Question on sprocket engaging while starting

[thompson1600]

I have a question for ya. I have an 036 here that is driving me nuts. I'm sure I've just looked it at for too long in the heat today but I can't figure it out.

With the saw off, I spin the chain on the bar. The chain will spin fine, but the crankshaft also spins. When you pull the starter rope, the chain spins. When I first change out the clutch and sprockets it acts normally (sprocket spins free with chain around bar for many rotations). Then suddenly it will "catch" and start turning the crankshaft over while I'm spinning the chain. It doesn't catch on every revolution like a bent crank, but just when it finally does "catch" it stays stuck.

I changed clutches twice and sprocket twice. (the clutch that originally came off this saw had the carrier broken in 3 places).

Saw was completely torn down, new bearings and new top end. Pressure/Vacuum tested out great, starts and runs fine as long you keep the throttle going (haven't really been able to adjust the carb from the rebuild so it's set to 1 turn out for L and H). Clutch drum bearing is new and looks fine.

The only thing I can think of now is the crankshaft being slightly bent. I checked it by eye and can't see any deviation when spinning it. Bearings fit in fine and aren't spinning in the case

What could be causing this?

Thanks

 

[HiOctane]

First thing first.Did you check or change springs ?did you check if the slots in the shoes or the "arms"holding the shoes are not worn or having a ridge ?How about the bearing and the sprocket surface where the bearing goes if not pitted or broken.The washer on the back of the clutch mounted backwards ?I dont think the crank is bent ,but remove the sprocket and use something like a screwdriver close to the end of the crank to see if it is straight while you pull the cord w/o the spark .The 036 has also 2 diff clutch assy models ,maybe you got the wrong one for your saw.

 

[fishhuntcutwood]

Off the top of my head, I'd look at the clutch basket (drum). Is it bent, or is there a burr in it that's catching on the clutch pads? How's the drum bearing? Is something lodged between the basket and pads? I'd assume not, as you say you've had it torn down all the way. Are the springs sound?

I'm sure someone will get on here and give you a definative answer, but this would be my thought. Especially since it's happening at hand turning speed, I'd look at that basket, and not think so much it's the springs.

Jeff

 

[thompson1600]

I didn't change the springs, I just changed out the whole clutch assembly. I do have two different "styles" or "looks" to the cluthes and tried using both.

I am not seeing or feeling anything that would be catching.

I'll have to check the washer (now that you mention that, I don't remember putting one on, that may be what I forgot! thanks)

I did try the screwdriver trick to see if the crank spun true, didn't see any wobble at all.

Thanks!