Modified from original post
$15-fast-easy-OilHead Throttle Body Repair with ball bearing assembly
I had a 2002 R1150RT with worn throttle shafts/bushings. Just added a bearing. Runs great.
I did NOT replace the shafts, or pull the cable pulley from the shaft.
No meter used. But it cost $5/side, works perfectly so far, and the wifes riding it now.
I marked the throttle position sensor location.
I removed and disassembled the throttle bodies, ( clips on end opposite the cable pulley's) pulled the rubber seal from the recess in the cable side of the housing, scraped the recess clean, froze the shaft ( freezer); tapped the bearing assembly all-the-way onto the shaft ( carefully, with a tube I made) , reassembled shaft to housing ( don't break those plastic pieces for the spring).
I loosened the throttle stop screws, painstakingly centered the throttle plates ( butterflies) in the bore, while checking to a bright light, to eliminate air leaks ( high idle) and Locktite'd the throttle plate ( butterfly) screws.
I used a small piece of paper as a feeler gauge between the throttle stop screw and the throttle, set to drag thru gently, then tightened a further 3/4 turn; to set the throttle plate angles the same. Locknut'd.
I set the pilot air screws to 1 turn, after cleaning them and the air holes ( carb cleaner and Q-tips).
Install throttle bodies, loosen cables. Less than 1 hr. per side, after the bike covers were off. Replaced TPS, lining up paint marks I had made.
Using a homemade manometer, attached to bottom of throttle bodies, and the tachometer in the dash, I used the brass pilot air screws ( BBS) to set and sync the idle speed to 1100rpm ( engine warm).
Then set 1mm cable play and synced the cables at 2500-3000 rpm.
cata motronic learn
turn on ignition, remove #5 fuse for 30sec, turn off ignition
replace fuse, turn on ignition, twist throttle to stop and back 3 times, turn off ignition.
Install the covers, go riding. ( today)
Manometer was made with 1/4" x 20' long clear plastic tube, taped to a stick, partially filled with transmission oil ( can suck it in - 6' is enough). Wife said it looked like bike was on life support ( intravenous).
2002 R1150RT throttle shafts were worn, at the cable side bushings; except for 3mm, where the shaft seal is in a recess in the exterior of the throttle body. An 8mm x 13mm x 3.5mm ball bearing assembly will tap onto the shaft, then fit in the recess for the seal ( remove the seal).
No other changes were required. No play at all. Throttles turning smooth and easy.
Bike runs the best since we got it. 89,000 miles on odometer.
SMR138XZZ 8mm x 13mm X 3.5mm ABEC-3 Stainless Steel Bearing available from www.rcbearings.com
or E-bay.com ( US) same outfit, I think e-bays cheaper. shipping included.
Each bearing and the manometer were about $5 each.
Tool: To tap the bearing onto the shaft. I made a 4" long driver tube with one flat end larger than 13mm ( to push against the bearing) with a 21/64" hole (to fit over the throttle shaft). I lubed the throttle shaft. Could alternatively drill a hole in wood, place a washer with a 21/64" hole over it, then the bearing, then gently drive the shaft through the bearing ( don't drive the shaft out of the cable pulley).
I believe that if the shafts are loose in the bushing ( worn), the factory throttle stop screw ( idle speed screw) setting doesn't mean much. Also, on many bikes, who knows if they've been changed.
Backing off these screws allows the throttle plates ( butterflies) to center and seal, before tightening. There's lots of room in the throttle plate screw holes for mis-adjustment. I also have some throttle plates that are slightly different shapes, don't know if that's wear or manufacturing.
Some inet sites said 0=0 doesn't work on this bike, and that this newer motronic adjusts itself ( when reset as above).
This is the ONLY bearing that size, I could find. They listed 180 left.
Bearing is small stainless steel, w/metal shields both sides, inner race sits against bushing.
I believe there's close to 0 airflow through the bearing, not enough to affect idle.
There does appear to be 8mm x 13mm x 4mm bearings available but possibly the seal recess would have to be deepened. The only ones I found with seals were 4mm wide ceramic. Scared to use ceramic, because tapping them might break them??.
I did try other settings first, this is what worked for me.
I don't anticipate any more wear issues, but I never talked to Murphy.
Hopefully it lasts awhile or forever. One way to find out.
I've had airhead carb shaft/bushing wear similar to these throttle bodies.
I think they could have used a better design where the bushings wear instead of the shafts, and were easily replaceable.
Disclaimer: If you do this, it's your responsibility. No guarantees/warranties.
It wasn't my fault
I wasn't even here/there that day
I cnt Evn spl N-gnere
I'm dead anyway! Epitath: He said he would take the wifes bike apart to take pictures.
Warranties come with new bikes.
I don't know if it could ever turn out even worse than the stock bushing setup.
But it cost $5/side, was easy to do, works perfectly so far, and the wifes riding it now.