Stihl 361 tuning

[bwalker]

Is even Meteor made in China now?? sad...

I believe so. There was a post about this sometime back IIRC.
Regardless Meteor cylinders are hit or miss port wise. Some are decent and some are dogs. Personally I wouldn't roll the dice on one.

 

[arto_wa]

I ordered Dukes piston/cylinder set yesterday and will post here once it's been running for awhile.

 

[ApePilot]

That's caused by **** port chamfers of that Chicom cylinder.
You get what you pay for.

I'd think that all that scratching *may* be caused by crap port chamfers, but look at the piston below the first ring.... kinda burnt-looking. That's from too-lean a mixture. Possibly from adding more oil to the mix without adjusting both high and low mixture circuits, or merely not re-tuning the carb when the density-altitude changes, which is most likely.
These carbs without a high-speed adjustable circuit are pure junk. Drilling out a high-speed jet is barely adequate -- it's only good at a DA that you've initially tuned it at.
An intelligent person would wonder why the EPA doesn't merely have an educational program to help educate 2-stroke users on the proper carb-tuning procedures, rather than mandate that no carburetors have adjustable high-speed circuits, and to hell with the environment -- just throw away all those 2-stroke engines and burnt parts with all their associated manufacturing costs, materials and AM parts-manufacturing-associate pollution and replace with new parts that will eventually burn-up because of their mandated BS.

 

[bwalker]

I'd think that all that scratching *may* be caused by crap port chamfers, but look at the piston below the first ring.... kinda burnt-looking. That's from too-lean a mixture. Possibly from adding more oil to the mix without adjusting both high and low mixture circuits, or merely not re-tuning the carb when the density-altitude changes, which is most likely.
These carbs without a high-speed adjustable circuit are pure junk. Drilling out a high-speed jet is barely adequate -- it's only good at a DA that you've initially tuned it at.
An intelligent person would wonder why the EPA doesn't merely have an educational program to help educate 2-stroke users on the proper carb-tuning procedures, rather than mandate that no carburetors have adjustable high-speed circuits, and to hell with the environment -- just throw away all those 2-stroke engines and burnt parts with all their associated manufacturing costs, materials and AM parts-manufacturing-associate pollution and replace with new parts that will eventually burn-up because of their mandated BS.

With poor chamfers it beats up the ring too snd will cause blow by. Or it's running way lean and burning oil that's on the skirt as you suggest.
Alot of guys will burn a saw up and then just replace the cylinder without figuring out what caused the burn down in the first place.

 

[arto_wa]

I'd think that all that scratching *may* be caused by crap port chamfers, but look at the piston below the first ring.... kinda burnt-looking. That's from too-lean a mixture. Possibly from adding more oil to the mix without adjusting both high and low mixture circuits, or merely not re-tuning the carb when the density-altitude changes, which is most likely.
These carbs without a high-speed adjustable circuit are pure junk. Drilling out a high-speed jet is barely adequate -- it's only good at a DA that you've initially tuned it at.
An intelligent person would wonder why the EPA doesn't merely have an educational program to help educate 2-stroke users on the proper carb-tuning procedures, rather than mandate that no carburetors have adjustable high-speed circuits, and to hell with the environment -- just throw away all those 2-stroke engines and burnt parts with all their associated manufacturing costs, materials and AM parts-manufacturing-associate pollution and replace with new parts that will eventually burn-up because of their mandated BS.

The photo was taken after running the Farmertec MS361 clone with the very restricted muffler which came with the build kit, and it was not really possible to hear burbling or four stroking with it so ended up using a tach method, but was not happy at all how the reading was bouncing around.
Poor tach I suppose?

Like mentioned in post #14 earlier in this thread, I now have a unrestricted muffler and with the carburetor now readjusted it is easy to hear the burbling abd engine run cleaning out under load.

I will replace the cylinder, piston & rod needle bearing with Duke's kit later this winter as time permits.