Buddy motor build - need advice

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Johnnyhatchback
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Buddy motor build - need advice

Post by Johnnyhatchback »

Background: got a donor buddy from a guy that help out with his buddy's, i'm basically his mechanic at this point. He blew (and i mean BLEW) the motor on a buddy 125. I have a Honda Ruckus, so i bought the bike off of him and i am going to rebuild the motor. It's currently completely disassembled. Because it was SO blown, i will be replacing everything on the internals. Crank, jug, piston, head, etc.

SO...

Considering that this is all being replaced, my assumption is that gy6 150 parts that are more or less "universal" will work with the exception of the kickstarter on the crank (which i dont particularly care about).

So the advice that i'm looking for is 1) does my logic with using gy6 parts seem sound? and 2) anyone's experience with using aftermarket engine internal parts that they have had good experiences with starting with the crank?
RiderK
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Post by RiderK »

While I'm not extensively experienced in the "GY6" group of motors I am aware that there is a gigantic variance of parts for these engines. I'd assume that people here have found winning combinations for these bikes but be warned that the vast number of variations of parts that "should" work may not work properly for your application.
2014 Roughhouse, S6 Sp Pro Mk2, C16 city, Athena full circle, 19 PHBG, Voca cf reeds, S6 TC clutch red spr, Polini vario, NCY tq drvr, premix, Polini tach temp voltage gauge, LEDs all around
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babblefish
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Post by babblefish »

I've replaced almost everything on the engine from my Blur and you're right about aftermarket cranks not having kickstart capability for the PGO style GY6. I modified my Dr Pulley variator plate to keep the kickstarter on my Blur though.

All of the aftermarket parts I've bought fit the cases fine: stroker crank, piston/cylinder, head, cam, intake manifold, HD oil pump, variator, clutch, etc. The only thing I found that didn't work was aftermarket crankcase gaskets. Most of them didn't match up with the PGO case so I bought OEM gaskets.

I machined out the crankcase myself in order to fit a 61mm BBK.

About the only thing that I can think of to look out for is that the oil supply port on the crankcase lines up with the one on the aftermarket cylinder.

Also, if you're going to get a significantly longer stroker crank, make sure you get a matching spacer for the cylinder and a longer timing chain. If it's a 6mm+ longer stroke, then longer cylinder studs will also be required.

Good luck on your build. A properly setup GY6 can make some fun power.
Some people can break a crowbar in a sandbox.
Johnnyhatchback
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Post by Johnnyhatchback »

babblefish wrote:I've replaced almost everything on the engine from my Blur and you're right about aftermarket cranks not having kickstart capability for the PGO style GY6. I modified my Dr Pulley variator plate to keep the kickstarter on my Blur though.

All of the aftermarket parts I've bought fit the cases fine: stroker crank, piston/cylinder, head, cam, intake manifold, HD oil pump, variator, clutch, etc. The only thing I found that didn't work was aftermarket crankcase gaskets. Most of them didn't match up with the PGO case so I bought OEM gaskets.

I machined out the crankcase myself in order to fit a 61mm BBK.

About the only thing that I can think of to look out for is that the oil supply port on the crankcase lines up with the one on the aftermarket cylinder.

Also, if you're going to get a significantly longer stroker crank, make sure you get a matching spacer for the cylinder and a longer timing chain. If it's a 6mm+ longer stroke, then longer cylinder studs will also be required.

Good luck on your build. A properly setup GY6 can make some fun power.
This is great info. Thank you so much.
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