Custom Rebuild, Many Questions....

GoldenMotor.com

vhatley

Member
Sep 1, 2010
33
1
6
Oklahoma City, Ok. 73118
Picked up a basket case yesterday, it was froze up and I expected to find a bad set of rings rusted to the cyl walls. Boy was I wrong. The Cyl looked pretty good, normal scarring etc., as did the rest of the upper end of the motor. :)
Here's where the fun began. When I tried to turn the crank/rod assy I could only manage to turn the crank about 1/3 rd of a turn. :( Inspection revealed a bunch of crap in the crankcase, which I went to washing out using gas/oil mix to begin with.
This morning I woke to a still froze crank...crap replace it, full rbld. I've rebuilt over 200 car motors in my life and realize this isn't a small project, but is doable. But I'm an automotive mechanic and need to find out a few things.

1. How to remove the clutch components on the outside of the crankcase in a manner to keep from losing anything or having springs suddenly explode from everywhere, so I need some diagrams on this...first.

2. When I rebuild, I personalize. I would like to know if there are .010 over ring sets available anywhere. I want to hone the cyl oversized. I may could hit the local mower shop with the piston and rings to see if other 2 cycle rings would work, but at this point IDK. I've also been looking into other mods I can make in the forum already, piston, timing, etc.

3. Specialty internals. I haven't shopped for parts for this deep before. Any help here would be greatly appreciated, I'm on a budget...I have a wife, the bikes just my favorite girl.

Sorry about the length of the post, but I'm trying to get as much as I can before she changes her mind. I intend on shooting for improvements in distance survivability rather than top speeds, though they do seem to go hand in hand! dance1

Thanks for all the help, I'll be posting pics of Bubba a little later, he's the intended recipient.auflg

Almost forgot, the motor is one of the Chinese affairs from BGF, or at least seems to be, 66cc.
 
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Tohri

New Member
Aug 28, 2010
159
0
0
People's Republik of Massachusetts
1: Dunno about pulling the clutch, I've never had to do it. should be easy/simple, haul the motor indoors and put it on a big table with a towel.

2: Boring these little monsters is a bad idea, there's no iron liner and the bore is chrome plated. But if you want to go whole hog, look at Foureasy's hybrid engine thread on this forum, and get a Puch top end. I've got a puch head on my china girl, and I'm going to be buying in a china bottom end soon to build up into a full motor with a puch massive port kit and Hi compression head.

Special parts that I've found make life a whole lot nicer are the High compression head on Treatland.TV, Engine sound dampeners, Nice controls,grips, etc, an expansion chamber exhaust, and hookworm 2.5" tires. The total custom motor I'm building will get a SBP shifter kit. Just tuning and porting your stock parts will give a huge boost to performance.
 

flatblack

New Member
May 22, 2011
374
1
0
Fairfax, VA
Not to hijack the thread but Tohri, Tell me more about this Puch head. I've read a little about it. Is it pretty much a straight bolt-on? PM me if ya want.

vhatley, there's not a lot out there in the way internals from what I've seen. Of course anything can be made for the right amount of $ or with the right knowledge! As Tohri stated, Foureasy seems to be the most advantageous in the way of custom motor building. For reliable power, save up and go with a Morini S6.