Powroll 350CC Modification

Cap'n Dave · Post by **Cap'n Dave** » Mon May 05, 2014 1:01 pm

Anybody out there ever tried the out-of-production Powroll Kit that upped the displacement to 350CC ?

Also, has any one heard of a modified 5-speed transmission for the CB77 ?

mike in idaho · Post by **mike in idaho** » Mon May 05, 2014 6:34 pm

I had Webco kit in a CL77, along with a set of Harmon& Collins roller cams, back in the day. Had to bore the cylinder block to install the bigger liners. There was a tiny hole in the sleeve, below the ring travel for increased cylinder oiling, one had to drill through the oil galley on the front of the cylinder to reach it, then reseal the outside of the block with a machine screw. There was a five speed transmission around then, never saw one in person, it may have been a road race only piece (without a kick starter provision).
It was easy spot a 350 kit in a CL72, the cylinder block was cast a little bit smaller than the 305, you could see the cylinder liners exposed between the fins here and there.

Vince Lupo · Post by **Vince Lupo** » Tue May 06, 2014 1:00 am

If you do a search on the forum, you'll come up with answers to 350 kits as well as 5-speed transmissions.

I have both a 358 kit (Bore Tech) and a NOVA 5 speed in my SuperHawk. THe 5 speed transmission requires the elimination of the kick start assembly, and it costs about $2700 in change. http://www.novaracing.co.uk/ If you check out my thread 'Japan Meets Britain' in the 'Racers/Choppers/Customs' section, you can get more info.

Guess it depends on how much money you want to throw at the bike and what you're trying to accomplish. Might be cheaper (and less of a headache) to just go buy a CB350.

G-Man · Post by **G-Man** » Thu May 08, 2014 3:50 pm

Mike

Interesting about the oil drillings. My 1961 CB72 project has two little blanking screws in the oil gallery. I wonder if I'll find a big bore kit in there?

Thanks for the info.

G