hello sam ,
well , i had the bike as a stock 400/4 ,in 78, and was studying turbo charging ,so used it as my 1st test bed .
i bought a new ihi rhb5/1 turbo,and built the manifold from the original exhaust system ,then made a inlet , from some aluminium box section . i originally connected this to the head with some thick rubber gaskets ..needless to say these blew out ,and its now fixed solidly with a smear of silicone .
for carburation i used a stromberg carb at first ,but then moved to a cv bike carb .timing was fixed at 24 degrees .
the head was ported ,and a 450 cc yoshimura big bore kit is fitted . i used a few extra base gaskets to lower compression ration to 8.5 to 1 .
one major design flaw ,was to use a bolt on the oil pump with a hole drilled down it and a lip in the top as the take off for the turbo ,which would have beeen ok if id used some proper oil pipe ,but i used that braided see through stuff ,and it shot off at about 60 mph uphill round a corner ,covering the rear tyre in oil ,so i ended up going up hill at 60 on full lock like a speedway bike ....but didnt fall off ,amazing .then pushed it 2 miles home .
some proper braided was aquired .
i had a few experiences of sending the piston rings down the exhaust as i learnt about detonation ,and was using 13 psi max ,and 13000 rpm .
after i got the big bore kit its been fine ,and also it was benifitting from a better setup as i learnt my way during the early 80's .
i did 10 000 miles on it despatch riding from high wycombe long distance .and ,apart from the occassional tendency for the carb to come off the turbo inlet , it was fine ,even got about 50 mpg .
on the dyno it had in the end ,85 bhp at 8500 rpm ,tihs was when the clutch gave up . pk power would have been around 10 000 rpm .;but the clutch had no hope .
regards robert .
