Where are those throttle cables?

[zeke]

As bit of a short back story: performed the left side cam tensioner, no issues, easy to do, highly recommend it, thanks for posting the walk through. I cleaned both sides after I installed the tensioner. test ride. seems fine, great response from the bike.

Now the strangeness: notice the idle is now high. close to 1500 rpm. check that the fast idle was off, it is. check the throttle cables near the BBAS, you know the ones that can get pulled outta place and create havoc. Those are firmly in place. Grab the twinmax, low idle is close to balanced, a smidgen of an adjustment brings it to zero, but I cannot get the idle speed to come down. I made several adjustments and various combination to no avail. Then I check the high: open the throttle to 3500 rpm and the twinmas pulls heavy to the left. This is a major shift from my last few checks where the high side had been spot on. My thought is that somewhere along the way I dislodged the inside portion of the left side throttle cable during the tensioner upgrade. Does this make sense? Where are those cables located inside the bike? Looks like they go under the air box, but I'd like to have a general idea of where to look than going on an exploration. Thanks for the help. -Zeke

[Devo3136]

Mine did the same thing I turned the bbs to about 3/4 turn out from seat thats where the idle was around 1000 rpm then synch your throttle bodies again. Runs great now. The 1.5 turns out is just a starting point all bikes are different mine was happy at 3/4 turns from seated.

[boxermania]

If TwinMax pulls heavy to the left, (assumingh the TB's were balanced before) that means there is an air leak on the right TB. Check the hoses at both ends.

[CycleRob]

Then I check the high: open the throttle to 3500 rpm and the twinmas pulls heavy to the left. This is a major shift from my last few checks where the high side had been spot on. My thought is that somewhere along the way I dislodged the inside portion of the left side throttle cable during the tensioner upgrade. Does this make sense?

Yes!

1--If you removed the TB to gain access to the tensioner, that was an unnecessary mistake and likely caused the cable pull-out -or- bending (slightly) of the TB cable bracket causing the imbalance shown by your TwinMax. Readjusting the synch error at this point would be ill advised, as it is obvious the work performed caused the error, giving you the 1,500 RPM "idle". If it was bracket bending that caused it, I would not re-bend it back as the 1,500 idle indicates it did not bend that much. Re-bending could risk weakening it. Just re-synch it.

2--Check the throttle cable routing on both sides. There should be no direction distorting contact with either cable. Open the throttle fully to the stop. Apply additional opening throttle twist against the limiting stop with the full power a of 6 year old girl That should seat any minor cable-end pull-out. You may even feel it seat itself to a new, firmer stop. Recheck the on-throttle synch. BTW if your guesstimate of a 6 year old is more like a 9 year old tomboy, (disclaimer warning) the plastic throttle grip cable attachment point may be damaged. Use your good judgment, realizing that in your distracted enthusiasm while riding the bike with friends you may actually hit that full throttle stop more like a teenage boy overloaded on systemic testosterone . . . . with no damage at all.

That's all I got, but that should resolve it.

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[zeke]

I'll give the cables a check, using that method. Visually from what I see they look normal, but I can only see so far before they get lost inside the bike. I have to say my strength estimation is bad. Just for planning in the event I do damage the plastic throttle grip attachment, is it easily replaced? Can it be inspected visually? I have been meaning to get the tank off and replace the battery anyway, maybe this is a good excuse/reason. Thanks for the help.

[keithbw]

I had a similar problem, I had pinched the TB o-ring, where the intakes fit over the throttle bodies. Replaced said o-ring and, while I was at it, the little thicker ones on the injectors. Problem solved. Idle air screws even, and no swings in the vacuum drawn at different RPMs.

Even if you did not remove the intakes, maybe you put enough lateral force on them to damage the o-ring, or it is just old.

They are surprisingly insubstantial, considering the force needed to pull the intake tubes back out of the airbox when re-installing the throttle bodies.

They seem so easy to damage, that I hope Beemerboneyard will add these to their maintenance inventory.

Brian

[CycleRob]

Those thin O-Rings between the TB and airbox inlet tubes are problematic. The problem is when you force on the inlet tube it squashes the O-Ring on one portion, causing the still free portion to get longer - - forming a protruding loop. Then it doesn't want to be stuffed back in place. If that loop is on the back side where it may go unnoticed, you will pinch it and it'll leak air.

My solution was to grease smear the entire O-Ring surface, then push on the black plastic inlet tube aligned so it contacts the O-Ring evenly all the way around while it it's open end is midway over the O-Ring's channel. Turning the angled end tube gets it in that perfect alignment. There is also an alignment bump on the tube. Look for it before you even remove it. The chances are good it will not be perfectly aligned with the TB seam. Back to the install, with a flat screwdriver blade start tucking the O-Ring under the tube all the way around as you slowly push the tube on further. At some point the O-Ring is in it's channel and completely covered by the inlet tube. Go very slowly and methodically with the screwdriver in one hand and the inlet tube in the other and it just goes together. A better solution might have been to use a smaller ID, fatter cross section O-Ring that needed to be stretched on just a little. BTW, if that O-Ring leaks air, it will not affect the idle, it'll just let in small amounts of unfiltered roadside air.

You can replace the fuel injector O-Rings too, but removing, cleaning and greasing them extends their lifespan while improving their sealing function right now today. My 2002 model's injector O-Rings seemed too dry to seal the high manifold vacuum at an idle or decel when they were pulled out for inspection of the spray nozzles for deposits. I don't know if it was the placebo effect or reality, but I swear it idled really smooth afterward.

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