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stuck slider
markyb - 11/6/09 at 05:02 PM

I took the filter off my R1 throttle bodies to check the butterflies and noticed that one of the cv sliders (black plastic part) appears to be sticking when I blip the throttle

what is the best way to get this released - do I have to dismantle the TBs or can I use some sort of lubricant to get the slider to move more freely ?

cheers


Cousin Cleotis - 11/6/09 at 05:22 PM

are you sure they are throttle bodies and not carbs?

If they are carbs, just take the top off, and see what the problem is.

Dont lubricate them.

Paul


David Jenkins - 11/6/09 at 06:44 PM

If it is a carb, not a throttle body, then it may be a perforated diaphragm in the upper chamber. Alternatively, it may be that the lid and/or diaphragm isn't seated correctly and thus stopping the diaphragm from lifting as the vacuum increases.

Downside - diaphragms aren't cheap...


markyb - 11/6/09 at 08:14 PM

http://i21.ebayimg.com/02/i/001/34/ee/8e87_1.JPG

did a search and this is the best pic i could come up with to try and show the part I am talking about

if you look closely you can see the black slider at the mouth of each TB - only 3 of mine move freely when i blip the pedal


David Jenkins - 11/6/09 at 08:20 PM

One of us is confused - that's a set of carburettors, not throttle bodies!

I go for the perforated or badly sealed diaphragm theory...

Unscrew the cap off the one that isn't lifting (watch out for the very long spring on the slider) and check if it's seating properly. If it is, hold the diaphragm up to the light to see if there's any holes.



[Edited on 11/6/09 by David Jenkins]


brianthemagical - 11/6/09 at 08:37 PM

I'd go for TBs, the fuel rail, fast idle control, and FPR give it away. If they are TBs, not crbsm then it's exactly the same as the above advice. Whip the top off and see what it's like, there may be some fluid in them though.


David Jenkins - 11/6/09 at 08:39 PM

Whatever they are (I'm no TB expert) you still ought to take the lid off...


markyb - 11/6/09 at 08:40 PM

cheers (you would never guess I know very little aboute bike engines !!!)- will have a look to see if it is perforated (already took the cover off earlier to have a general look and it appears to be seated ok)


02GF74 - 11/6/09 at 08:46 PM

quote:
Originally posted by brianthemagical
I'd go for TBs, the fuel rail, fast idle control, and FPR give it away. If they are TBs,


I go for carbs.

throttle bodies are bacially a tube with throttle disc and injectors fitted. they have no need for any slider and needle since the metering of fuel is doen by the ecu.

the last geneeration of bike carbs had TP sensors and other accosciated gubbins.

here is a photo of TB yesterday.


brianthemagical - 11/6/09 at 08:54 PM

The early Yam bodies had the sliders, hence them loking like the carbs they replaced.

The first linked pic are deffo TBs, the fuel rail and injectors give it away.

The last pic, are CBR's, poss early 00s Fireblade. A better depiction of the point could have been made with GSXR bodies, which are, as you say, simply a tube.


David Jenkins - 11/6/09 at 09:07 PM

An afterthought - on my CBR600 carbs, each cylinder has a rubber hose that leads from its main venturi tube up to the top chamber - if that is split or otherwise not holding the vacuum then the top chamber wont be able to suck up the diaphragm, which won't be able to lift the slide.

I don't know if your TBs have something similar...


brianthemagical - 11/6/09 at 09:11 PM

The R1 sliders have the vacuum pipe thingy up the middle of the slider. Could it be full of kack?

Do they move by hand?


matt_gsxr - 11/6/09 at 09:36 PM

Early R1 look like carbs with the slider, but are throttle bodies. I think it was an attempt to speed up flow in the days before secondary butterflies.

With carbs you can take this slide out of the top. It is spring loaded and is pulled down by the vacuum. Open it up, carb/injector cleaner and see what you get. They shouldn't get dirty, so maybe your filter isn't doing what it says on the tin.

Matt