads up! I probably would have used the red high heat RTV I used for my URD short shifter. I'll have to see what it says, but better safe than sorry. I'll just go get a tube of that stuff you used.

 

No problem!! Glad I was in time. Here is a pic of it....couple bucks at O'Reilly's iirc.

 

@Sandman614

 

I've only done intake boots, impulse lines, carb kits. Not big hardware repairs needed so far.

My 10yo Husky had fine sawdust IN THE CARB! It was getting hard to start. I'm trying to figure out how the fine dust got in. The air filter is ok, maybe an air leak where the cleaner boot mates with the carb?

 

Buy Grandma the Stihl premix gas..... i wasn't a believer in it due to the cost, but it is nice picking up the saw in the spring after sitting all winter and having it start on 2 pulls..... At my Stihl dealership if you buy a gallon of the Stihl premix they will double the warranty.....

 

If it was run on plain gas it didn't run long enough to damage anything other than the bore and piston I would wash it out with a fuel mix before you put it back together. Stihl did run a deal on oil but it was for a new saw it just extended the warranty. The 28" one of 3 is the last resort saw it's got to be pretty big to fire that one up the limbing saw is the fairly new MS171. IMHO there are two chain saws the ones that won't start when you need them the most and then the Stihl's

 

Well here's a little update, I finally got around to tearing this thing apart and got it done late last night. I haven't fired it up yet because I don't want to wake up the whole neighborhood lol. Thanks for all the suggestions!

 

Well it's been a while since I rebuilt this saw, and from what I hear its still running well! Sold it to my dad for the cost of parts. Thanks for the tips guys!