1999 ox66 250 lean on top end?

[hank250]

Just put in new o2 sensor and replaced all fuel filters and all 3 low psi pumps. Vacuum checked after and everything looks good. Motor runs great , but when I look at the plugs after a run they are a very very light brown. Still seems a little lean to me. Anyone know for sure what they should look like when everything is OK.

Thanks Tom

 

[yamamarinetech40]

Re: 1999 ox66 250 lean on top end?

Why do you say 'still', was there a problem before? Light tan is normal but you should ALSO see some trace of oil or soot on outside of plug(should be able to get some black on fingers from plug). If not I would check and adjust the oil pump output a little...

 

[hank250]

Re: 1999 ox66 250 lean on top end?

I say still because before I replaced the low psi fuel pumps the plugs had no color to them at all. Could the oil strainer be in need of cleaning or replacement?
Thanks Tom