Chinese parts on the way

[huskihl]

Definite 4;stroke I doubt it was much over 11k. I know how to tune a saw and a race bike. Piston is scuffed on intake side as well. Have cylinder off will check OOR tomorrow. It is possible after porting I didn't clean up the piston and cylinder enough, but I doubt it. Brake cleaner scrubbed it in a sink full of purple power and scalding water, passed the white rag testvafter cleaning. I know the carb was adjusted according to a fresh rebuild. Keepnin mind these are no name am parts anythingbis possible

Maybe the intake port wasn't beveled completely? A tiny spot left over can be a problem

 

[tickhound93]

If intake port wasn't beveled correctly you should in theory catch a ring, especially at higher rpms when compression is forcing rings outward. Guys I've bored and ported many cylinders, including 2,strokes. Keep suggestions as well as numbers coming. There seems to be scarce info on ring end gap for bore size, compression etc? I know my rule of thumb for a 4 stroke is .004 of gap for every inch of bore. However too tight of ring end gap would not explain scuffing on intake side. Detonation may be a culprit? But not likely. 89 octane gas in a saw pushing upward of 180 compression isn't really ideal, but I would have heard detonation. I hate to say it I'm leaning toward cylinder OOR or I flat out missed some debris from porting, but I've never done that.

 

[huskihl]

Idk. Is the scoring in one spot or across the intake port?

 

[tickhound93]

Its all across. Some everywhere in the cylinder. It will live, but who knows how long. After port work I re chamfered the ports using 180 grit emery cloth on a home made mandrel, assembly was smooth piston moved with no hesitation by rotating flywheel.

 

[huskihl]

Hmm. Debris in the carb or air filter? Or cold seizure

 

[tickhound93]

No debris in carb, fresh clean kit. As gar as filter goes its seen son use, but was blown out gently before being installed. I should post pics tomorrow if I get a chance.

 

[MustangMike]

4 stroking means a little "break up" when at full throttle but not in the wood. It should clear up as soon as you put it in the wood. There are many saw tuning videos you can watch. If the saw is too lean, it will run too strong and burn up. Saws should be adjusted a little too rich for break in, just to be safe.

The BB kit may need a richer carb adjustment.

 

[a. palmer jr.]

I agree with Mustang Mike but I will add that some saws are a little harder than others to hear this transition from 4 to 2 stroke.

 

[Rx7man]

I'm getting a Hutzl 272 top end kit with crank bearings and seals.. should be here in a week or two... I'll let you know what I find. If possible, mic the piston across the skirt and compare it to the bore.. remember that the thrust face of the piston is the intake side of it.

 

[tickhound93]

Yeah it runs like it should. I got a whole fleet of saws I tune, this one is the same. Definitely not tuning issue.
Looks like dirt ingestion or uneven skirt expansion. I'll mic the piston and bore

 

[Stihlofadeal64]

Which Hutzl kits are you guys using for the MS290 to MS390 conversion? I have a donor saw that needs a top end. It looks like most of the Chinese sellers are selling the same stuff but I can't say for certain. I view one kit that was the whole engine for like $77.00 and a few top ends which included the jug, piston, rings, seals without the crank and other stuff. Someone chime in...

 

[tickhound93]

Which Hutzl kits are you guys using for the MS290 to MS390 conversion? I have a donor saw that needs a top end. It looks like most of the Chinese sellers are selling the same stuff but I can't say for certain. I view one kit that was the whole engine for like $77.00 and a few top ends which included the jug, piston, rings, seals without the crank and other stuff. Someone chime in...[/QUOTE
Earlier I posted my experience with a whole 250,engine from huztl and it didn't turnout so good, but I have heard that the 290,engines work alright. Ask definitive Dave, he sells huztl and will tell you if they work. I was going to do a Chinese 390 on my 290, but daf wanted the saw soni did an OEM 390 kit

 

[dougand3]

I've put top ends on Husky 55 five times. Most were in FarmerTec packaging. I bought them from Huztl, Wangluo18 and machinedoctoronline. I'm thinking they are different sales groups for FarmerTec factory.

 

[tug]

I was talking to one my relatives about saws ,he is a mechanical engineer for a defense company. I mentioned bearings he said they have source US made bearings and sometimes they are not available and they have to try Chinese made ones. He said if they have a failure it is almost always these bearings. Just food for thought, I have used aftermarket parts with good success. But, I might stick with better quality bearings.

 

[Definitive Dave]

Which Hutzl kits are you guys using for the MS290 to MS390 conversion? I have a donor saw that needs a top end. It looks like most of the Chinese sellers are selling the same stuff but I can't say for certain. I view one kit that was the whole engine for like $77.00 and a few top ends which included the jug, piston, rings, seals without the crank and other stuff. Someone chime in...

get the labeled Farmertec top end, it says farmertec on the jug and is hands down as good as OEM (oh no he didn't, oh yes he did), I cant keep them in stock, add cabers and oem piston pin bearing and don't look back
DD

 

[Stihlofadeal64]

get the labeled Farmertec top end, it says farmertec on the jug and is hands down as good as OEM (oh no he didn't, oh yes he did), I cant keep them in stock, add cabers and oem piston pin bearing and don't look back
DD

Thanks Dave, I was thinking just what you said. I bought one of the kits early on, and it has been in a "firewooder" saw for a long time now. There was quite a bit of banter in those days as to whether these kits would last. The guy who has it is as happy as a pig in slop with his saw and he cuts quite a bit of firewood with it. I modded the muffler and tuned it to run. My question was directed here because that has been a few years ago and I have not purchased anything in that realm since. All the other stuff has been OEM.

 

[tickhound93]

Definitive Dave, op here. Hit me up when you get new 025/250 engines to try out. I'll be your guinea pig, got an 025 laying around. Support ourvmembers/dealers friends!