Another pioneer farmsaw with problems

[wildcat99s]

Hello. So i've had my farmsaw for close to 8 years and it ran perfectly up until the fall 2018 before when i cracked a head and damaged a piston from the head bolts loosening from vibration while cutting. I replaced the head and installed a new piston and rings last year, I got it to start and it ran like crap and then the coil stopped working, ordered a new coil, installed it and it still ran like crap, and then recoil spring broke...I got upset, and then the saw sat for a year up until earlier this week. I replaced the recoil spring and it still runs like crap. so far I've rebuilt the carb, replaced the larger welch plug because it was loose, replaced the fuel lines, adjusted the low and high mixture screws every which way, pressure tested the case for leaks, cleaned the muffler, i've adjusted with the metering lever and got it running better than it was, but it's still very rough. I'd say that's its running rich because it's smoking a lot.

So Question: Is it possible that the new head/piston and rings are creating high vacuum and causing it to suck in more gas than it should? I'm thinking that because it has some massive compression now. I can barely turn it over by hand without hitting the decompression valve and imagine that the vacuum has been greatly increased as well. So I'm gonna open up the carb again and adjust the metering lever a little lower than specs to see if it'll make a difference. But i'm starting to run out of ideas on what else it could be? So any input would be greatly appreciated

 

[HarleyT]

Doesn't the compression release work?

 

[johninky]

You sure this is a Farmsaw? I have 2 and neither has an exposed decompression whatever.

 

[wildcat99s]

Yes, the decompression valve works fine. I was referring to trying to turn it over by hand without pull rope side of the engine removed, when i put the cover on, the decompression works as it should. And it'll start right up and idle, but acceleration and WOT is very rough no matter what i have done. I can adjust the screws down until it leans out and dies, and can richen it until it's super rough and dies. But there is no sweet spot like there should be.

There was only about a week time frame from when it ran perfect, replaced the head/piston/rings and then immediately it ran like crap.... which surprised me. But before i had it tuned and working for it being really broke in. and haven't been able to retune it for the new parts.

 

[wildcat99s]

So tonight I reset the metering level to where it should be. Level with the inner base. Before I just eyeballed it and was a little tall. Started it up but had no noticable improvement.

I'm gonna try again tomorrow. If I can't get it by Sunday I'll probably shoot a video so someone can see and hear what's it's doing

 

[rupedoggy]

Have you checked the reeds?

 

[wildcat99s]

Have you checked the reeds?

Not recently. I'll check that tomorrow

 

[wildcat99s]

how would i go about testing the reeds to make sure they work correctly? i inspected the reed and housing when i replaced the head and piston last year and didn't remember seeing anything wrong, as far as cracks or physical damage.... but as for the reed itself i remember it being not perfectly flat against the housing.... like the reed had a slight inwards curve from it being sucked in. But i assumed with the piston moving and some slight back pressure it would seal, but i could be wrong with that assumption. But the reed is about the only thing i haven't recently checked.

 

[wildcat99s]

Just for the fun of it, i found and ordered a new reed for it, but it's not gonna be here until later in the week. But i'm still gonna inspect it later today.

 

[rocketnorton]

cracked intake block?

 

[wildcat99s]

cracked intake block?

No. I've already did a pressure test and it's tight

 

[Old2stroke]

In a good reed assembly, the reeds will lay absolutely flat against the holder, shine a light in and should see NO gap. First sign of a reed valve not closing properly is spit back from the mouth of the carb.

 

[farmguywithasaw]

cracked intake block?

I have 3 like that and have seen a 4th recently

 

[rocketnorton]

got 3 here myself

 

[wildcat99s]

So yesterday I checked the Reed and it's sealed now. There was some wear on the lip that the reed seals on and I flattened and fixed it.

I double checked the pressure test and did a vacuum test. It'll hold pressure but on vacuum i thought I had a very small leak but turns out it was just the decompression valve leaking about 1psi every 30 sec. But if I manually pull the valve to seal it seems to hold vacuum fine.

Today it started but was jeering really bad. Like a bucking bronco every second or two like it's missing

Thanks

 

[wildcat99s]

What about back pressure in the muffler? A long time ago I had to replace the screen in the muffler with non oem quality. It worked then. But maybe I need finer screen to get more back pressure?

 

[farmguywithasaw]

What about back pressure in the muffler? A long time ago I had to replace the screen in the muffler with non oem quality. It worked then. But maybe I need finer screen to get more back pressure?

Nah it should run fine without
The screen

 

[Manic84]

With that erratic idle, blowing smoke and poor WOT, it's kinda starting to sound like a failing check valve.
But just out of curiosity, when you replaced the coil, did you use an OEM/NOS or an aftermarket one?
That video of it running would help cut the guess work down some.

 

[Madsaw]

Smoking? Like to much oil or over fueling? Could be possible window leaking between the tanks

 

[Manic84]

Smoking? Like to much oil or over fueling? Could be possible window leaking between the tanks

I had forgotten about that. Epoxy would be a quick stable fix for that.