Problem with my 064

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

moose42

ArboristSite Member
Joined
Jan 29, 2009
Messages
58
Reaction score
6
Location
Mad River, Ca
I now have an issue with my saw. It will idle after start-up and when I start running it and then release the trigger it is still in the throttle about half way. After five seconds it goes back down to idle most of the time. Or if it goes down to idle it takes the chain a few seconds to stop spinning like it is free spinning.

I did a muffler mod a while back and re-tuned and it went fine. Before the new symptoms started I did a mild port on it. I took off the lip on the intake as it goes into the cylinder. I made it wider a small bit. I squared up the exhaust port on the top part and then polished it. After I did that I re-tuned and tested it. It ran awesome. The next day I went to show my girlfriend how well it cut and It lost power when I was in the cut. Not when it first loaded up about a 1/3 into a 30" log it would. I figured out that it was the crank case tube that goes to the carb, it wasn't on. I hooked it back on and then it started to do what I mentioned above (but it has power once again). I rebuilt the carb and it still does the same thing. The only thing I could think of is the L mixture setting. I am just at a loss.

Sorry for such a long post but I figure more details the better. I will pick ya'lls brains to see if someone knows what is going on (or what I did wrong).
 
M 041 did the same thing wen the base gasket went. Sounds like an air leak to me.
 
Moose42

Check my sig for psi/vac testing.

Dan

I now have an issue with my saw. It will idle after start-up and when I start running it and then release the trigger it is still in the throttle about half way. After five seconds it goes back down to idle most of the time. Or if it goes down to idle it takes the chain a few seconds to stop spinning like it is free spinning.

I did a muffler mod a while back and re-tuned and it went fine. Before the new symptoms started I did a mild port on it. I took off the lip on the intake as it goes into the cylinder. I made it wider a small bit. I squared up the exhaust port on the top part and then polished it. After I did that I re-tuned and tested it. It ran awesome. The next day I went to show my girlfriend how well it cut and It lost power when I was in the cut. Not when it first loaded up about a 1/3 into a 30" log it would. I figured out that it was the crank case tube that goes to the carb, it wasn't on. I hooked it back on and then it started to do what I mentioned above (but it has power once again). I rebuilt the carb and it still does the same thing. The only thing I could think of is the L mixture setting. I am just at a loss.

Sorry for such a long post but I figure more details the better. I will pick ya'lls brains to see if someone knows what is going on (or what I did wrong).
 
I squared up the exhaust port on the top part and then polished it.

This is unrelated to your problem, but did you square the exhaust port at the muffler end or the piston end? From what I've read, I think it's fairly important to keep it oval on the piston side to reduce the chance of catching a ring in the port. I'm thinking you port matched to the muffler which is fine.

I've been thinking of porting my 346. I've read enough about it that I think I could do ok removing the base gasket and widening the ports along with raising them back to stock height.

Ian
 
This is unrelated to your problem, but did you square the exhaust port at the muffler end or the piston end? From what I've read, I think it's fairly important to keep it oval on the piston side to reduce the chance of catching a ring in the port. I'm thinking you port matched the muffler which is fine.

I've been thinking of porting my 346. I've read enough about it that I think I could do ok removing the base gasket and widening the ports along with raising them back to stock height.

Ian


+1 Ian. Just don't raise the exhaust at all. You want the torque and compression. You do not want a completely flat port roof unless you want to snag a ring.
 
I'd be pulling the muffler cover and taking a look. If that looks ok, then it sounds like it's running lean and then running on after you pull it out of the cut.

The piston looks fine and there is no scoring at all. Yes the saw is running on after the cut. I think I will replace the cylinder gasket like stevejr33 sugested. See if that will do the trick.
 
I start my tune at 1 and 1. I didn't have to change it much. It will do everything right at first then it will start acting like it is way out of adjustment, few seconds later it idles fine. It has no problem reving up. It cuts just fine, if it isn't an air leak then I have no clue what it is (I ain't positive it is). I ordered a new gasket and I may do a vac test.
 
Rebuilt the carb the other day runs the same way. I haven't noticed any linkage sticking or anything. I didn't back out the mixture screws when I did it. I didn't want to pull a pin out or anything and make it stay wide open (I have done that on my 4 stroke dirt bike).
 

Latest posts

Back
Top