• Gy6 flywheel side crankshaft taper?

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 #12182  by Tundrawolf
 Wed May 02, 2018 10:43 pm
Hi guys,

I have a tomberlin crossfire 150 that I take my dogs for rides on, that is really anemic. I want to take it on camping trips and take the dogs around (can't on my quad).

Anyway I have a Honda gx620 engine I plan on mounting to the kart, and I want to use the flywheel side of the gy6 engine to power the kart for two reasons, 1. Use of the cvt transmission, and 2. Reverse gear!

I'll remove the con rod and piston from the motor to reduce drag, and just keep the oil in the crankcase.

My question is, what is the crankshaft taper on the flywheel side of the engine? Is it a common taper? If not, I have to use the flywheel to mount a flange, with a shaft so I can experiment with different pulleys as the gx620 turns 3 times slower than the gy6.

Unfortunately someone cut the shaft of the gx620 and welded on a pulley, so I have to experiment with the driven pulley sizes.

Any help is appreciated!
 #12183  by CheethaSpeed
 Wed May 02, 2018 11:37 pm
I can’t answer your direct question about the tapered shaft size. Sounds like a complicated solution especially since the cvt for a gy6 starts at 3000k rpm which is almost where there 620 stops. Seems like you could swap the crank shaft with used or new shaft more reliably than an odd custom solution. Plus the engine would have full value restored. Then you get a number of cvt options to suit any budget. If you haven’t seen my gx610-it is an area I’ve spent some time planning so I could help you more on a traditional route. Don’t copy red beard!!!! Otherwise you really should check out the 175cc build kit offered here. Efi is on they way. You can have reverse and all the engineering is done for you. Daily email deals are your best best for the best price (y) All custom is is going to end up costing more Money and time. I’m watching everyone else finish and ride so far... :?

My next build will be a gy6 for ease and Nano EFI
 #12204  by Sportsman850
 Thu May 03, 2018 10:35 pm
If you're set on going with the Honda, remove the 150cc howit. Use a reverse from eBay and mount it that way. Or use the howit and get reverse for that. Mixing the two is gonna be a pain, spendy, and space consuming.