Murray OHH60 surging

[djwdjw]

I am working on a 5 year old Murray with a OHH60 engine.

It would not start, but after cleaning the carb almost all appears fine and it seems to run well under power.

However, the governor seems to be commanding a continuing engine surge, about one vrooom per second at what is supposed to be idle. I can hold my finger on the butterfly and it will seem to idle without dying, but as soon I let it loose the surging starts.

All the springs seem to be right. What is the next step in resolving this? Is the governor stuck or something?

 

[Kenny_McCormic]

1. Mail a dead cat to the EPA, this is more than likely their fault.
2. You need to swap the carb for somehting with adjustable mixture.

 

[jr dragster T]

Yep that is lean as #@$% surge.

 

[djwdjw]

I am not sure I understand.

The governor seems to be blipping the throttle butterfly, but as far as lean goes, there does not seem to be a way to adjust anything in the carb unless there is an epa plug I have missed somewhere.

Any pointer as to how to resolve would be appreciated.

 

[kibble]

I had a similar problem to this, actually still sorta do, with my pressure washer. Turns out the problem is the EPA and one way to solve the issue is with what Kenny suggested. :arf: As Russ told me, he said it's a common problem with EPA carbs that have no adjustments.

The only way I was able to make it tolerable and somewhat useful was by cleaning the crap out of the carb and making sure that all the crud was gone, including the invisible stuff, iow, clean it til you can't clean it no mo'!

After cleaning it, I made sure that there were NO air gaps ANYWHERE on it, between the carb and the engine itself and the gaskets.

This was my issue:

http://www.youtube.com/watch?v=yftKh3x1Se4

 

[jr dragster T]

Ok this is the probelem. The probelem is in the dirty or lean carb. The engine is so lean that it wants to stall. The governers job is to open the carb when the engine RPM's drop. So basically the governer is trying to keep it going, Hence making it surge.

 

[Kenny_McCormic]

Most of em have plastis jets, open em up a FRACTION OF A HAIR with a hot pin.

 

[Russ2251]

Adding a small amount of fuel injector cleaner to fuel sometimes cures the surging problem.