066 wont start

[Bweighmaster]

It'

Try turning in the idle speed screw a few turns and see if you can back it off until it'll idle. If a saw is being a bear to keep running I'll turn the idle screw in until the saw stays running, then I'll just back it off and adjust the L screw as needed until either the saw is idling or it kills itself. If it kills itself I'd start investigating other issues. If you can, try pressure testing your carb. It should hold a certain amount of psi indefinitely, if it doesn't you need to find where it's leaking from. I'd strongly recommend getting a Mityvac 8500 or something similar. Mine has saved me a lot of money and headaches since I got it.

It's about repairing instead of replacing

 

[TheRockyMountainKing]

Ok, heres a vid. You can see my finger moving, and it wrapped up, sparks shooting out exhast. Interesting.


Vid was too big to put on site so its on YT just copy paste link.

Ignore the drive sprocket flying off haha.

 

[Woodslasher]

If the saw bogs like that when you hit the throttle it's way, way, way too lean. If it throws sparks out of the muffler like that, it's probably eating itself. I would remove the limiters and fatten up/unscrew the L screw a turn or so and go from there. If you keep revving the saw like it sits you'll probably blow up your top end.

 

[Bweighmaster]

Have you cleaned exaust port ? Muffler ? Just askin .......

 

[Bweighmaster]

If the saw bogs like that when you hit the throttle it's way, way, way too lean. If it throws sparks out of the muffler like that, it's probably eating itself. I would remove the limiters and fatten up/unscrew the L screw a turn or so and go from there. If you keep revving the saw like it sits you'll probably blow up your top end.

Get a chain on it to see how it performs under load ....

 

[Woodslasher]

Get a chain on it to see how it performs under load ....

That's not going to help with the sparks or the excessively lean condition. Saws run even leaner (and hotter) when they are cutting so it would only make the problem worse.

 

[Brufab]

If the saw bogs like that when you hit the throttle it's way, way, way too lean. If it throws sparks out of the muffler like that, it's probably eating itself. I would remove the limiters and fatten up/unscrew the L screw a turn or so and go from there. If you keep revving the saw like it sits you'll probably blow up your top end.

 

[TheRockyMountainKing]

If the saw bogs like that when you hit the throttle it's way, way, way too lean. If it throws sparks out of the muffler like that, it's probably eating itself. I would remove the limiters and fatten up/unscrew the L screw a turn or so and go from there. If you keep revving the saw like it sits you'll probably blow up your top end.

I think i just need a new carb. But you saw how it popped/jerked, then started running?

 

[Mad Professor]

I think i just need a new carb. But you saw how it popped/jerked, then started running?

Are you sure it don't have electrical shorts? Checked wires to control switch and plug/coil wire?

 

[Bob Hedgecutter]

@TheRockyMountainKing - in my opinion, if you continue to try to run that saw as it is- you will have nothing left to run with in a very short period of time.
The sparks flying out are most likely small pieces of red hot metal being peeled out of the combustion chamber and will kill that saw very quickly.
Also in my opinion, you have bolted a fresh top end of dubious quality onto a worn out bottom end and very likely have issues with bearings and seals both sides and middle of the crank (nipping up and then releasing is a possible explanation for your jumps in hand analogy).
Stop trying to make it go- tear it back down, show us photos of the cylinder interior and the removed pistons outer. Rebuild the bottom end of the engine if it is economically viable (ruined bottom conrod big end bearing = new crank), probably at this stage clean up the original cylinder and order a Meteor piston set, do ALL seals and gaskets and then we can walk you through the rebuild process bolt by bolt and perhaps make a thread of 11 pages worth of viable information and not 11 pages of un full disclosure and keyboard ping pong.

 

[Woodslasher]

I think i just need a new carb. But you saw how it popped/jerked, then started running?

Yeah, if it's way lean it's going to almost die because it's not getting enough fuel, then once the H circuit kicks in it'll suddenly take off. Your L circuit provides about 80% of your overall fuel to the saw, so if it's too lean your saw is going to suffer. At this point I tend to agree with Bob, although I wouldn't plan on replacing the crank unless it's definitely roached.

 

[Sierra_rider]

I think i just need a new carb. But you saw how it popped/jerked, then started running?

At least back the carb screws out first. Those seem like rather lean settings...as others have said, 1 turn out is usually a good starting point.

You might also want to check the metering lever height inside the carb. It's possible you bumped it out of adjustment when you rebuilt it. I've even had a brand new OEM carb on one of my 044s that came with the lever way out of adjustment...no amount of fuel screw turning could make it run well until I bent it into spec.

If you at least get the carb settings squared away and it still runs better with the saw oriented a certain direction, that sounds like an air leak.

 

[TheRockyMountainKing]

At least back the carb screws out first. Those seem like rather lean settings...as others have said, 1 turn out is usually a good starting point.

You might also want to check the metering lever height inside the carb. It's possible you bumped it out of adjustment when you rebuilt it. I've even had a brand new OEM carb on one of my 044s that came with the lever way out of adjustment...no amount of fuel screw turning could make it run well until I bent it into spec.

If you at least get the carb settings squared away and it still runs better with the saw oriented a certain direction, that sounds like an air leak.

The inlet valve was dead on. The limiters got yanked out, screws set at 1 turn out, and thats what it sounded like.

 

[Woodslasher]

That saw is way leaner than it should be at one turn out, I'm gonna say it has an air leak.

 

[Bob Hedgecutter]

That saw is way leaner than it should be at one turn out, I'm gonna say it has an air leak.

I think air leak first got contemplated at least 10 pages ago.

 

[Brufab]

Those sparks are concerning to say the least. The 60 year old saws I run basically don't even have a muffler, and I never seen sparks.

 

[TheRockyMountainKing]

That saw is way leaner than it should be at one turn out, I'm gonna say it has an air leak.

I bet its an intake boot. I dont know what else it could be at this point. Unless i put the base gasket in wrong.

 

[TheRockyMountainKing]

Those sparks are concerning to say the least. The 60 year old saws I run basically don't even have a muffler, and I never seen sparks.

Im wondering if they are coming out of the muffler, not the cylinder.

 

[Bob Hedgecutter]

I bet its an intake boot. I dont know what else it could be at this point. Unless i put the base gasket in wrong.

Im wondering if they are coming out of the muffler, not the cylinder.

Yep, you can keep guessing.
Heck you can even zip tie the trigger at WOT start it and walk away- it might mysteriously fix itself- or burn down your workshop.
Keep tinkering with carb settings, keep running it and when it stops for good- pull it apart and find out for sure what was wrong where.

 

[singinwoodwackr]

Ok, heres a vid. You can see my finger moving, and it wrapped up, sparks shooting out exhast. Interesting.


Vid was too big to put on site so its on YT just copy paste link.

Ignore the drive sprocket flying off haha.

O…my…