Topic: piston pin size

[Don R]

 This may be a silly question but what are the odds an old build 3mm stroker 750 with aluminum mtc rods has bigger piston pins? My guess is 17mm, I want to order a machined dowel to check for a bent rod.  Or am I wise to wait and measure them when it's finally back apart?

[754]

Waif till its apart. Probably 15mmbut you never know. If you have a lathe you cann make the pin easily.

[scottly]

Don, if you suspect the binding is caused by a bent rod, remove the cylinders. If the crank still binds, it's not a rod. I still suspect the welded crank is not quite straight, which is why it only binds in one place...

[754]

Dies nit a bent rod usually make a distinct wear pattern in the bore ?

[Don R]

 I need to just take it apart one bit at a time and put this matter to rest. I would also expect to have seen wear in the old bearings or cylinder walls if the crank or a rod were bent. 

[gschuld]

3mm stroker is very odd too.  Why weld up a crank for 3mm?  Or do you mean 6mm stroker crank(common) with 3mm shorter MTC rods to even out deck height?

MTC aluminum rods have plenty of meat to bore out to 17mm pins though.


George

[Don R]

 Probably 6, I lost my measurements.  I figured 1123 or 1124 cc. The PO's kids called it a 1200.