Any BigBore/Rephase kits for 1972 306 engines?

256 and 306 are interchangable. There used to be 707 and 750 kits on ebay, but they have all dried up in the past couple of years. You can always change internals to 447 parts and do the 750 kit that way.
 
SteelToeJoe said:
Really? So what all internals are we talkin about, just conecting rods and crank?
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rods, crank, pistons, cam sprockets and chain(cams will fit both but gears have to be changed). i think that is it to use a 750 kit
 
Last edited:
can rephase a 256 WITHOUT swapping all the internals.
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Do tell! This after I went out and aquired late model engines for cranks and stuff. I have an early engine with the compression release. Can you rephase this? I don't care about the bigbore.
 
plane_ben said:
Do tell! This after I went out and aquired late model engines for cranks and stuff. I have an early engine with the compression release. Can you rephase this? I don't care about the bigbore.
Click to expand...

Yes I can, I just finished building a 256 with all stock internals this week :thumbsup: More details to come as the owner gets it alive and running :D
 
Used early model high compression pistons (with the large pin and lower deck height) and machined bushints and a 1/4" spacer for under the jugs. That motor is in ice racer and is a complete monster! I can run and beat 450s without hardly breaking a sweat
 
It was a listing that you already posted in, and the reply was that it had already been sold.
 
I know I'm resurrecting and old thread but I just dismount a 1972 engine today. The guy that sold me the bike told me that it had a 750 engine kit in it but finally, I measure the pistons and they are 75mm pistons so the engine is stock. I like the idea of the 700cc kit but is there someone who install one here ? What is the diameter of these pistons ? I guess that the cylinder block will need some machining too. What gain should I expect from a 700cc kit ? Thanks !
 

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