Calling the China Girl crankshaft experts

[eclectic cowboy]

Hello all, been gleaning information off this site for a couple years now and have always been able to find the information needed, until now. I'm sure it's been discussed as it is rather run of the mill, but I am pressing one of my cranks back together and have no idea how much clearance the big rod end takes. Seems to me (that's never gotten me in trouble before!) That for reassembly that would be the first thing to deal with. Then shim the end play on the crank if necessary. Since I have yet to run into a Chilton's manual for Happy Time racing motors, I figured I'd ask the guys over here that are writing the book on these things.

Thanks in advance


Steve

 

[GW's Motorized]

It would be hilarious if someone made a manual for these and made it to resemble a Chilton manual.

 

[DieselTech]

@Street Ryderz is the OG crankshaft Expert!!!

 

[DAMIEN1307]

@Street Ryderz is the OG crankshaft Expert!!!

@ImpulseRocket is not too shabby either Diesel...lol...He knows what he is doing with crank seals, crankshafts etc.

 

[GW's Motorized]

@ImpulseRocket is not too shabby either Diesel...lol...He knows what he is doing with crank seals crankshafts etc...lol.

Me, im just along for the ride

 

[Wrench]

IDK but I would figure ya wouldn't want no more than .020" side to side play on the con rod and .006" crank end play
I've heard that the con rod can have as much as 1mm of side to side play and the Crank end play can be as much as 1mm
So now's the time to put some shims where needed

 

[DieselTech]

@ImpulseRocket is not too shabby either Diesel...lol...He knows what he is doing with crank seals, crankshafts etc.

Lmao that's why I mentioned OG crankshaft Expert. I think ImpulseRocket is right up there with him. I just failed to mention him.

 

[Chainlube]

The rod is 10mm thick and .3mm each side.

 

[eclectic cowboy]

Boy, you guys are Johnny on it. I didn't expect more than maybe one reply by the time I road the gas sipper back from my shop! I really appreciate it, even just having a clue about the con rod end slap. I'm a self proclaimed (taught) antique tractor and implement mechanic but the only motorcycle I have tore down is my Dnepr and it's got traditional slippers in it just like a Ford or Chevy. I have ran the snot out of slipper rods with two or three times the manufacturers clearance spec without incident but when there are no manufacturer specs I figured I should get with someone who knows a thing or two about two strokes and needle bearings.

Oh, and the self taught thing is a lie. 99.9% of everything I know I gleaned from someone else, now that I think about it!

 

[Wrench]

The rod is 10mm thick and .3mm each side.

OK .3mm = .012" each side = .022" side to side

Me saying side to side .020" = .010" each side, My logic was close