Stihl MS241 build

Looks great, Steve

 

Franks mang.

 

Thanks. Hopefully you get to run it in May.

 

Something like that. Lol

 

Got a bit more done. First I checked to see if my go to 1/5 scale rc car filter, that I put on saws, fits the 241. The answer is yes after removing the factory air filter twist lock mount. It clamps right on the stihl part on the carb. It doesn't interfere with the controls. Hood will have to be cut out obviously.

 

I have everything removed so I can pull the cylinder tomorrow. I timed it today and it was a real pain with the tiny plug and decomp hole for viewing through along with the reflections from the cylinder walls. Anyway, out of curiosity I asked Kevin what he gets with timing a stock 241 and we are a few degrees off from one another on exhaust and transfers but same on intake. Also, the uppers have staggered openings that I couldn't see with all the reflections. I use a flash light looking for the first crack of light in the exhaust port and do my best to see the uppers through the plug hole but the 10mm plug hole is tiny. He uses a different method that sounds like its more accurate. I don't plan on raising the exhaust or transfers anyway but I still like to be as accurate as I can. I might try again tomorrow with a magnifying glass to hopefully see in there better. Anyway, these are the numbers I got.

 

Well done.

Another DDM air filter saves the day.

 

Thanks bud. Those filters work well. I won't run one an off-road RC car, because they live in a cloud of debris, but on a saw, I see no fines. They aren't paper either. They are washable. I've out them on 3 saws so far. This one will be number 4. I'll have to order one here soon.

 

If I can't see in there real good I'll run the ring up in there with the piston to the top of the xfer I'm measuring, then put the piston back on the con-rod, put the cylinder back on and rotate up to just bump the ring. It's usually more accurate than peeking in a tiny hole at an odd angle...

I'll shut up now since this is a family channel...

 

Lol. Yeah, I was a bit frustrated.

 

More 241 stuff...


Cylinder is perfect. Piston shows most of the machine marks.

 

Numbers without base gasket. I used a magnifying glass to try and see the transfers better.

 

Great pictures, the close up shots have great detail.
Thanks.

 

Macro setting gets in close.

 

I took the cylinder to my trusted local welding / fab shop. They declined welding that mount to the cylinder out of concerns of warping. I'm going to run it. It's solid and if it ever gives me trouble, I'll send it Shawn Carr.

 

He will get it done, he is magic man on stuff like that.

 

That's what I hear.

 

I have an update. Firstly I'm glad I didn't sell this to anyone as it needs a flywheel. Its out of round, well, it doesn't center on the crankshaft correctly. It also wobbles. They must have over tightened it trying to compensate for the sheared key. $100 for a new one. It might take 2-3 weeks to get here. Also my OCD wouldn't let the AV mount go so it's on it way to Shawn Carr tomorrow. Lastly, because my nephew wouldn't take my porting slot, for the 543xp, I have reserved with Kevin, I'm being "forced" to have him port it. lol. Different build than my prescious. No machine work. Just gasket delete and whatever other magic he does. The beater 241 will be my go to dirty wood / GTG saw going forward. I should have it all back together before Denny's GTG. Currently the plastics are boiling in black dye.

 

Stealth Bomber look.

 

What??? Not blue raspberry???