Hi! All gurus of 305's. I'm building a CL305 but into a custom race bike, And I have a CB motor for spare parts.
My first question is there any difference between the CB and CL cams and tranny?
And what can I do to take off some spinning mass off engine?
Any help will be appreciated.
Thank you!
Vlad
Need help on how to lighten spinning mass on 305?Read thru the "Race Bike Only" thread, particularly Jerry's comments on page 6 about lightening pistons, that's reciprocating weight which really adds up quick.
You can remove the cam sprocket advancer weights and weld up the advancer to full advance removing a little rotating weight, that along with Davomoto's suggestions will definitely help. Do a search for Vince Lupo's thread about his 350 kitted 5 speed bike he built up over a period of time and documented really well here, it sounds like an awesome bike. There's some magic that can be worked to the oil filter spinner inside the left engine side case but I don't know enough about it to suggest anything specifically. Remember there's a direct relationship between the ratio of money to speed to reliability. Are you building a race bike or a cafe racer type bike?
For a race bike, you need to start with the rules for the club you want to race with and then work out what is possible and practical within those rules. For example AHRMA allows 350cc plus .060" and there are a couple of commercially available pistons that will work there. Based on that bore, what valve and port and carb sizes need to be decided and then suitable carbs and exhausts. CB77 frames handle like a wet noodle when pushed and swingarms flex, shocks are useless and forks leave lot to be desired. Chassis improvements are probably more important that motor in terms of lap times and safety. The best race chassis you could buy would be from Jerry, but if the budget is modest, think about how to brace the frame forks and swingarm effectively and then upgrade the front brake. Lightening parts helps the motor to rev higher, but at least for a first season of racing that probably isn't the highest on your priority list. When those cranks turn more than "x" rpm, rings flutter and cranks fail, so high revs are not your friend. I thinking more like cafe racer bike.
I have CL frame and motor with 0.60 over. Thank you for chassis reinforcement advice. I may not go to crazy on motor just bore, carbs and same good ported head. Kind a lot of ideas. Thank you guys! and sorry for bad stalling, I'm bate in Russian than in English))) writing! If that were my bike, I would increase compression, add a mild cam and mild porting. I might lighten the rockers (because you can). I'd keep the stock alternator and wouldn't bother about trying to change the reciprocating weight.
I'd fit a valve spring kit and a set of CB750 carbs. CB750 had the same diameter slides but they are taller, so it's the same size carb at small throttle openings and a bigger carb when you open it wide open(they are oval bores). On the chassis for a street bike, I'd brace the rear frame tubes to the main spine and brace the swingarm. Wheels and brakes and tires obviously have to be spot on. Forks I would prefer to replace with a pair of 35/36mm from almost any other bike and fit a fork brace.
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