rebuilding throttle bodies

[docc]

The Sport's been running awfully lean: popping on the overrun, stumbling at idle and such.

 

When I spray solvent into the spring on the bottom of the right throttle body, the idle goes up a couple hundred rpm. I presume the seal on the shaft is done.

 

Are these rebuildable with an O-ring or such?

 

Can I take it apart on the bike?

[gstallons]

Does his happen to the other side?

There is a good chance you can do this to ALL V11 bikes.

[docc]

It's not so pronounced on the left.

 

I've never had a throttle body apart. Surely, it couldn't be as bad as a carburator?

[raz]

I never did that test but I am sure I have the same problem. My springs underneath collect dirt very fast, and they drip. Very little, but it is there. I haven't got around to fixing it but I will follow your lead, it should be easy to dismantle it and hopefully find an o-ring there that is not too hard to find a replacement for.

[Paul Minnaert]

And you are shure that it ain't the intake rubbers? because they can have little leaks.

[docc]

I have retightened the intakes (maybe overtightened?), wrapped them with electrical tape and done the spray test on them.

 

I've thought to just replace them as a matter of course.

 

The positive spray test on the bottom of the TB shaft seems definitive. Does anyone else's raise rpm when the lower shaft is sprayed?

[andy york]

I haven't had time to dive into it yet...The unfortunate thing is that I don't think

there are any o-rings to replace

This was a problem on the Weber carbs on 911's ....the throttle shaft rides

on the aluminum body of the carbs. There was a place in LA that had a fix for the

Webers.

i actually saw a few drips of fuel run down the bottom of the throttle body.

If I rode in stop and go traffic this would be terribly frustrating. I don't so

its not. It is a little annoying.

Yes ...I have already tried the computer adjust and no luck.

Mine is 3K and below and I rarely ride at that rpm (when I'm being paced )

I have 55k on mine, yours is close to that, and I know of another at almost 30k

that might just be starting this.

andy

[docc]

So this may be a case of the shaft 'ovaling' out the housing?

 

All is well with the throttle open (which is where I like it after all! ), but slow speed turns and idling in traffic are annoying, even alarming if the thing pops in a turn pulling away from a stop.

 

I'm going to try to get to Corse Motorsports in Nashville the next couple of days and tickle the ECU with the Axone.

 

(57,500 miles on the Sport now!)

[andy york]

Did she ram your cargo into the back of the gas tank ?

I'm looking for a used set of throttle bodies to see what can be done .

hopefully high mileage

I at the shop now call me

andy

[Dan M]

It's not so pronounced on the left.

 

I've never had a throttle body apart. Surely, it couldn't be as bad as a carburator?

 

I've never had one of these apart either but you are right about easier than a carburetor. There is not much there. I doubt there is an o-ring or other rubber seal on the throttle shaft. Most rely on the fit of the throttle shaft against the brass bushing. The only replaceable seal is probably an o-ring on the air screw. (I'd certainly be interested to know if anyone has dismantled one of these and there actually is a replaceable seal) Try to wobble the throttle shaft from side to side. There should be a very small amount of play. If it is really sloppy the bushings are worn and that is the source of your vacuum leak. If it is snug, I'd look elsewhere.

[Skeeve]

This was a problem on the Weber carbs on 911's ....the throttle shaft rides

on the aluminum body of the carbs. There was a place in LA that had a fix for the

Webers.

 

Did they call this fix "...a heavy dab of grease?"

 

Just curious...

[docc]

I've never had one of these apart either but you are right about easier than a carburetor. There is not much there. I doubt there is an o-ring or other rubber seal on the throttle shaft. Most rely on the fit of the throttle shaft against the brass bushing. The only replaceable seal is probably an o-ring on the air screw. (I'd certainly be interested to know if anyone has dismantled one of these and there actually is a replaceable seal) Try to wobble the throttle shaft from side to side. There should be a very small amount of play. If it is really sloppy the bushings are worn and that is the source of your vacuum leak. If it is snug, I'd look elsewhere.

There is some play. Especially up and down on the right. Yours?

[stormsedge]

My right side has a drip and gathers dirt as well. I also have a stumble and pop right around 3Krpm that I have been unable to cure. I hadn't thought that this could be the problem, but am now suspicious of it. Pls post what you do to fix. k

[Dan M]

There is some play. Especially up and down on the right. Yours?

 

 

Sorry docc, I just saw this. Yes, both have minor play side to side and up / down. I'd guess about 1-2mm each way.

[docc]

I just compared the play to another V11 with 55,000 miles and it was much worse than mine (and suffering from the same*pop*-stumble). I still intend to tweak the CO but suspect that the shaft play is going to be a trouble-maker for all the higher mileage v11s.