Pulled The Trigger On a Chinese 4-Stroke Belt Drive

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Not sure what is meant by bearing mod. I know BGF carries the parts
for the trans, including the bearing. I'd like to have a polyetheylene
bearing, tough and a slippery surface without lubricant. Maybe, I'll
have one made and try it out. CORRECTION: BGF carries the complete belt
trans and clutch but not the bushing.
Bearing Mod https://motorbicycling.com/threads/4g-t-drive-bearing-conversion.37410/

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Wow, I was blown away by this thread, modifying the shaft to receive a 13x20x4mm
sealed bearings (4), replacing the oilite bearing. What a terrific idea, just a little scary
trying it on a new engine. I saw two ideas: grinding down the shaft to receive the
bearing, or grinding the bell to receive a 15x21x4mm bearing. Any thoughts on
which would be better? I'm anxious to try this and get rid of the oilite problem.
 
I found a great source of these rubber sealed bearings at about $1.00/bearing
available from Fast Eddy Bearings packaged in 10 units for $9.99. They have
13x20x4mm (shave shaft) or 15x21x4mm (grind bell), here:
 
Wow, I was blown away by this thread, modifying the shaft to receive a 13x20x4mm
sealed bearings (4), replacing the oilite bearing. What a terrific idea, just a little scary
trying it on a new engine. I saw two ideas: grinding down the shaft to receive the
bearing, or grinding the bell to receive a 15x21x4mm bearing. Any thoughts on
which would be better? I'm anxious to try this and get rid of the oilite problem.
Great modification I would do it today if I had one of these engines

I would suggest to open up the clutch drum bearing hole instead of messing with the crank shaft.
For one, if ya mess it up the clutch drum can be replaced for cheep
I recommend taking the drum to a Machine shop and have them match the boar to the bearing. You'll want the bearings to have a good press fit
 
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I found a great source of these rubber sealed bearings at about $1.00/bearing
available from Fast Eddy Bearings packaged in 10 units for $9.99. They have
13x20x4mm (shave shaft) or 15x21x4mm (grind bell), here:
Fast Eddie might be selling cheep china bearings?

These come metal shielded 6702ZZ too not just rubber shields 6702RS Either one should be fine
I would recommend spending a few extra $ and buying the bearings from NTN a quality bearing Co.
 
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Thanks for the input. I'll look into NTN. You think metal shielded
would be better? This is exciting stuff!
 
Thanks for the input. I'll look into NTN. You think metal shielded
would be better? This is exciting stuff!
Metal shield are for dirty rough conditions or when chemicals will melt rubber
Rubber shield or metal shield will be fine for your application. They both should cost about the same
 
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Brand name bearings such as Nachi, NSK, SKS, NTN, INA, etc... can be expensive The 6702ZZ is about $8 to $10 a bearing.

While Fast Eddies 10 Pk for $10 might be OK? I would use VXB 10 Pk $35.37
I've bought many bearings from VXB over the last 15 years and they sell a good bearing



But I use Nachi bearings for my Whizzer M/B crankshaft bearings. (y) Nothing but the best
 
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