R90S Carbs Sorted!

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Troy Nicks
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Posts: 41
Joined: Wed Sep 22, 2004 5:46 am

R90S Carbs Sorted!

Post by Troy Nicks » Sun Nov 07, 2004 8:54 pm

Since I whined a fair amount at the Nov. 7 ride breakfast about motor problems with my R90S, I thought I'd report that all's well.

Turned out to be a simple thing - the carb main jet needles were on the top notch which was starving the motor at 4K and above. I think I may have put them in that position last time I cleaned the carbs. Anyway, I moved the needles to the middle notch and that took care of the problem. Bike's running strong now.
Troy Nicks
Nelson Co., Virginia, on the Tye River
04 K12GT

AntonLargiader
Posts: 256
Joined: Mon Jul 12, 2004 7:43 am

Post by AntonLargiader » Mon Nov 08, 2004 9:52 pm

Definitely read the plugs, though. Best way would be to ride for a while at the speed that was giving you problems before, and after several minutes of that just kill the motor (tough with the Boyer, I know!) and coast to the side with the clutch in. Pull the plugs and see... might tell you to go one more notch.

You might be able to kill the engine with the choke.
R1100RS, R100R, K75RT, R100PD, R100GS, XR400R, R75/5x2, Jetta TDI

Troy Nicks
Site Admin
Posts: 41
Joined: Wed Sep 22, 2004 5:46 am

Post by Troy Nicks » Fri Nov 19, 2004 6:53 am

Ya know, Anton, something was still nagging at me about the needle notch so I checked Clymer's and sure enough, it's supposed to be in the bottom, not middle notch. Actually, it says "third" notch. I think I'd previousy misread that to mean third from bottom notch rather than third from top. So, I reset them again to the bottom notch but haven't had the bike out yet. Wouldn't want to run that puppy too lean, would we?

The Boyer instructions mention that with "some" BMW's, you won't be able to kill the engine with ignition key or kill switch. Something to the effect that old systems "leak" enough power to run the unit. Anyway, that's apparently going on with mine. The instructions include some minor reconfiguration to the unit's wiring to eliminate this little irritation. I got some OEM hose clamps so I'm ready to yank that tank off and get the Boyer straightened out.

Sure do appreciate your help in getting this old beast back on the road. Ya hoo!
Troy Nicks
Nelson Co., Virginia, on the Tye River
04 K12GT

AntonLargiader
Posts: 256
Joined: Mon Jul 12, 2004 7:43 am

Post by AntonLargiader » Fri Nov 19, 2004 9:02 am

I was thinking about the Boyer yesterday. The /5 that I just got isn't sorted out yet but it's close. I'm gonna inspect the timing advance and if that area needs new parts I might be tempted to try the Boyer on it, even if I pull it off later on and swap parts with the race bike.
R1100RS, R100R, K75RT, R100PD, R100GS, XR400R, R75/5x2, Jetta TDI

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