About Float Height and Carb Rebuild

[Kijona]

Adidas sent me some #40 pilot jets for my 97.

I was just wondering if I'll need to set the float height again if all I do is just rejet? I've never done it and from what I can understand, it's pretty difficult.

Shouldn't need to so long as I'm careful...? 

[NickyNumbers]

no reason to change float height. 

[adidasguy]

40's are what the rest of the world uses. No need to change anything. 37's in the US just made it leaner when idling to lower emissions
40's give nice power and smooth running in the 2k to 3k rpm range. Less use of choke, too.

[Kijona]

40's are what the rest of the world uses. No need to change anything. 37's in the US just made it leaner when idling to lower emissions
40's give nice power and smooth running in the 2k to 3k rpm range. Less use of choke, too.

Sorry, I didn't mean change. What I meant was do I need to "check" or "re set" it?

[adidasguy]

No change in floats or anything when changing from 37's to 40's.
Simply be sure things are where they normally should be.
37's to 40's is pretty much a "don't need to do anything else" type of upgrade (well, not an upgrade. You're just making your bike run like it does everywhere else in the world.)
Only thing is maybe adjust idle screw since the idle will be slightly richer.

[Kijona]

No change in floats or anything when changing from 37's to 40's.
Simply be sure things are where they normally should be.
37's to 40's is pretty much a "don't need to do anything else" type of upgrade (well, not an upgrade. You're just making your bike run like it does everywhere else in the world.)
Only thing is maybe adjust idle screw since the idle will be slightly richer.

Okay, let me try one more time.

Does taking the carbs apart (i.e., removing the floats which has to be done to replace the pilot jets) disturb the float level? In other words, if I remove the float will I need to set it again? Or does it hold its setting pretty well?

Edit: I just don't know how sensitive the level is on these and I've never set the float height before.

[adidasguy]

Be gentle and you should be fine. Should be OK if it is OK now.
Never hurts to check it anytime you remove it.
My point was that you don't need to set things to anything different than they normally would be.
When I put in the 40's in Trey, all I did with the floats (and I did put in new needles and seats only because I had them, old ones were fine) was to be sure they were OK. I knew Trey had a bad previous owner and my the carbs were farkled with because the screws were thrashed. I made sure they were set where they should be as per the normal carb specs.

[Kijona]

Be gentle and you should be fine. Should be OK if it is OK now.
Never hurts to check it anytime you remove it.
My point was that you don't need to set things to anything different than they normally would be.
When I put in the 40's in Trey, all I did with the floats (and I did put in new needles and seats only because I had them, old ones were fine) was to be sure they were OK. I knew Trey had a bad previous owner and my the carbs were farkled with because the screws were thrashed. I made sure they were set where they should be as per the normal carb specs.

Alright, I just thought maybe I was being unclear or something, heh. No offense meant!

I'll check them anyway. Just to be safe! Thank you!

[Kijona]

Just out of curiosity...is #37 pilot jet the reason why the older GS seems to lag a little when you twist the throttle and why there seems to be a dead spot at around 3-4K RPM? Though, that's a little irrelevant since the carbs operate at % of throttle and not RPM...

Just seems like my 97 has a kind of flat spot at about 20% throttle while taking off. My 07 doesn't have that dead spot.

[adidasguy]

Trey runs pretty smooth with the 40's. Junior always was good. I haven't opened him up because he does run good. He is Canadian so probably has 40's.

So I would say yes - 37's give that dead area. 40's work so much better.

[Funderb]

ta-daaa:




if you are worried, this worked out for me, my floats were WAY out of spec, for no real reason.

[The Buddha]

If the floats are set right then 37.5 to 40 is a swap without any other needed changes.
If its high it will choke and drown with fuel especially on hot restarts.
Floats need to be set with the gas level @ the top of the bowl with the carbs on the bike. I never do that 14.4 mm thing, I use a clear U tube for measuring.
Cool.
Buddha.

[Paulcet]

The procedure as described in the manual posted by Funderb should get you in the ball-park.  But, in my experience, it was off by quite a bit. 

To your original question:  Be gentle with the floats.  The pre-'01 float tangs are a bit thinner than those in your newer GS.  Then I would suggest you use the U-tube method to check the fuel level.

[Kijona]

Alright thanks for the information you guys.

[shonole]

Looks like the first thing I will be doing once I get the bike back together is checking the float levels with a tube.  I've been measuring it.  Didn't realize there was that much of a difference.   

[adidasguy]

You can measure float height with tubes with the carbs on your bench. No need to install them to do that. Hold them steady. Attach a small tube and funnel or something to hold a cup or two of gas about 6" higher than the carbs (that's about the gast tank height) and run that to the gas input.

FYI: If gas squirts out the carb air intake, then the floats are WAY too high or you have the gas supply too high. Remember: gas is gravity fed. Too high puts too much pressure on the gas and the floats can't close up. (Been there - done that - when I had a gas supply 3 feet above the bike. Lowered it to 1 foot and all was OK and could check the carb floats.)

[shonole]

You can measure float height with tubes with the carbs on your bench. No need to install them to do that. Hold them steady. Attach a small tube and funnel or something to hold a cup or two of gas about 6" higher than the carbs (that's about the gast tank height) and run that to the gas input.

FYI: If gas squirts out the carb air intake, then the floats are WAY too high or you have the gas supply too high. Remember: gas is gravity fed. Too high puts too much pressure on the gas and the floats can't close up. (Been there - done that - when I had a gas supply 3 feet above the bike. Lowered it to 1 foot and all was OK and could check the carb floats.)

Once again, you come to the rescue.  Makes perfect sense.  Another afternoon project for me!

[Kijona]

  Maybe someday I'll come down and help you. Got a couch for me to sleep on? LOL

[shonole]

Lol.  I'm sure I can work something out!