2002 R1150RT - Throttle Body Cleaning

[dagear]

This is related to a post I started on R1150RT Surging issue. Last night I found a faulty lower O-ring on one of my injectors. They are currently in the mail to MrInjector.us.

While I have the bike this far apart, I am contemplating cleaning the Throttle bodies, but I can't seem to find any discussion/threads on this topic. If they exist then I must not be searching correctly.

Does anyone have a link to proper procedure on Throttle Body Cleaning?

BTW, I think I am going to go ahead and replace the brass screws & Throttle Body O-rings

 

[pauls1150]

Dunno if there's a specific link or instruction set...

Wipe the bores with a clean rag wetted with gas or alcohol.

Squirt some carb cleaner down the little holes that the brass air screws came out of - WEAR EYE PROTECTION, the spray will bounce back out at you.

PRIOR TO squirting cleaner down the hole, wet a Q-Tip with gas or carb cleaner and wipe out the bottoms of those holes - you can accumulate a bit of chunky glop down there. Some is from the gas, some is whatever may have gotten by the air filter, some is from the breather (bottom of the airbox).

Recommendation: Prior to squirting down the holes, turn the engine over so that the intake valves on that side are open, and remove the lower/outer (perimeter of the combustion chamber) spark plug - this will give the cleaner a place to exit easily. Left in there, it may not readily evaporate, and it may dilute the oil on the cylinder wall - not good at the next start-up. And since it wasn't atomized with the fuel, it may make the next start-up more difficult. Some cleaners may not be compatible with the brass screws' O-rings, so make sure everything is dry before reassembling.

Also verify that the main shaft is not loose in the bore; this can be an air leak. Rebuild kits are available for this.

(re that injector O-ring - Ain't it a great feeling to actually FIND a culprit!)

 

[aapasquale]

I changed my throttle cable on my 1994 R1100RS a few days ago. In order to do that, I had to (according to Haynes) remove the throttle bodies from the attachment to the cylinders. To make a long story short...it turned out well. When I had the throttle bodies out I saw that the interior looked pretty nasty (deposits). I sprayed carb cleaner through the idle adjuster screwholes and it appears they are not clogged. However, turning the screws out...even all the way...does not alter the idle speed. What does that mean? idle sits at a comfortable 1,000 rpm, and sync is good, but I would like to see these screws function properly. What can cause this?

So I don't hijack this interesting thread entirely, is it better to remove the throttle bodies entirely from the bike to clean them thoroughly? I'm also having the injectors cleaned and balanced this winter while it's all apart. The throttle position sensor will also have to be removed (I assume) to clean the body....Yes/No?

I apologize in advance for the intrusion into this thread, but it is related to some questions I had in mind concerning my work on my bike.

Thanks
Tony

 

[pauls1150]

If the big brass screw does nothing, then you may still have crud down there in the tiny little passageway, or sticking to the screw itself (hopefully you pulled them out completely?), AND/OR you have an air leak somewhere (the intake mounting flange, the shaft bushing, or the O-ring on the screw). It is possible that your throttle stop screws are set to hide this problem; also check that you really have a little slack in the cables before the twistgrip actually moves the throttle plates.

re the screws' adjustment - That's a pretty small passageway, and the screws are tapered; anything "looser" (more out, counterclockwise) than 3 turns is probably meaningless, since the passageway would now be fully open.

You can do a pretty good job of cleaning the throttle bodies with them still on the bike - look into the throats (with the air tubes off); they're pretty simple in there. Make sure to clean the "ring" of buildup where the body's bore meets the throttle butterfly plate.

 

[aapasquale]

Thank you Pauls1150,
I will check the freeplay on the main throttle cable again. I did pull the brass screws out completely and cleaned them. I will check for air leaks around throttle bodies and manifolds.

 

[dagear]

Thanks Paul's 1150

My throttle bodies were extremely dirty even after trying to spray with them installed. They are easy to remove the first two Q-tips down the brass screw holes came out pure black

One of the plates had so much crude that it would not always return to throttle stop

I have been fighting the surging issue on this bike for quite some time I'm having injectors cleaned now with throttlebody's cleaned anxious to see how it runs

BTW I am replacing brass screws and throttle body o rings

 

[dagear]

Received new parts today

Cam tensioner
Cleaned injectors
New orings on TBS
new brass screws
Cleaned throttle bodies

Used home made manometer to balance tbs

Initial ride looks good may just have driveshaft backlash

 

[PGlaves]

Some back lash is normal. Look for leaks. Listen for ugly sounds. Otherwise, some back lash is normal. Ride her!!!