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Re: Yamaha YB 1 1999 tidy-up
Posted: Fri Oct 13, 2023 9:02 pm
by 911hillclimber
You could be right!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
Re: Yamaha YB 1 1999 tidy-up
Posted: Fri Oct 13, 2023 9:02 pm
by 911hillclimber
You could be right!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
Re: Yamaha YB 1 1999 tidy-up
Posted: Fri Oct 13, 2023 9:10 pm
by Cortina
.. to be sure .... to be sure ...........
Re: Yamaha YB 1 1999 tidy-up
Posted: Mon Oct 16, 2023 1:01 pm
by 911hillclimber
Re: Yamaha YB 1 1999 tidy-up
Posted: Mon Oct 16, 2023 8:29 pm
by neilbardsley
Thumbs
Sent from my 22011119UY using Tapatalk
Re: Yamaha YB 1 1999 tidy-up
Posted: Tue Oct 24, 2023 12:45 pm
by 911hillclimber
Just doing a test here:
Re: Yamaha YB 1 1999 tidy-up
Posted: Fri Oct 31, 2025 1:16 pm
by 911hillclimber
Time to revive an old thread!
Still have this little bike, for sale if anyone interested.
I am always trying to improve things on all the 'fleet' and the Yamaha is included.
I feel it is being over charged with oil (it is a 2 stroke) at low rpm such that eventually it fouls the plug.
A quick wash in car cleaner and all is well, but irritating.
I think the pump for the upper lubricant is passing too much at tick over, and I need to tweak he stroke.
Fine job down to 2 or 3 though shimming.
anyone bike type on here done this?
Re: Yamaha YB 1 1999 tidy-up
Posted: Sun Nov 02, 2025 4:11 pm
by Cortina
Over oiling ?? Hmm , don't know how you would know , as I'm guessing it has not been ridden properly. By properly - when did it last/ ever go for a 15 to 30 mile spin , including a variety of riding (slow speed / fast speed , little throttle , full throttle , etc etc) and get fully up to real working temperature. ??. Upper lubricant ? - surely it does big end / main bearings too .
Never adjusted one of these pumps , so can't help you ... but "be sure" you actually have a problem first . Apologies if I am talking rubbish.
Re: Yamaha YB 1 1999 tidy-up
Posted: Sun Nov 02, 2025 10:36 pm
by 911hillclimber
Good points made.
I have not ridden the bike, not sure i ever will now as I do not like the road conditions around me here, too few drivers understand bike riders. I've been knocked off 2 wheels before!
I start the bike every 2 to 3 weeks to keep the battery alive. (12V, kick start).
The engine is run at fast tick over, blipping the throttle etc for about 5 mins until i can't touch the silencer down pipe.
The Yamaha system is giving a metered oil dose dependent of throttle position, so full open throttle get more oil added.
I've eventually found the clearance figures for the metering cam at tick over etc, so this will be the task this week.
A simple brass washer/shim does all the metering setting the tick over position and then the cam does the increase. There is a 6 thou starting gap at a set tick over position.
The bike is 1999, quite modern but info is hard to find.
