Can't adjust the idle with the big brass screws (BBS)

[DonW]

In a recent very long thread- "Not as smooth as it was", many of you helped try to sort out some ongoing issues with my '04 1150RTP. I'm going to try to attack some of the problems one at time. First up-

 

After a wonderful long ride yesterday, I tried to get the idle speed up (has been at or below 1000rpm lately). Using only the BBS's, I didn't seem to be able to change it much, and never could get it above 1000rpm. I think I've read I'm not suppose to mess with the idle stop screws on the TB's, but...

 

BTW, I pulled both BBS's, cleaned them (some sort of thin black coating on both), re-seated them, and started at 1 1/2 turns out.

 

Thanks,

 

Don

[Boffin]

Use some cat-safe cleaner spray and give the BBS ports a good clean out too.

Andy

[T__]

Don, that is usually a sign that the BBS channels in the TBI’s or BBS seats/screw tips are coked up & not flowing proper by-pass air..

 

Try removing both BBS screws & cleaning the screw tips spraying some 02/cat converter SAFE spray (carburetor) cleaner into the TBI ports..

 

Then reset to 1-1/2 turns out & start the idle TBI balance/idle speed adjustment over again..

If idle still to low remove the air intake boots & clean the coaking from the TBI throttle plate closing area..

 

If you REALLY have to you can work with the TBI base throttle plate idle stop screws but you need to know what you are doing & keep them in step with the TPS so ELIMINATE all other options before messing with those..

 

Twisty

 

[Selden]

+1 for what Twisty says. My brass screws were about a full turn apart, with the right one less than a half turn out. After I cleaned both thoroughly, I got a nicely balanced idle, at the speed I wanted

[boatzo]

Ditto Twisty and Seldon. My BBSs work fine after cleaning inside and out.

[DonW]

Will do. I have the extra set of TB's from my parted out '03 on the bench which make makes it easier to figure out what I'll do on the bike. I think I better get a spare set of the large O-rings before I pull the intake boots.

[T__]

Don, new “O” rings are never a bad idea.. At least that way you will have a spare set around.. If you place the removed ones in the hot sun for a while the fuel that is swelling the rings will evaporate & allow easier re-installation,, better yet --after the sun thing place them in a plastic bag & put in the freezer for a while they should then go right back in with no fuss or muss..

 

You might first try just cleaning the BBS screw BORES on the TBI’s on the bike as that usually does trick without having to remove the intake tubes or messing with the “O” rings..

 

 

Twisty

 

[DonW]

Yes, will clean the bores first, but want the O-rings as spares and "jsut in case" anyway.

 

After spraying the bores, is it OK to give a blast with compressed air??

 

Don

[T__]

Don, yes I usually give it a little blast of compressed air after the cleaner softens the coking a little.. Not too high of a pressure but a reasonable shot will help dislodge the black goo..

 

 

Twisty

 

[DonW]

OK, cleaned the BBS and port, but no difference. Abandoning this for now, as neither of my lower spark plugs are firing (may have been weak until complete failure earlier today). Starting a new thread re the bad coil/spark? Please refer to "Bad main coil on dual spark 1150RTP" for new thread.

[carolinarider]

Hey Don, I went through the "no spark" crisis a couple months ago. Turned out the wiring on the HES was shot. Replaced the sensor, adjusted valves, synched the TB's and running good as new...