[Glenn]

Stock 80" EVO. CV carb with thunderslide kit. Just installed a Kuryakyn 9990 Hypercharger. When I really romp on it I get gas in the Hypercharger. Pulled the trapdoor and reved it up a couple of times. Jet is pointed into the carb throat. Good spray patern. Can anyone tell me whats going worng?

[chucktx]

hey glenn, welcome to the forum.. i will try to help....the stream of gas from the acc.pump should be hitting the needle directly in the center of it.....not off to one side or the other.....it can be adjusted by carfully twisting it in the direction it needs to go.....let us know how you make out........
chuck

[kenfuzed]

I've seen this on a few hyperchargers and I have a theory (though not tested). At a given speed air flows into the hypercharger body and out through the back side where there is an opening. It's possible that a suction is created drawing fuel out of the carburetor back into the air cleaner. On a previous bike I had this was occurring, so I glued a piece of mesh (from an aquarium filter) across the inside of that rear opening. This reduced the amount of air blowing thru from front to back, and stopped the fuel buildup along with reducing oil being drawn in through the breathers.

Another cause for fuel spraying backward out the carb commonly has to do with exhaust reversion. When an exhaust pulse is allowed to pass back into the exhaust port its possible to continue to push all the way through the carburetor. Open pipes in combination with other components are prone to this, and just the right combo can make it worse. IMHO thunderslides often add to such problems.

One last thing to check... I've seen my share of thunderslides where the needle gets cocked of fails to fall into the closed position. This will allow fuel to spray up out of the emulsion tube unmetered.

[chucktx]

ken, your theory has good merit....didnt know the hypers were "flowthrough"...

[ironhorse]

I have been looking at the hyps. and corse air and force winder
most every one has told me to save my money on the hypercharger that it isn't all it claims for power gain but the best arguement they gave me was the vacume problems one is the butterflys don't always work properly and some modles when not working properly can cause a vacume. thats all I needed to hear the best filter setup seems to be the forcewinder / corse air style from what I have learned sofar

[kenfuzed]

The Hyperchargers work well but can have that "blow-thru" effect at high speed. What I like about them is they draw air from in front of the bike rather than from the engine side, giving you a true cool air system. I haven't looked at the new models so perhaps they already altered how air could blow thu from front to back. That opening on the rear-facing side is to allow air to enter when the flaps are closed.

[hotroadking]

Had the Hypercharger Pro series on my 95 inch motor never had a problem, Mike Rowland plays on HTT occasionally, they do work for many reasons, one is the larger filter area.

You can disconnect the flapper doors from the vac line and they will stay open all the time. No big deal.

I like the look kinda like a pro street car with the blower going through the hood, that's kool!

You can compare a standard Hypercharger to the SE kit in Flow ability, the pro flows more.

[Glenn]

Hey everyone, thanks for all the replys so fast. Last night I couldnt sleep and went out to the shed to take another look at this problem. I took a flashlight and looked into the trapdoor to see how the gas was spraying. When its ideling (which is alittle fast ) I dont see spray from the main jet. When I rev it I see what I think is too much gas. The spray is centered in the center post but seems to be hitting the black plastic thunderslide before it moves up.
Tried to adjust the screw in the bottom, turned it all the way in which I figured would stall the thing but nothing happened. Backed it out 1-1/2 turns to where it was before and nothing. Would welcome any ideas. And thanks again for all the replys

[kenfuzed]

The spray from your accelerator pump nozzle shouldn't be hitting the slide, but instead right under it as it lifts. There could be a couple things happening here.

1. Slide isn't rising correctly. Check if it has carbon buildup along the channels. Also check that the rubber diaphram is not pinched or cracked.

2. Nozzle is obstructed or damaged. Is the nozzle stock or the replacement version? A small amount of debis in the nozzle could cause the spray direction to be directed too far upward. It should spray directly down the lower center of the venturi. If the nozzle needs replacement let me know and I'll post directions on how to replace it.