Boxer Cup update...

[vintrace]

Thanks to the great service style manual I downloaded from this site I have now worked my way through my BC.. this includes-

All oil changes
Valve adjustment including the vertical carrier lash
Air cleaner
New style chain tensioner
Cat eliminator pipe
New spark plugs,
New R/H stick coil which made a huge difference
Throttle body synch
Fueling module from 'Beamer boneyard' also made a huge difference.

So now with all your help and the info on the site I have a transformed bike. It idles lovely, revs clean thro the revs and is returning about 50mpg

I do have one last glitch.. I have picked up a nasty vibration. Up to 4000rpm the bike is a dream..smooth with zero surging, pulls well in any gear.
Once I go past 4000 rpm I get a pretty high pitch vibration.. not quite as bad as the 4-cyl vibe but getting close... very obvious thro the foot pegs and knees. It gradually gets worse the more I rev it.. at 7000rpm its pretty bad.. bad enough to make you feel like changing up pretty quick...
In fact on my last ride I came back and one of my bar end weights had gone... vibrated off.. !! which by the way cost a silly $65 to replace..! And no screw included.!
Any ideas most appreciated...

[RIQUE]

Originally Posted by vintrace

Thanks to the great service style manual I downloaded from this site I have now worked my way through my BC.. this includes-

All oil changes
Valve adjustment including the vertical carrier lash
Air cleaner
New style chain tensioner
Cat eliminator pipe
New spark plugs,
New R/H stick coil which made a huge difference
Throttle body synch
Fueling module from 'Beamer boneyard' also made a huge difference.

So now with all your help and the info on the site I have a transformed bike. It idles lovely, revs clean thro the revs and is returning about 50mpg

I do have one last glitch.. I have picked up a nasty vibration. Up to 4000rpm the bike is a dream..smooth with zero surging, pulls well in any gear.
Once I go past 4000 rpm I get a pretty high pitch vibration.. not quite as bad as the 4-cyl vibe but getting close... very obvious thro the foot pegs and knees. It gradually gets worse the more I rev it.. at 7000rpm its pretty bad.. bad enough to make you feel like changing up pretty quick...
In fact on my last ride I came back and one of my bar end weights had gone... vibrated off.. !! which by the way cost a silly $65 to replace..! And no screw included.!
Any ideas most appreciated...

From your post you seem to have done a pretty thorugh job. Have you switched to synthetic oil engine and gearbox? Make sure you pass a couple of bottles of fuel injector cleaner through your tank. At high reves fuel injector discharge difference and jet pattern can make a...difference.

[vintrace]

Thanks I will certainly give that a try.

Before I did the sync I removed the brass needle jets and polished them... they were not bad just a bit black. I then set them at 1.5 turns out, loosened off the cross over cable from the R/H cylinder and did the sync at 1100 rpm on a warm engine.. I have a really good even idle...
Next I ran the motor up to 4000 rpm and watched the sync tubes... some adjustment on the cable was needed but a bit of trial and error they came very close... my R/H and l/H brass jets are within a 1/4 of a turn of each other. So not sure if I missed anything...
Cheers

[kroberts]

Regarding your vibration; How many miles on the bike?

My bike had an unnerving vibration but I had been assured by two local beemer authorities that is was "normal". I just finished replacing my entire clutch package including a new transmission input shaft. The job completely transformed my bike. I cant stress what a difference it made. My bike had 43k miles on it, the shaft and clutch splines were toast.

If your bike has never been cracked open it might be time.

[Nitro]

High speed throttle bodies sync and also do a TPS reset. Are you still running lean?

[vintrace]

Hi Guys, well thanks for the response... well I think Thanks the thought of pulling the motor to do the clutch is a bit beyond me..!

Hi Nitro, the fuel module I fitted has done away with all the lean fueling and the bike is so much better... no surge, nice idle and and plenty of throttle response. I set the TPS at .39
The new stick coil on the R/H cylinder also made a huge difference in performance..its pretty much all the performance I need now its running good.
Yesterday I did a 150 mile run on the bike.. under 3800 rpm I could ride it all day.. smooth and quiet. At 4000 rpm the fun starts to go away and at 5000 rpm on the freeway its miserable... if I pull in the clutch at 80 mph and coast the vibe disappears instantly.. so no chassis or wheel balance problems.
When I first got the bike it did have all the side to side vibes from running rough and shook the mirrors at certain revs.. but this is a much higher pitch vibe that gets much worse with revs.. if I pull it to 7000 rpm the vibe is awful.
It almost feels like I have done something to introduce the vibe.. could the exhaust link pipe mess things up...? I dont see how myself..
At a loss at the moment

[kroberts]

How many miles on the bike?