Farmertec MS250 cylinder/piston problem

[AgTech4020]

Let me start out by saying I am not a fan of the Farmertec homeowner or rather clamshell engine parts. With that said I have ended up with a handful of MS 210 through MS 250 chainsaws that the engines are junk in. I only give about $25 for the complete saws. I then put a $30 Farmertec engine in them and that put them on a local auction sale. Recently the last two engines have been very doggy. I run all of them for a couple tanks of fuel to make sure they are semi-broken in and tuned properly. Both started out with around 120 pounds of compression cold before break in and have ended at about 135 cold two tanks later. For a Farmertec clamshell engine that’s good compression as far as I’m concerned. The problem I’m having is they are slow to accelerate and under powered in the cut. They pressure and VAC test perfectly. Cylinders look great after break in with no signs of streaking at all. In both cases they are OEM carburetors, intakes, fuel lines, and mufflers. Spark arrestor screens are clean as a whistle. I’m guessing it is a port timing issue just wondering if anybody else has sen this?


Sent from my iPhone using Tapatalk

 

[Jasonrkba]

I put one on my 025 and have been pretty happy considering how inexpensive it was.

 

[AgTech4020]

I put one on my 025 and have been pretty happy considering how inexpensive it was.

My first two MS250 kits really weren’t bad. Actually had one of them make 140 pounds of compression after about four tanks of fuel. In the big homeowner sauce I simply order their MS390 kit and put pop-up pistons in them. I’m just really disappointed with the last two 250 kits. They aren’t totally gutless they just have a very slow throttle response and feel weaker than they should. I think I’m going to try advancing the timing a little bit unless somebody has any other suggestions?


Sent from my iPad using Tapatalk

 

[Huskybill]

Slow bringing up the rpm could be the timing is too far retarded. Is the carb too rich on the bottom? Has anyone checked these new Chinese cylinders for being out of round yet?

I purchased the farmtech 372xp engine to pop in my 372xp saw.


What mix ratio are you using for break in? There’s been talk about these u build kit saws seizing up. The instructions say 20:1 ratio. I use extra oil, the oil bottle says 2.5 gallons of gas to one can of oil. (40:1) I mix it 2.3 gallons of gas to the same bottle of two stroke oil.

 

[cuinrearview]

This is precisely the issue with the China parts. Absolutely no consistency. The port timing is probably **** to go along with the **** squish height on the last two. It's like taking a seat at the Chinese chainsaw casino. Sorry to hear you busted this time around.

 

[computeruser]

Do the auction buyers know it’s a ChiCom rebuild?

 

[Huskybill]

Do the auction buyers know it’s a ChiCom rebuild?

My new 372xp engine I purchased from huztl. I have keyed flywheel too. The rest should be an easy swap. I figure it’s a fair test to break it in and push it. That will give me time to port the husky 372xp.

What’s my saw? Who cloned this saw? New show coming out soon. Lol no really can you tell the difference between a real husky 372xp and the huztl 372xp if we put on the orginal husky decals? The chain saw guy is selling a Chinese 372xp but he tells us.

 

[AgTech4020]

I only run 40 to 1 mixed premium gas with Stihl synthetic oil and tend to tune a bit fat during break in. I have tried leaning them out a bit more than normal for testing but I don’t gain much. I think I’m going to try advancing the timing a bit to see if it helps.

Unfortunately the China rebuild is the only practical rebuild for small homeowner saws. Most are straight gassed or have failed the crank bearings thus wiping out the entire engine. Oddly the homeowner saws are the best looking saws I get in. It always seems like they are just mechanically tough.

I only send them to the local auction house if they perform as they should and run perfectly. I don’t advertise them as rebuilt only as “Fully functional”. I don’t feel too bad as they typically bring less than a new Wild Thing.


Sent from my iPad using Tapatalk

 

[Huskybill]

This is precisely the issue with the China parts. Absolutely no consistency. The port timing is probably **** to go along with the **** squish height on the last two. It's like taking a seat at the Chinese chainsaw casino. Sorry to hear you busted this time around.

How about the guy on you tube building these Chinese 372xp saws. Seems like the squish seems to be the biggest problem. I don’t understand why the Chinese can’t machine the squish on the money. We’re only talking .001” here not ten’s of a thousand. They have CNC machines. It’s either machine it closer and use a laminated base gasket we can peel to the correct squish. We used the laminated gaskets in the 155 mm gear boxes to adjust the gear backlash. It’s simple and quick.

Btw, over 25 years ago I gave my son a new wild thing. His first job he cut a pile of over grown brush the size of a small ranch house, the first week. He feeds it left over 32:1 maxima super m dirtbike gas. It’s still running today. My point is keep the air filter clean and use a quality pre mix oil. I was shocked this saw is still running. When he started cleaning up my land in vt I handed him a new husky 460 rancher.

 

[Huskybill]

I only run 40 to 1 mixed premium gas with Stihl synthetic oil and tend to tune a bit fat during break in. I have tried leaning them out a bit more than normal for testing but I don’t gain much. I think I’m going to try advancing the timing a bit to see if it helps.

Unfortunately the China rebuild is the only practical rebuild for small homeowner saws. Most are straight gassed or have failed the crank bearings thus wiping out the entire engine. Oddly the homeowner saws are the best looking saws I get in. It always seems like they are just mechanically tough.

I only send them to the local auction house if they perform as they should and run perfectly. I don’t advertise them as rebuilt only as “Fully functional”. I don’t feel too bad as they typically bring less than a new Wild Thing.


Sent from my iPad using Tapatalk

I think Buckin Billy Ray on you tube is running a Chinese 372xp.

 

[AgTech4020]

It has always been the clamshell engines I have had issues with. Seems like the clamshells always have poor squish. I will be honest I don’t use many Farmertec engine parts in my pro saw builds (generally prefer eBay OEM or used OEM from members here). I’ve only built one complete MS660 kit saw for my own personal use and it had excellent squish numbers and has been a ton of fun.


Sent from my iPad using Tapatalk

 

[Jasonrkba]

I rebuild my vintage stuff with oem parts but my beaters get what I can afford at the moment. I just clean up around the farm and cut firewood with them.