I changed the oil in my motors this weekend and the port side was light brown in color and had some white tinted goop under oil fill cap. boat has been sitting for about 4-5 months not started and last time i was there i changed the impellar. How concerned should i be? Should i run a little bit and check the oil? What is most likely cause? Has about 360 hrs had valve and lifters done on this motor last summer.

Pull the spark plugs and check for signs of water (rust) on plugs. I have seen a LOT of leaking headers.

Leaking headers. I would pull all your cmi headers and check them for leaks with a garden hose. might want to limit water pressure to 35 psi or so. I crapped out a 525sc with cmi headers a while back and had the same issues, brown oil and fudge ice cream in the valve train.

Some headers will only leak when they get hot. Since it is still early in the season I would send them back to CMI to get checked. If it is a leaky header and drops water when your engine is hot it will blow it.

I did the garden hose check and it passed, then blew my engine on the lake. Cheap insurance to have them check it.

my.02 cents

can headers be repaired or do you have to purchase new ones?

depends on the age and were the repair is needed.

tom is right. send it in to CMI and only CMI. i had a local stroke check mine and blew a motor. Said it was fine not the case.

Ditto on all of the above. Take the hint on the milky oil and figure it out before you have an engine failure.

It is leaking header. Pulled plug #7 and had rust then pulled headers and one side leaks. Had a leaking header on the other motor when i first bought the boat. Seems like way to many headers leak why dont someone solve this problem and if it blows enough motors would manufactur be liable?

Thanks for helping me diagnose problems.