Poulan Pro 20" (4620AVX) fixing sticky throttle

[WalterWhite]

This relatively new saw has a problem with idle not dropping sufficiently. I removed the air cleaner cover and discovered that the throttle is not closing all the way when the trigger is released. I can reach in with a small screw driver and push it shut with a gentle push. It doesn't seem to be the throttle valve itself as I can open it by reaching in and pushing on a tab (on the disk attached to the throttle butterfly shaft) and it closes fully by itself. (That is, opening it without using the trigger.) The trigger itself seems to release fully too. There is a throttle cable connecting the trigger and disk on the end of the throttle butterfly shaft. I suspect that the cable is sticking or may be missing a return spring.

The previous owner (seller, actually) did O/H the carb to solve a problem with the power piston.

I thought I'd ask here for suggestions before I start taking it apart to figure out what's sticking and fix it.

thanks,
walt

 

[PonderousPiner]

Check curved guide

At the carb end of the throttle cable, there's a curved plastic guide. I would try cleaning/lubing this, as it's exposed to dirt. Are you sure the throttle linkage is assembled correctly?

PPine

 

[WalterWhite]

At the carb end of the throttle cable, there's a curved plastic guide. I would try cleaning/lubing this, as it's exposed to dirt. Are you sure the throttle linkage is assembled correctly?

PPine

Thanks for the tip. It's pretty new so I don't think it has had time to build up dirt and I suspected incorrect assembly as more likely.

However after using it a bit yesterday (felled my first tree!) it seems to be OK. I was able to adjust the idle speed down and that wouldn't happen if the throttle was hanging before it hit the stop. Perhaps saw vibration keeps it from sticking.

thanks,
walt

 

[KRP]

A little light oil on the throttle and choke shafts might do the trick. Sounds like it's running OK if you dropped a tree. Look at Madsen's Shop and Supply website for good saw tuning guide. You will probably need the carb tool to adjust the high and low needles. Open up the exhaust, premium fuel and oil, drop the bar size down to 18 or 16 with a pro chain, let her rip, and let the CAD begin.

 

[Fish]

I had a similar Poulan last week, The problem was the routing of the
throttle cable, it was rubbing on part of the carb, it was likely this way from the factory.

 

[knockbill]

you weren't in "breaking bad" were you????????????

 

[WalterWhite]

you weren't in "breaking bad" were you????????????

No!

Just a simple chemistry teacher doing his best to deal with his medical problem. :biggrinbounce2:

-walt

 

[knockbill]

great show, isn't it? i love black comedy........
by the way, i hope you got the saw sorted out........