Stihl 024 Rings

[autobaun70]

I picked up an 024 cheap at an estate sale a while back. Chains that were with it NIB were worth more than I paid for the saw. Basically left it laying around until recently, and got it out as a spare during storm cleanup. After a carb cleaning it would run fine briefly, then lose power. Piston didn't appear scored, but after working through everything else I could think of, pulled the jug, and found a broken upper ring. Zero scoring on the piston or jug. Aside from the gaskets, anything else I should be doing while I'm in there?

 

[Mad Professor]

Get an OEM gasket set they come with seals.

Look over the chamfers on the ports since you had a broken ring.

Check P/C clearance at the skirt. If you don't have mics feeler gauges will give you a rough idea. New is ~ 0.002-0.0025", if you are getting close to twice that might be time to think about the piston.

Good time to replace impulse and fuel hoses (check filter). Look over the intake boot real well for cracks. If you have the tools a pres/vac test when it's back together.

Did you put a kit in the carb when you cleaned it?

 

[autobaun70]

I definitely did a full carb kit when I went through it, and have the intake boot on order. Fuel hoses are new on both sides.

I have access to a full machine shop, mics, etc. every day at work.

Can you describe in more detail what clearances need to be measured? I have built a few two strokes before, but that was 10+ years ago and trying to recall all the pertinent details. Also which seals would need to be replaced beyond the cylinder and exhaust gaskets? I was not planning on splitting the case and don’t see any more…but definitely won’t claim to be an expert.

Long-term the goal for this saw is to serve as back up to my 346XP and other bigger saws at the farm. Most stay at the farm, and I keep my 346 at home for infrequent misc stuff around the neighborhood. Needless to say it’s gotten run hard the past 2 weeks….and my planned backup didn’t do too much backing up. I generally figure if I need one saw I am a pinched bar away from needing 2 saws. Also figure it may be a bit handier said than the 346 for smaller jobs.

 

[2StrokeFondler]

I picked up an 024 cheap at an estate sale a while back. Chains that were with it NIB were worth more than I paid for the saw. Basically left it laying around until recently, and got it out as a spare during storm cleanup. After a carb cleaning it would run fine briefly, then lose power. Piston didn't appear scored, but after working through everything else I could think of, pulled the jug, and found a broken upper ring. Zero scoring on the piston or jug. Aside from the gaskets, anything else I should be doing while I'm in there?

View attachment 1210747

What Mad Professor wrote. If you get a gasket kit, do the seals too. Those are as old as every other rubber part on the saw.
Just like the AV mounts... I have two 026 carcasses lying around where the fuel tank rubbed away a substantial part of the magnesium case cause the AV mounts were done.

 

[autobaun70]

What Mad Professor wrote. If you get a gasket kit, do the seals too. Those are as old as every other rubber part on the saw.
Just like the AV mounts... I have two 026 carcasses lying around where the fuel tank rubbed away a substantial part of the magnesium case cause the AV mounts were done.

Can you clarify what seals you are referring to?

 

[cookies]

I pointed out the crank seals in the url image, having access to your tools you could easily make seal drivers to fit over the crank so as to not need to separate the case...the seals fit into the bearing and against the crank or the bearing has a wide internal race the seal rides on.
https://prnt.sc/-xWZQ7GGPqSk

 

[autobaun70]

I pointed out the crank seals in the url image, having access to your tools you could easily make seal drivers to fit over the crank so as to not need to separate the case...the seals fit into the bearing and against the crank or the bearing has a wide internal race the seal rides on.
https://prnt.sc/-xWZQ7GGPqSk

Gotcha. That makes sense. That should be zero issue to do. I’ll add those to my parts order

 

[Mad Professor]

Gotcha. That makes sense. That should be zero issue to do. I’ll add those to my parts order

The seals come with the gasket set and the set is less expensive than individual seals. The flywheel side will be a PITA to pull (small), don't scratch the crankshaft surfaces. Be careful installing the new seals that the flywheel keyway, or the clutch threads on the other side do not damage the seal.

You want to measure the P/C clearance at the skirt. The pistons are made with a taper and are largest at the skirt. When I checked some new 038 pistons the taper was ~0.005"

I forgot to mention the checking/replacing the AV mounts but someone covered that.

Is the saw a 024 or 024S? The 024S can accept 026/260 P/C as they share the same stroke.

 

[autobaun70]

Great info. Thank you for your help. It’s a regular 024AV.