So I have been tirelessly working on my f2 for the past 4 months to get it finished (basically replacing everything minus engine and frame) and im all done but found one problem. I changed the oil and filter and when I fired it up the let it warm up I noticed a drop of oil forming on the bolt right below the oil filter that holds the oil cooler on. So I assume that its the o-rings in the cooler that have gone bad. I replaced the 2 that go on the collars that are inside the block but forgot about the other two on the collar. Could this be the cause of the oil leak. Ive also noticed that the coolant is mixing in the oil, which is another reason I thought it was the o-rings. Im praying its not a head gasket. Any advise or help?

 

I think that you're right on the money with the "O" rings going bad. Remember they're 17 or so years old. Left undisturbed, they would have probably lasted a while longer. If you took the oil cooler apart, anyplace that there was an "O" ring, it should have been replaced. As for the coolant and oil mixing, yes, it's highly possible that "O" rings are the cause. Because coolant is used to cool the oil in a heat exchanger type of process, it's easy for the two to mix. Are you finding oil in your coolant, or coolant in your oil ?. I would suggest replacing all of the "O" rings.

 

yea... usually when you have oil in ur coolant... the oil cooler or the waterpump is the cause...

 

i havent noticed any oil in the coolant. just coolant in the oil. the bike had been sitting for acouple of years torn apart outside so im hoping that the o rings are just worn out. im gonna buy the other ones on bikebandit and just replace them and hope for the best.

 

Coolant in oil is almost certainly the inner o-rings sealing the oil from the antifreeze inside the heat exchanger. Head gasket is of course always possible, but it's also cheap and easy... though not as cheap and easy as o-rings on the heat exchanger.

I'm hoping it wasn't run like that at all, or you will have an exact repeat of my story, which was a super-exciting complete destruction of the bottom end of my motor, after having been lubricated by coolant.

 

Did you rebuild after that happened or did you just buy a new engine? Mine seems to run fine othe than the leak. I have noticed what looks like an oil stain on the side of the block around the oil cooler which has me alittle worried that there may be a hairline crack in the block.

 

well like i observed before and i told one guyon here before... these bikes are kinda wierd

Oil in coolant can mean water pump/oil cooler o-ring break.

Coolant in oil can mean head gasket...

I dont understand it my self but thats what it has proven, at least to me. It wouldnt hurt to check both tho

 

well the fact that the leak seems to be localized around the oil cooler makes me think its the orings. maybe its just me being optimistic. if it turns out to be the head gasket i might try to find another motor in case there is some deeper issues that can come with blown h.g.

 

"Did you rebuild after that happened or did you just buy a new engine? Mine seems to run fine othe than the leak. I have noticed what looks like an oil stain on the side of the block around the oil cooler which has me alittle worried that there may be a hairline crack in the block."

I rebuilt it cases-up, and am cruising it around with great success. I needed a new crank, all new connecting rods, a new piston w/ all rings, a new oil pump, and all new bottom end bearings. The build took me a weekend thereabouts. The engines are astoundingly simple. I was confused by how few parts I had when I was done taking it apart.

Oil stain near the cooler is even more of a clue the o-rings are no longer serviceable. Given the quality of the castings (having handled them for quite some time myself) I'd put that pretty low on the list of possibilities. Though... I guess I never expected my situation either...

 

i would like to rebuild one from the ground up just to get in there and really see the inner workings of these motors. ive heard they are fairly bulletproof which is an awesome thing.