StrayCats GSXR 750 Problem - Only VRF Forum Guys seem to be helpful

Hey , I appreciate the advice, it wouldn't be the first time I did something wrong. LOL

Here are 2 better pics.

1st upside down, 2nd how I set the heights. Its a bit of a strange setup really. in pic 1 the floats are actually a bit lower (technically higher I guess) into that upper body than they would be when assembled, because the float mounting tabs are pushed down into place by the bowl when its bolted on. In pic 2 you see me pushing the float mounting frame into place in order to attain the correct float height (simulating the bowl being in place)

 

Yeah.... way to go Suzuki. Let's make the mounts out of plastic and require the bowl to hold it in the correct position.

No wonder they are a bitch.

 

just sayin.........

some manuals want the float measurement done with the float bowl gasket in place, probably .5mm to 1mm difference.

 

Looked at the online manual, doesnt say anything re the gasket but it does talk about inverting the carbs, which like the Capn' said seems WRONG. check this out , floats dont even show parallel to the carb body...

 

I think they are saying the same thing you actually did. "Invert" until the float arm is just in contact with float valve.

 

Yea, I guess, the picture doesnt jive with the proper way to do it.

im not even sure its physically possible to set them to the correct height the way the picture is, I just looked and you'd have to gain another 2-3mm on height and the tongue would have to be bent to extremes.

GSXR forum guy just posted and says carbs need to be fully inverted and if the floats are depressing the plunger then they need replaced. First time ive heard of this...nice way to go against the grain Suzuki.

im so confused....what to do, what to do

 

I've ran into that before where the sketch is not based on reality. But it makes you scratch your head and doubt yourself sometimes.

 

Yea, IDK, my experience tells me as soon as you fully invert the plunger will depress, even if the the needles are new (?), thats why its always tilt till it seals.

here what it still looks like following Suzuki's method :

 

That's the first time I've ever heard that, regardless of make. Sounds like some old "wisdom" that got perpetuated from a self proclaimed "expert". The manual says to invert, so they must be bad. If that was the case, the manual would say that. "Replace valves if button depresses during inverted inspection." They wouldn't say "just in contact" if you're supposed to just flip them and measure. They would definitely be in contact.

Either method, with valve buttons that don't depress under the float weight, and rotating until contact with "bad" valves will end up at the same measurement. Makes no sense. And ALL of my Hondas with "bad" valves shut off the flow of fuel just fine, and at the right height.

 

A couple times in the past when adjusting float height I've thought, "that can't be right". So I hook up a clear tube to the float bowl drain and loop it up past the top of the carb and let the carb fill up. The fuel will rise in the tube the same height as inside the bowl and you can do a real visual inspection of how full the bowl is.

 

Well, ill be damned. bare with me here...

So....Suzuki says go inverted, GSXR forum guy says inverted and plungers shouldn't depress inverted, and everything ive seen / done in the past says tilt only and never invert.

With the original needles and seats, I can get 14.7mm using the tilt and can only get 13mm or so inverted.

So out of curiosity I swapped the original needles and seats for the new K&L ones I had issue with and guess what, the float assy sits way higher with the K&L replacements, over the 14.7mm required and the measurement is identical whether or not I tilt them or invert them. --- WTF ? so now I adjusted the float tongue to 14.7mm using the K&L's again

All 4 are now sealing normally, no air passing by.

Comparing the original needles to the K&L needles, there is a small difference in construction but nothing really noticeable in overall length


So now I gotta wonder about the running issue - here are the steps as it relates to float height

1) Originals needles /seats, ran like shit, dropping cylinders - definitely floats were way off and likely flooding as the were under 14.7mm leading to too high a float setting

2 ) K&L, ran like shit and flooded out due to needles and seat on cy #1 which MAY have been due to a poorly installed seat (crooked), but other cyl were struggling and all the manifolds were wet. float height with K&L at this point unknown but likely better than step 1

3) I put the originals back in and adjusted the floats UP to 14.7 using the traditional method - they were significantly less when inverted - didnt run the bike

4) So now im back to K&L with the correct float height of 14.7 by REDUCING the float height slightly -- I have no idea how close or how far off heights were in step 2.

I guess the only thing to do is put them back in and try again

if that fails ill pull them back out , and go Original needles and seats and set to via traditional method.

 

problem with these BST carbs is, no nipple on the float bowl to attach hose to FFS.

 

i do that routinely on all my carb repair jobs, takes alot of time but it gets a critical measurement verified.

 

It's definitely not Suzuki-universal to fully invert the carburetors when taking the float measurement. I know that because I learned it the hard way with a 2002 Bandit before I knew any better about needing to tilt the carburetor and take that measurement. I was overflowing the bowls until I redid it.

I'm hoping these float height adjustments you're doing now are the ticket.

 

I dunno, but I believe you are misinterpreting what they mean by "invert". The way I read that manual page is to have the carb with float bowl side up, "inverted", but to have them on an angle where the float seats the needle, but is not depressing the plunger.

 

Yea, I hear you guys, and I can see that it can be interpreted that way too.

Im also hearing from the GSXR forum Carb guru's to INVERT INVERT INVERT with these BST carbs (?? IDK, im trying to balance good advice from you guys who I trust with advice from someone who im not as familiar with but appears to know the GSXR)

So, now though, if I'm getting the same 14.7 mm measurement tilted with the initial air seal AND its the same reading fully Inverted, im quite perplexed.

The only reason it would be the same reading in both positions (in my simple mind) is if the plungers were weak in the old needles and they are firmer in the new ones. ?

-------------------

IDK

I guess I'll try it and if it shits the bed again, ill pull them back out and put the originals back in and go with the tired and true "tilt" method

Stay tuned guys, and by the way I DO REALLY APPRECIATE the advice and sounding board you guys give me here. THANKS FOR THAT

 

Popcorn


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I believe that what you are going to find, its that there is a flat spot or seam on the float that is going to be running parallel with the base of the body when the float is adjusted correctly and held at the right angle.

 

NC does it show that in the manual?


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It would appear there is more than one carb guru at the GSXR forum....and he's saying to do the same thing being said here. It could very well be confirmation bias on my part, but I have never heard of doing it any other way, pretty much ever.

https://www.gixxer.com/threads/float-height.296594/