05-29-2021, 10:50 AM
(05-28-2021, 10:31 PM)j3gq_imp Wrote: lazz, really sorry to hear about this problem. As others said, there could be many reasons. But you would certainly go from doing ALL the easy/cheap tests, before tackling more difficult/expensive solutions. May be taken the engine apart is the only solution - but it is certainly the last ever considered. Now this said - unless you park her in the dealers yard and he is willing to fix it for you (which I doubt) ... if it was my bike, and after all you did already, I would do the following:
- first ask the dealer to use his connections, and organize a ride on another CB for me, just to be sure (that you can feel the difference),
- you said it's rpm/s not speed, so go to that rpm range in third gear (not higher !), pull the clutch AND keep the throttle open so the rpm doesn't fall off, what happens ? same vibrations, or less, repeat until you are sure;
- it can be rpm/s and NOT be the engine, we need to know for sure, which is very difficult to say at high speed and rpm/s with your hands tortured;
- strap several accelero-meters (best the recording type) to places like fork, engine, tail etc. and get the frequency spectrum read-outs for each to compare. where is the problem located, what is just resonating, resonances, all objectively (your wrists may just be more sensitive than other body parts; have some one who knows these devices check the read-outs for you.
If you don't know how to do this, there may be guys at the race track or (if you are near water) the power boat guys who may be willing to help with this. If not, local mechanics department at the university.
Thanks for that
Will try pulling the clutch even though I'm 99 per cent certain its the motor, it can't hurt to have more info...
I got a very experienced motorcycle mechanic friend (40 years experience) to ride it today and another friend who has ridden only Japanese I4s for about 15 years, they were both amazed at how rough it was.
In the affected rev range the resonance is very very strong. A lot more than one might get from a loose or overtensioned exhaust.
It can be felt everywhere, the seat, pegs and the tank as well as the handlebars.
It is definitely rpm related and not vehicle speed related.
The accelero-meters road sounds really interesting. I'm less enthusiastic about that than I might otherwise be as I have a LOT of work on this year, so I just can't let this become too much of a project... I bought the Honda hoping to just turn the key and ride. (I have rebuilt a fair few engines and gearboxes, made custom wiring looms etc in my time so I'm no stranger to projects!!)
A question for everyone that has me stumped, how does the balance shaft adjuster actually work? It was easy to set, but I'm having a bit of trouble visualising what's going on inside the carnkcase when the adjustments are made. And the parts book is not too enlightening...
Thanks everyone