steppin up

[driver]

i have a 71 r60/5 i would like to put 750 jugs pistons and heads on from another moter i have. is the lower end of both moters the same? they are both 71s. also can i use the same carbs from the 60/5 or will i need to change carbs also. any input would be appreciated thanks.

[AnnapolisAirhead]

The camshaft is different on the 750. If you want all the bump up in power, you'd need to change that, but probably a lot more trouble than its worth.

The R75 came with Bing CV carbs that are 32mm at the intake side, so your heads spigot needs to be changed to a 32mm from the 26mm that the R60/5 has. Also, different carb throttle cables and the addition of a choke lever on the left side of the airbox (should be a white/translucent plug there now) and corresponding cables. Airtube between the airbox and the carbs need to be changed too.

So, if you are going to use heads from an R75, you might as well use the proper carbs: Bing 32mm. I looked into the same thing with my R60.

[mymindsok]

Yes, the R-60 cam is different but if yourer going to do the swap right, changing id over to the R-75 can really isnt that big a job.

Just watch out. Once you experience the raw power of the R-75, you'll want an R-90!