Need CV carb help for a 98 Superhawk. (streetbike)

[StreetbikePimp]

Hello All,

I am looking for help with my street bike. I know this is a dirt bike forum, but this is the most technically experienced board that I know. I’ve tried to seek help from the local Honda dealer and other “bike boards”, but to no avail.

1)year/make/model

My bike is a 1998 Honda Superhawk, also referred to as a VTR1000.

2)conditions (elevation,temp,humidity if extreme,type of riding

Elevation is sea level, Current outside air temp is anywhere from single digits to 30 degrees. However, I’m working on my bike in my shed and have a torpedo heater running. Air temp in the shed would be about 55 to 60 degrees.

3)modifications (pipe,air box,motor)

The only mod is a K&N air filter. The bike is sitting on the bench with the air box and gas take off. I have an IV line set up to supply fuel.

4)current jetting

The jetting is stock with a 175 main and a 45 pilot. I don’t know the needle code.

5)running issue that is trying to be cured.

(In a nutshell) the diaphragm slides will not open up when I rev the motor. What should I look for? Also, how do diaphragm slides work? Is there a vacuum line that I missed?

History: Last summer, I discovered, that mice had decided to build a nest inside of my air box. I’m pretty sure that I ran the bike on various rides without knowing the nest was in there, and eventually sucked some dirt…pine needle…or some other foreign object into my carburetor.

I pulled the carbs, and cleaned out the main jet, the pilot jet, and any other passages that I could find. (I did not remove the pilot screw or the diaphragm slides at this time) I cleaned out the air box, and cleaned the air filter. Put everything back together and went for a ride. The bike will idle, but it won’t accelerate. Instead it coughs, stumbles, backfires and eventually stalls.

I pulled the carbs again and did a much more though all job of cleaning. I pulled every jet and the pilot screw. Sprayed cleaner in every passage way, followed by compressed air, and I removed the diaphragm slides and inspected the diaphragms for any cracks, tears, or holes. None found. I reinstalled everything and took extra caution to make sure the diaphragms were installed correctly. I used grease to seat the ring, and made sure nothing got pinched.

On the bench, the bike will idle, but when I rev the motor up to 8000 rpms, the slides do not open up. It coughs, stumbles and backfires. If I manually move the slides with my finger, one of the slides opens and closes freely, the other one sticks a little bit before it closes all of the way.

6)does the running issue change?affected by motor temp?better or worse when hot?better or worse when cold?

I have not noticed a difference so far, although, I have not done extensive testing yet.

FYI, My Background

I’m not an expert wrencher my any means, but I have had my carburetor off of my WR450 and DRZ400S at least a dozen times to clean and change the jetting and I haven’t ever run into issues there.

[Wayward Son]

either the slide spring is wadded up under the cap holding the slide down,the diapram is out of its groove or the cabr cleaner ate the diaphrams.

also with out the air box lid on the jetting is so lean the motor wont build enough rpm to raise the slides.

[StreetbikePimp]

Thanks for the feedback.

I'll put the airbox back on (cross my fingers) and go for a ride.