440 crank rpms

[red19lite]

some cranks press fit tighter than other,s high rpms don't like 50 to 1 mixes either I got a lot of burnt down xenoah,s cranks from high rpms extended run engine,s I now recommended 24 to 1 more oil less friction , high clutch engagements are hard on crank alinment also, you can get away with quite a bit of the high rpm for a time, every time a crank is taken apart and pressed back together the press fit loosen a little, the new rod kit for 77-78 xenoah have a tad tighter press fit than oringnal,s have a couple race motors with time on them and are holding up very well not welded, the center section of the xenoah cranks can be keyed and phased in for bullet proof index, a good balanced clutch is a must also , some of the old worn crankcase,s have lost the fit on the bearing o.d ,s in the case and lineboring is necessary you would be susprised at how easy a crank turns in a good fitting straight case but hod rodding and racing your going to have issues along the way the tohatsu crank there are different version,s you want 73 stuff its more reliable than early 440 fan cooled stuff,high temp press fit Loctite just about retires pin welding having better results with it now, just my two cents kevin

[dacota25d]

Thanks for the info Kevin. I never have and never will run 50:1 I usually run 32:1 in all my sleds even my fancy new sled Oil is cheaper then motors and I agree less friction=more power

[racingelvis]

more oil also means more cooling for the motor. in our race engines we always run 32:1. kevin, I have heard the Loctite is working real well in allot of applications.

[dankubista]

Hey bill, off topic.... is there any reason why injection oils can't be used as a premix? It says no way on the label but why would be the question? For my rider sleds I have always used the cat 50:1 injection Huile oil. I literally beat my sleds and 1000s of miles never had a motor lay down. That said, the premix oils seem to be limited to a lot of synthetics. I mixed klotz for the super brute, smells good, but is it really any good beyond the smell? Any true non synthetics out there for premix?