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Carburetor General question

ralphie

Ralphie Boy
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I am just getting into this 750 Honda. Would it be wise to lose that air intake box and put on 4 KN filters? What is the take on that being that it would be easier to work on your carbs?
Ralphie
 
Once you start changing Intake (airbox/airfilters) and/or Exhaust you most likely need to re-jet your carbs. Keeping everything stock is easiest if you can.
 
You should definitely keep the airbox. I tried the pod filters, they don't work nearly as well as the airbox.
And I had K&N pods. Your carbs need the constant velocity provided by the airbox.
 
Yup, those Honda engineers knew what they were doing. When messing with such things you may be able to increase hp in one area of the rpm range, but loose it some place else.
 
I had a problem whereby holding it steady at 60 mph it would chug and almost stall so I put a fuel additive In and gave it a good fistful which seem to sort it out. That resulted in the rpm increasing to 1200 and I cant find the screw to slow the revs .Only minor aggro as I am not standing ticking over much at all.
 
Idle speed screw is under carbs and exactly in the middle of the two pairs. You get your hand under where the hot parts can get you real good.

CV carbs (if it has them) do NOT like more jet, and why so many screw up yanking the airbox to do four. When you jet richer the slides drop and they have already dropped some from yanking the box. Bad way to go. The carbs all open faster and higher when they share common vacuum and why the box is there.

Pick up a physics book kids.........a carb only feeds fuel for 25% of the time the engine is rotating, or 180ish of 720 degrees in a complete single cycle. It is then down inactive and the vacuum in it drops like a rock. if you share the vacuum from the other three though, one of which is always sucking, then the ones sitting dead do not lose nearly so much vacuum effect, ergo, the slides lift higher and faster. Pods allow the off line carb to die like a dog.

Ain't no magic there, just solid engineering principles in action.
 
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Thanks amc49 Much to my peril I found the screw you refer to, but due to fat hands and a hot engine I failed to resolve the frantic idling speed. It runs fine nevertheless and today has been fine and warm so I took to the hills Clent Hills to be exact and high up there the revs eased a little. Its been 4000 miles since a service so I took the air filter out to have a look see what state it was in but it was fine though on a trip back from Ireland I was hitting some high speeds and when I checked the oil at home it was off the stick but it took very little to top it up.
 
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