G-8 Yamaha GP 396 sled motor swap

[chazdo2]

I have an old G-8 Yamaha and have a 1970's Yamaha GP 396 snowmobile engine. Going to start the build with all the info I have obtained from this great site! Just looking for any tips or pitfalls to watch out for if anybody has done a G-8 snowmobile engine swap. Any stiffer springs needed for the driven clutch if the stock Yamaha snowmobile clutch is used? Different than stock belt ? Any tips like that appreciated!!

[sho305]

They should both be 1 3/16 belts, you might end up with different length. If you want full power you need to install the pipe(s) for exhaust, you need to keep the length and diameter the same that tunes the pipe, you can put bends in it by cutting and re welding/etc. You could add a little to the head pipe near the engine if anything, that would tune it a little lower rpm. Use the sled clutch. The secondary might need some mods you will have to look at other threads here might have info on that. Some put a shorter spring in the primary so it takes off smoother at lower rpm. Some sled clutches engage harder and jerk, its in the tuning of the clutch. With a rolling cart initially it moves easier than a heavy track on a sled. The length determines engagement, the stiffness determines top shift rpm, for a primary not the secondary spring.

[chazdo2]

Thanks a ton as always!!!! My engine should be here soon!!!