Topic: 76 cb550 float height question

[prov431]

on my 76 c_b 550 with pods and carpy exhaustA, 42 Slows, 115 Mains I have been playing with the flow heights. on my last adjustment I Lowered height a little bit in the bowl and I noticed my top speed dropped off Some, But BikE Ran VerY Nice. How CriticaL is float height 2 overall running eficiency.... should I open them up again and raise them a little? apologies for the poor grammar, I'm on my mobile

[lucky]

There is no good reason to play around with the float levels.
Just set them with a measuring tool like the workshop manual shows and leave them alone.

Floats were never made to tune a motorcycle.
All a float bowl does is make sure the engine can get enough gas even while leaned over
going around a bend in the road.

Lowering the float level will just cause problems.

Do you want the engine to sputter and run low on fuel while going around a curve on the road??

[flybox1]

As you've discovered, small changes in float height will have an effect on engine performance.
The primary purpose of the float is to maintain a certain fuel level in the bowls.  This level is optimal for the engine.
If you are tuning to your exhaust and intake modifications, jetting and needle clip position changes come first. 
Set your floats stock height for now, and dial in your jetting/clip settings/AF mix screws.

[prov431]

the reason I Adjusted Is because I found Them All at different Heights when I took the carb rack apart... I also found the synchronization way off and Got Both Adjusted beautifully... the bike is running incredible! I only have 1 single issue to fix the number two bowl is dripping fuel and still must be just a tic hi... I need to double check the nEedle and get some new screws for the bowl... I replaced all of the orings, so I know that's not a problem. is there an easy way to measure 22 millimeters with the carb rack ofF?

[lucky]

I would remove the float bowl and look at the brass overflow tube with a magnifying glass for a vertical crack. The crack in the brass tube can be soldered.

You did not say where the gas is leaking from.

IF the float needles have not been replaced they should be.
If they are all metal then you need to replace the needles AND the seats.
If the needles are rubber tip style then JUST replace the needle.

Many times when the needles are worn owners will try adjusting the float levels to get them to quit leaking. Then you have a mess.


What happens is the metal needles get worn from engine vibration and if you look at them with a magnifying glass you will see that the shiny ring on the beveled tip is actually a step worn into the beveled surface. IF the needle turns.spins then it may not be concentric and will leak. That is WHY Honda went to a rubber tip needle in later models. Engine vibration.

The rubber tip needles can get dried up and shrink and not be concentric.
So they leak.

[Romhog]

my 2 cents on float bowls on the 550 are as follows.
the first 2 times I had the carbs apart  I set the bowls to just touch the float using the vertical hanging method, of letting gravity set them, but the 3rd time when I gave up and did a complete carb rebuild I set them to the .22mm or (.89inches) this worked as designed, even though I changed my main jets up 4 sizes.
I would stick 100% to the .22mm.  the fluid vacuum calculations are based on that depth of fuel I believe.

I used a set of calipers (the inside pipe points ) to set my float heights

[prov431]

Thanks for the replies - and now that I'm on a proper computer, I can type!
The float bowl is leaking gas from the bowl seal area (where the o-ring is) I have a bunch of loose and a few mixed screws on the bowls because of the worn out threads...this is probably the issue. When I pulled off the bowl I held the float so the needle would be against the seat and I was unable to blow air through it...so it appears to be sealing well. I didn't have a leak issue on this bowl when I took it apart the other day so it's surely not the overflow tube just cracking all of the sudden...but I did remember that from a previous thread! I will adjust the float height just a wee bit, get some proper oversize screws for the bowl and that should do it.
I'm overly excited at how well the bike is running now - it pulls beautifully right off idle all the way to redline 9,000 rpm without missing a beat, also no hesitation at any rpm in any gear...just go go go! I'll have to strap my gopro camera on the tank and do a video...for all the grief I've gone through with pods, jetting, bowls and carb sync and general engine tuning it has finally put a smile on my face to see the bike wake up and perform!
I went to a local bike night the other day and had bunches of people checking the bike out - lots of compliments, it was cool!

[flybox1]

NICE SCOOT! 
i bet with a few new bowl o-rings and some tapped holes and new screws, your leaks will magically disappear