[gordy]

It just started today. I ran it for about an hour and now it surges up and down at a low idle rthymically. I cleaned the carb and checked to make sure all the wires were connected...
What should I check next?
Gordy

 

[mstngjoe]

How about PCV valve? Sometimes can cause irratic vacuum if it needs to be replaced ($3).

 

[camachinist]

How does the engine run otherwise?

Does it have good low-end power?

Have you tried plugging the PCV hose and noting any changes?

Still running a 2100 Autolite? If so, how far out are the idle mixture screws from bottomed?

Any smoking from tailpipe, particularly black? When warm, is the choke plate fully opened?

Get back to us...

 

[gordy]

runs well above idle

still has decent low end power

I haven't played with the pcv valve yet

I'll have to run motor til it get warmed up more to check the choke.

I'll just buy a pcv valve to start with.

Thanx.
Gordy