Bad thermostat? Motor RPM Surging

[kenmyfam]

Re: Bad thermostat? Motor RPM Surging

Thanks for all the replies. I actually did just that, I removed the canister filter from the system and fed my fuel line directly into the pump and took it out on the lake for a test run. It ran great!

My cylinder head temperatures are running from 120-130 at all times.

Now, this engine has brand new pistons and rings, I'm in the process of breaking in the new engine. That being said, after I got home I pulled the plugs and each did look slightly different, varying from all black to a light brown. Are different spark plug colors normal for a new engine?

Post some photos of the plugs for us all to see and comment on. Really should all be similar though. (My humble opinion only though)

 

[sutor623]

Re: Bad thermostat? Motor RPM Surging

Thanks for all the replies. I actually did just that, I removed the canister filter from the system and fed my fuel line directly into the pump and took it out on the lake for a test run. It ran great!

Heck yea! Good call EMD!