Individual Filters

[78yamahaman]

I have been pulling my carbs off and on so much lately I have decided to take my old air box off and go with the indivdual air filters. I know I need to up my jet size probably but the carbs have been rejetted already for a new 4 and 1 exhaust and I think they might already be big enough. Anyway the question I have is what do I do with the lines that are going into my air box. I have been told that I should plug the big one and leave the ones on my carbs open. I have been told leave all of them open, and I have been told to plug them all. Has anyone done this to their bikes? What should I do?

[xschop]

lines to box

According to GURU Prometheus, leave them open to atmosphere, which I did, Or put small air filters on them....

[78yamahaman]

Leave all the hoses open? Will that cause a vacuum leak? Where would I get filters that small? As you can probably tell I am a novice to this. Sorry for being so stupid.

[xschop]

all?

no, just the top ones on the carbs which are vent tubes

[egsols]

The hoses coming of the carbs on the upper tees between carbs 1-2 and 3-4 are your float vents. The float bowls need to breathe a certain amount and if you plug them the bike won't run for long.

The big hose vents your crankcase, again don't plug it or you will run up too much pressure inside the motor.

Route the carb vents to a dry place and/or put filters on the end. The last thing you want is crud getting into the carbs via those hoses. You can run the crankcase vent just about anywhere. Before the advent of PCV valves motors used a simple hose to vent straight down.

[78yamahaman]

Ok I have 2 hoses on my carbs which went into my air box. Then I have a big fat hose that goes to my crank case. Do I leave that hose open as well.

[egsols]

Then I have a big fat hose that goes to my crank case. Do I leave that hose open as well.

Yup!

[AlanB]

Hi Yamahaman,

The big hose shifts a lot of air in and out; Put a filter in it..... K&N do a neat one which fits in nice and is held by the original clip. Mine even jams in between the middle two pods!

AlanB

[78yamahaman]

Thanks guys for all the answers.