Honda CB72 Racer

LOUD MOUSE · Post by **LOUD MOUSE** » Fri Sep 07, 2007 9:08 am

What are those black rods going from the rear of the the engine to the front of the frame and along both sides of the engine?. .....lm

s3nss wrote:Hello guys ,

last year my father bought a honda CB72E racer with some special parts ; tomaselli clip ons - four leading front brake - akront rims - high compression pistons - close ratio gearbox etc etc . this week it was alive for the first time , was not running so well but after modifying the jets it serious kicked some ass :)
Did a couple of test runs , and discovered a leak at the outgoing gearbox shaft , where the front gearwheel is fitted,i think its the seal inside the bronze bush !! Not shure ,, but ok now my question ; does anyone have a drawing how its all fitted ? i cant see it from the outside . So if anyone can help us , in advance thank you !
attached a picture from the gearbox shaft and the machine complete ...
excuse me for my drossy english but normally i write/speak dutch !!

s3nss · Post by **s3nss** » Fri Sep 07, 2007 9:59 am

Those rods serve to consolidate the frame , there's now less force and vibrations against original.
it's a nice construction actually !

LOUD MOUSE wrote:What are those black rods going from the rear of the the engine to the front of the frame and along both sides of the engine?. .....lm

s3nss wrote:Hello guys ,

last year my father bought a honda CB72E racer with some special parts ; tomaselli clip ons - four leading front brake - akront rims - high compression pistons - close ratio gearbox etc etc . this week it was alive for the first time , was not running so well but after modifying the jets it serious kicked some ass :)
Did a couple of test runs , and discovered a leak at the outgoing gearbox shaft , where the front gearwheel is fitted,i think its the seal inside the bronze bush !! Not shure ,, but ok now my question ; does anyone have a drawing how its all fitted ? i cant see it from the outside . So if anyone can help us , in advance thank you !
attached a picture from the gearbox shaft and the machine complete ...
excuse me for my drossy english but normally i write/speak dutch !!

s3nss · Post by **s3nss** » Fri Sep 07, 2007 10:11 am

ok thanks , I will attempt to do it and hopefully it works...
I let you know something if i want to order the seals !!
Regards John

LOUD MOUSE wrote:I agree with Randy that this seams to be reversed as for parts installation. As for me I'd get a tool with a hook and using the hole I'd pull the metal part out. I suspect you will find a seal behind it. Don't get to worried about damaging the metal part as when you reinstall it (followed by the seal) all it does is place a depth limit for the seal. HONDA part number for the seal is 91205-259-000 and if ya can't locate one I have them here in TEXAS. Come to think of it ya may want to look at the clutch end of this shaft and check for an "O" ring inside the shaft where the Clutch Lifter Joint/Piece installs. HONDA part number 91305-259-000. ...........lm

rrekr wrote:John,
The bushing in the stock maindrive gear is quite thin and to my knowledge was never sold as a service replacement part. If these were simply installed out of sequence, (hard to imagine), there is a chance you could go in from the clutch side on the mainshaft. The hole through the stock mainshaft will start as 13mmØ and then neck down to 12mmØ. You could possibly use a rod less than 12mm to knock out the seal and bearing. I would reinstall in the factory order to insure lube to the bushing. Be particularly carefull when you reinstall that very thin bushing, the factory original had a heavy press. As far as the movie, YES! Also,if you EVER take the engine apart, I would love to see some pictures.
Thanks,Randy
PS When I said thin, I was referring to thickness.

305racer · Post by **305racer** » Sun Sep 16, 2007 11:56 am

s3nss nice bike you and your dad have and it sounds like it runs pretty strong too. What shocks are on it and do you know anything about the gear box?

s3nss · Post by **s3nss** » Wed Oct 17, 2007 8:55 am

finally , last week the seal is replaced ! as a matter of fact it was an easy job to replace the seal .
No more leaking now :-)
Still got a question and hoping someone can answer me .. How much oil may we give to the engine ?

@ 305racer : thanks , the shocks are koni's which are restored ! much rather than original.
About the gearbox i dont know anything i'm sorry , the only thing we know is that the first gear is a very long one and the next three very short , kind off close ratio i suppose

rrekr · Post by **rrekr** » Wed Oct 17, 2007 9:02 pm

Hello s3nss,
Standard CB72 is 1.5 Litre. Does this bike not have a dipstick?
PS: Leaving for the race in Birmingham now, if you reply, I'm not ignoring you, I'm on vacation:)
Good luck,Randy

s3nss · Post by **s3nss** » Wed Oct 17, 2007 9:26 pm

rrekr wrote:Hello s3nss,
Standard CB72 is 1.5 Litre. Does this bike not have a dipstick?
PS: Leaving for the race in Birmingham now, if you reply, I'm not ignoring you, I'm on vacation:)
Good luck,Randy

Thanks Randy !!
Bike has no dipstick.needed to fill the oil trough the crankcase ventilation so the first time it was a little bit guessing . anyway this time it will be correct i hope :)
Good luck with the race
Greetings John

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