Hi All,
Currently rebuilding my 1987 cbr1000fh engine, which I only stripped for a minor oil leak, but have ended up getting the head and the barrels skimmed, and replacing two inlet valves. In the past I have rebuild car engines and just oiled everything as it goes back together and then wound the engine over by hand for a few minutes before starting, (plugs out), to get oil through the system and up to the top end. However, I see a lot of guys using assembly paste around the cams and top end which I thought looks a great idea... Looking into this, it seems not everybody is so impressed, questioning if it does disolve into the oil fully when warmed through, (on piston heads forum, looking through threads, a couple of guys talked about it ending up around the suction filter). Also, many of these pastes contain a Moly additive, which I'm thinking around the bike clutch wouldn't be good?
I also notice there seems to be a number of manufacturers of assembly paste in the US, but only a couple here in the UK...
Anyone got any thoughts/advice?
Many thanks

 

The amount of moly that would get into the oil from the paste is negligible.

Either oil or paste is acceptable in my book. I would only use a small amount of paste on the cam journals or crankshaft bearings if the were new or if the motor was going to sit in storage before putting it into service. I wouldn't think twice about using oil and priming the pump on parts that have been run before. What would be the difference between that and starting it and riding it on the weekend? Nobody thinks twice about how much lube is on them for the years that it's being used.

 

Good points, thanks for the input!

 

FWIW I used assembly lube on the bearing surfaces - my rationale was that it was recommended by the service manual, and since you can't prime the oil pump without starting the engine, I liked having the extra protection. I didn't have any trouble with the clutch or anything

Break-in oil has a shortened interval and I changed it at 1000kms. It didn't seem crazy thick or anything so I don't think it affected the oil very much

 

What I have done in the past after a rebuild is, thin layer of grease on bearings and oil on the cam. Then pull the plugs and crank it over to get oil flowing in the pump and engine. I haven't had any problems doing that.

 

Thanks for the replies. I think I'll go with a thin smear of assembly grease on mains and cam journals, and prime up by hand before starting, thanks!
All parts have now arrived and valves lapped in ready, so all systems go!