My First Motorbike Project

GoldenMotor.com

5-7HEAVEN

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Aug 2, 2008
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gera, I see you're using T8F drive like me. I have the same 11t/72t combination, but with 5:1 gearbox. Your gear ratio is 19.64. My first and second gears are 46.4:1 and 38.2:1, respectively. final drives are 15:1 or 17.7:1.

Still fiddling with the engine clutch, huh? I used pocket bike clutches on my GP460 engines. They bolt right on, IF your engine has a tapered crank snout. I had to shave down the center mounting nut a bit. If running 460 clutch on pocket bike engine, ya might just have to install a washer under the center nut. Honda X50 might also use the same clutch as GP460.

Ya might want to consider using a more dependable engine. The only thing I had to do on my Tanaka 47R engine is adjust the carb and fiddle with the pull start. I have never had any clutch problems with the 47R, unlike my GP460 engine's appetite for clutch springs.

Have fun. That's the main thing.
 

gera229

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Sep 4, 2011
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I thought this thread was outdated by now. I guess not. You're using a shifter kit? Nice, nice. Seems funner and faster that way and easier on the engine during acceleration and faster for top end speed.

I don't use a GP460 engine.

I'm getting into road biking right now and bought myself a good deal.

I still have my motorized bike and don't know what to do with it. I think I may sell it and when I outgrow road bicycling, I might just do a quality motorized bike building again except with quality and a quality engine like the Tanaka. I like power so maybe a Morini if they still have them or similar haha.

I find the clutch problem becoming rather annoying. Having it break down in the middle of a trip where many cars pass by and you cannot pedal either just because the spring gets in between the plate and clutch housing. Having to open it up while it's hot and change springs just isn't all that wonderful. Not only that, but changing springs every 30 or so miles is rather costly.
Someone needs to invent a quality clutch for this same exact engine, one that doesn't snap springs. But I suspect a high price tag so it might not sell as well and might not be worth it.
 

5-7HEAVEN

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Aug 2, 2008
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I know you don't use the GP60. You have a pocketbike engine, but the GP clutch will bolt onto your engine IF yours has a tapered crank snout.

If you install a left-hand freewheel on the 72t sprocket, you'd be able to pedal with a broken clutch spring.
 

gera229

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I didn't know there were freewheels like that.

Other than that, I think my crank is tapered but I don't see why I would need a GP clutch.
 

5-7HEAVEN

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Aug 2, 2008
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I didn't know there were freewheels like that.

Other than that, I think my crank is tapered but I don't see why I would need a GP clutch.
"The problem:
Well I was revving it, and the mounting bolt in the middle (on the side where there are 3 bolts), just fell off. I expected it because that spot is stripped to the point that I can turn it by hand.
I would like to know if there are any solutions to repair this. I can make the thread bigger and use a larger bolt, but that will take some time. But if that's my only bet right now I will attempt it. If you guys have a solution for me please let me know."

Your own words last year.
 

gera229

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Hmm did you really read the entire thread again?

Also what does that have anything to do with the clutch?
It's just the mounting bolt threads on the engine being stripped which was long repaired by now.
 

gera229

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What do you mean? What does the mounting bolt have to do with the clutch?

But other than that, I don't really ride it much because I got into road biking but last time I did ride it, the clutch was fine. It's just it snaps springs at the most random occasion.
I think I made the springs last a little longer by following advice from the pocketbike forum and drilling holes in the clutch to keep it cooler and also drilling and sanding (with a small drill bit) the holes the clutch springs hook onto. That made it have smooth and round edges so I guess less wear on the clutch springs that way. Besides, from what I remember, the aluminum clutch doesn't snap springs as often as the steel clutch does.
 

5-7HEAVEN

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Aug 2, 2008
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If the crank snout's mounting nut is too thick, it will hit the center of the clutch drum.

Never mind. You don't have clutch problems any more.
 

gera229

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Oh I wasn't referring to the clutch to crank mount, I was referring to the engine mount at the bottom where 5 bolts hold it into place.

Other than that, I don't have any problems with the crank bolt and mounting at all. Crank is fine.