Mikuni RS Flat Slider Float Bowl Vent

[kiwisuzuki1100nz]

For those that race do you do anything in terms of hosing for the float bowl vents? The carbs come with float drain hoses but the float vents are not supplied with hoses.

 

[Duckndive]

Never bothered with anything on mine 

[Gixer1460]

Depends on if you use a full fairing and / or an airbox! This is the stuff that affects fuelling that can't be replicated on a dyno.

[Lachie04]

 For nz you have to run anything that could leak  to a small catch tank. Seen everything from coke cans up check the regs 

Edited January 5, 2021 by Lachie04
Getting old can't read

[kiwisuzuki1100nz]

Full fairing, no airbox (Pods).  Yup saw Motorcycle NZ rules state it cant be open to atmosphere.

Bugger better make sure I use oversize tubing as would not want to obstruct the vent and affect the float bowl fill rate. Will run them, into the same catch can for overflow pipes.

Edited January 6, 2021 by kiwisuzuki1100nz

[Lachie04]

@kiwisuzuki1100nzto be fair 10.13 only refers to oil and oil mists which takes into account the air box drain but since you don't have that maybe you could check with your clubs tech rep or rider rep to get a call on that. Most track days don't go to that depth of checks, my experience, is only comp events. I suspect that there are some local interpretations which is why MNZ clarified the classic's requirements for shark fins and engine catch tanks.

[Lachie04]

Hey @kiwisuzuki1100nzdid you ever come up with something for this 

Looking for some inspiration for fuel drain catch tank

[HWB]

Curious to know what are the benefits of running hoses vs not running them...performance wise i mean 

[Lachie04]

@HWBthere's no performance thing is a racing regulation to drain fuel float bowls and breather over hear. Which means a catch tank needs to be lower than the carbs to work and not a lot of space to do that

[HWB]

5 hours ago, Lachie04 said:

@HWBthere's no performance thing is a racing regulation to drain fuel float bowls and breather over hear. Which means a catch tank needs to be lower than the carbs to work and not a lot of space to do that

Thanks for explanation, say what now!? 1460 said it was a fueling thing that cant be replicated on the dyno thats why i asked. Cheers

[dupersunc]

9 hours ago, HWB said:

Thanks for explanation, say what now!? 1460 said it was a fueling thing that cant be replicated on the dyno thats why i asked. Cheers

if you have high speed air flow around the vent, it can cause a depression around the vent tube, which can change the level in the float bowl, and how the fuel is drawn up the main jet. You  don't get the high speed air flow on a dyno.  You can get the same effect on poorly designed airboxes. 

[Dezza]

10 hours ago, dupersunc said:

if you have high speed air flow around the vent, it can cause a depression around the vent tube, which can change the level in the float bowl, and how the fuel is drawn up the main jet. You  don't get the high speed air flow on a dyno.  You can get the same effect on poorly designed airboxes. 

To eliminate this potential problem, for those of us that do not have to route the pipes to some sort of catch tank, what length hose has to be fitted to each vent spigot?

[dupersunc]

9 hours ago, Dezza said:

To eliminate this potential problem, for those of us that do not have to route the pipes to some sort of catch tank, what length hose has to be fitted to each vent spigot?

Most bikes won't have an issue, it's really only when you start pissing about with airboxes.  I'd avoid running pipes on them unless you a specifc problem, or the rules say you have to, in that case run them into a bottle tucked away in the beely or behind the fairing. the length of hose has no bearing on anything in this case.