Calling all saw mechanics

Ok here's the deal. I got this ms250 for next to nothing. It cranks and runs but won't idle. Idle screw won't do anything. When pulling the handle, it feels like it has too much compression. So I thought it maybe will need a piston.

Well the piston, crank, oil seals, rings all look really good. Cylinder wall has zero marks. It has a OEM carb and crank but I think the piston is aftermarket. Not sure about the head. Here's my question. The original owner said that it would crank once per day and run fine as long as you kept it running. After it shut off it wouldn't crank again. He removed the carb and cleaned it and put in a new impulse line and new oil seals and it didn't change anything. Idle screw didn't help when adjusting.

So being it felt like it had too much compression, I was looking for a bind somewhere. The only place I found was possibly where the connecting rod connected to the crank. It has a super wide gap in it and could have a lot of play. I'll upload a pic as well showing the gap. The rod does NOT wobble but it can slide back in 4th on the bearing. What do you guys think? I may just slide a eBay carb on it and try it.

 

I think Scotty has nailed it. Also like Scotty said the side ways movement is normal on the rod. Problem is the carb.

 

Thanks boss fleabay time.

 

Maybe rebuild the carb yourself after it got a bath in an ultrasonic cleaner, with an oe kit. I've used 2 cheapo chy knees kits and I won't buy another. Welsch pug wouldn't fit, metering lever spring was different... never again.

 

A friend had similar symptoms out of a two stroke mini tiller last week. Reved out but no idle. Idle jet did nothing.
I counter the turns to full seat, then backed the idle jet all the way out, blew the hole out with carb cleaner. Set the jet back to the original position. Idled decent. Needed a small adjustment. It had been plugged from setting.

 

I bought an 044 that the seller said he rebuilt carb and didn't change the way it ran. Stumped him and he thought saw needed something major. I put a new carb on it and it ran great. I'm with Scotty,do the carburetor.

 

Is this a single screw carb, or does it have both H and L screws along with the LA screw?

 

Yup the Chinese carbs work great!
I put them on everything, it's not worth messing with the stock carb. I have a drawer with old carbs off stuff I bought or fixed that the China stuff replaced!

 

If it feels like it has to much compression, it could be the timing is to far advanced, I bought a Chinese coil on ebay that gave me that problem once or even a sheared key.

 

Chi niece coils are crap. I bought a Huztl one that lasted less than a year (Husky394).
I've read a lot if negative feedback about the carbs too, so for this guy, it's name brand. My saws are too valuable to skimp, and IMO you are doing just that with cheep ch eye neez parts.

 

I have had similar experiences with 2 small Huskies and it was ignition coils.

 

I did get this coil to work by slotting out the mounting holes with a dremel tool and turning the coil (counter clockwise if memory serves) on a 044.

 

And I get that. The problem is (with those shy neas part) they are very inconsistent. You may get one that lives fo looong time, I may get one that is total chit.


Can I get some kind of reward for spelling china-man-ese so many different ways, in one thread? Or am I the only won laughing?

 

H and LA and idle screw.

 

The LA is the idle screw, are you getting the L side screw confused with the idle screw? You will have two screws very close (side by side) will be the H and L screws, and one that is by itself (marked LA) is the idle screw. It is easy to assume the L screw is the idle screw because adjusting the L screw will change the air fuel mixture at idle, therefore adjusting idle rpm.

 

One thing I don't see mentioned is the non serviceable check valve that is pressed into some carbs. I do NOT know if this saw has one. It looks like a brass plug with a hole in the center. Carb cleaner WILL damage it. Test by pressing a square cut piece of fuel line against it and blowing and sucking. Used fuel line will add flavor. To many times it gets "rodded out" and suffers from chemical warfare.

 

I'll check that out thanks a lot