trailmaster 150 crank specs
 

Hey,
any of you trailmaster owners/ builders know the original manufacturer and dimensions of the crank (specs, measurements, etc)? I've been talking to a rep from Taida and they think they have a stroker crank that will work in the trailmaster 150 case. I gave her my engine type (JL1P57F) and she sent back two different types of gy6 crank they offer kits for. I know it's a long shot, but it'd be cool to be able to stroke this motor a bit. I understand that the crank in the JL1P57F motor is different than most gy6's.

Ok,
Bear with me here. This is probably old news to the folks that are experts on scooter and buggy motors, and I fully admit to being far from an expert in either. So, I guess before the GY6A there was a air cooled Honda motor called the KDU.. Now, Taida says they're similar but different, So lets take a look at the crank. Here we have your basic GY6 crank..

Here we have the trailmaster 150 crank.. Notice the step down on the right hand side of the shaft. The normal GY6 crank seems to slope down where the trailmaster crank has an abrupt stepdown..

Still with me? Good, here we go.. Taida said "Hey that motor doesn't use a KDU crank by any chance does it?" followed by pictures of the two different cranks. Here's the KDU crank. My TM crank has those same dimensions as the measurement in the pic, as well as the same stepdown on the shaft.

Here's one of the the cranks (GY6 and KDU) side by side. I have no idea what the numbers mean as there's a bit of a language barrier between me and the rep :)

So, could the Holy Grail of Trailmaster/Hammerhead upgrades be ordering a stroked KDU crank instead of a GY6? Discuss..

huh very interesting.

I'll be the ginnie pig and try this bad boy out. Putting together a 62mm BBK, Big valve 4V head, forged High Comp 4V piston, and stroke that sucker 8mm. BLAM!!!

wildbob, I highly recommend staying away from the 62mm bore!! And s 8mm stroke is huge! hope you have a serious battery with good cca, and some good power wire for it. Also might look into upgrading the starter clutch and maybe even the starter.

:evil:
in the side by side photo i notice the gy6 crank is tapered and the kdu cank steps down at a 90*.
the only issue there might be is the access plate behind the variator.
if i remember there is something to the spacing on the vari that is different from the ole skool gy6's. hard to remember from a hotel room in orlando, but you might want to check that out.

the trailmaster crank steps down too. looks just like the kdu..

Yup, high torque starter, clutch, etc, high flow oil pump and oil cooler too.. I made my own harness with thick gauge wiring.I know this baby will probably grenade, but I'm going to enjoy the hell out of it.. I have spare cases :)