I need to get some sealant to join my crankcase halves (RD350). I've read online and watched on YouTube that I should use a rubber based sealant? Anyone got any recommendations? Three bond has been mentioned but this appears to be silicone based? Standard off the shelf instant gasket isn't suitable?

Three bond and yammabond are what I'v always used never had a problem with either,rebuilt many a 350 with both.

Thanks for your reply. What number three bond do you use?

1104 threebond,on my wr250f I used permatex "the right stuff" instant gasket worked great.Makes any gasket in 1 min. as fast as you can assemble and put to use it seals amazing stuff.

Threebond 1104 is the same product as Yamabond # 4 which is what Yamaha recommends in they're service manual for the 350 YPVS for joining the crankcase halves.

Thanks guys for your replies. Threebond it is.

I use wellseal too, doesn't make a mess or squeeze goo into the cases.