Yamaha YB 1 1999 tidy-up
Moderator: Bootsy
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911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
You could be right!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
You could be right!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
Of all the 2 wheelers Ivedone thisone is my second favourite, might even use it!
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
Cortina
- DDK rules my life!
- Posts: 1233
- Joined: Tue Jan 17, 2006 6:32 pm
- Location: N.Ireland
Re: Yamaha YB 1 1999 tidy-up
.. to be sure .... to be sure ...........
Royal Enfield .. still in India
GL 1800 Tour DCT, for pleasure / Fantic 240 Professional - play
Rally 911 (1966) build parked for a while
Rally 928 (work started again - inc serious weight loss programe !)
.... and now another VW Up GTI owner.
GL 1800 Tour DCT, for pleasure / Fantic 240 Professional - play
Rally 911 (1966) build parked for a while
Rally 928 (work started again - inc serious weight loss programe !)
.... and now another VW Up GTI owner.
-
911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
neilbardsley
- Nurse, I think I need some assistance
- Posts: 8619
- Joined: Mon Apr 16, 2012 4:31 pm
Re: Yamaha YB 1 1999 tidy-up
Thumbs 
Sent from my 22011119UY using Tapatalk

Sent from my 22011119UY using Tapatalk
“A REMINDER. I would be grateful if those members who have borrowed bits from me in emergencies (e.g starter motor, oil cooler, etc) would return them and/or contact me”. – Chris Turner RIP
-
911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
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?
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?
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
Cortina
- DDK rules my life!
- Posts: 1233
- Joined: Tue Jan 17, 2006 6:32 pm
- Location: N.Ireland
Re: Yamaha YB 1 1999 tidy-up
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.
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.
Royal Enfield .. still in India
GL 1800 Tour DCT, for pleasure / Fantic 240 Professional - play
Rally 911 (1966) build parked for a while
Rally 928 (work started again - inc serious weight loss programe !)
.... and now another VW Up GTI owner.
GL 1800 Tour DCT, for pleasure / Fantic 240 Professional - play
Rally 911 (1966) build parked for a while
Rally 928 (work started again - inc serious weight loss programe !)
.... and now another VW Up GTI owner.
-
911hillclimber
- Nurse, I think I need some assistance
- Posts: 20620
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Yamaha YB 1 1999 tidy-up
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.
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.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9








