I just purchased a 1998 Superhawk with 63k miles, Yoshimura exhaust and Dyno Jet kit. The acceleration seems choppy and lack of power? I have read about the bike lifting the front tire off the ground but my will not. Not sure if it is a v-twin thing but my VFR will leave the VTR in the dust. I have read a few post about cleaning jets and carb sync. I took plugs out and the front was dark (rich) and the rear was white (lean). Is there anything else I might need to look for besides the cleaning and carb sync.
Thanks,
David

 

Yes, also look at carb settings, jets, etc to ensure the rear is running richer than the front. This is done to keep the rear cylinder cooler due to the lack of airflow. Also, while it's open check the air filter.

 

I took my air filter out and started the engine. I am carburetor illiterate so if I do not call it the right name let me know. The rear slide opens when I turn the accelerator but the front slide did not open. When I took the plugs out the front plug is rich and the rear is lean. I ran the RPM’s up to about 5-6 RPM’s. Is this normal or how can I fix the problem?
Thanks,
David

 

well at least we know now why you've got so much vibration...a good carb cleaning is in order, lots of attention to the slides, examine the springs' action etc. Perhaps the carb gurus could chime in here?

 

Update: I took the front and rear vacuum chamber covers off. The front diaphragm has a hole in it, the rear is fine. I am going to order a new diaphragm and hopefully this explains the choppy acceleration and "lack of power"?

 

I temporary taped the diaphragm and the VTR pulls like crazy. I just bought the VTR and did not know the potential. I was going to sell it but now it is a keeper! Found diaphragms for $69.32 on hondaparts.com does anyone know of a better place to pick them up?
Thanks,
David

 

David. I think I might be having a similar problem. Im gonna look into my carbs this weekend... My VTR seems real weak. I mean my old souped up F3 could probably pull on it. Clutch wheelies will pull it up but power wheels take alot of work.

How was your milage before u taped up the diaphram? Im gettin about 28-30.

 

Just bought this bike so have not had a chance to test gas mileage closely however the last tank fill-up was about 35mpg. I have searched a lot of threads about diagnostic and "how to" about carbs. Cleaning, sizing, ect. I do not know a lot about carbs but thought it was time to find out how. I pulled the airbox and started the bike. When I gave the throttle gas one slide would not open and that is the one with a hole in the diaphragm.

 

Just got my new diaphragms in. The old diaphragms have an extra hole drilled in them from the Dynojet kit of the previous owner. What will happen if I do not drill the extra holes? What is the benefit of the drilled holes?

 

Fill the holes with JB Weld or 2-part epoxy and carefully sand them smooth.

The holes are specific to the DJ kit. If you don't have a DJ kit then fill per above.

 

The bike still has the Dynojet kit...I just had to buy new diaphragms because the old ones had slices (cuts) in them. I just wanted to now if it makes that big of a deal to drill new holes or just installed without drilling the holes? Does the Dynojet kit really need the holes drilled?

 

The rubber diaphrams don't get holes, or you'll be buying new ones again. The drill hole is in the slide.

 

Ah, now I understand. Yes, you should drill new holes. The kit is designed for them.

 

Thanks for the advice, I will drill the holes in the slides...I was just wondering what the benefits are?

 

The slides lift faster.

 

Nice...I am off to buy a drill bit.

 

Hey good luck with all of that, I can tell you that once you get that thing running right with those aftermarket pipes...... you'll always choose the VTR. I sold my VFR once my hawk was dialed in. Being a carburated v-twin it' craves maint, but 100x more reliable than a buell or Harley. 10x better than a Duke.
Best wishes!

 

Thanks for your comments...it encourages me to get it running top notch. I have Yoshimura exhaust and am thinking about removing what looks like a baffle. I will have to search to see if anyone else has done this?

 

It always seems to be the front diaphragm as it was with my case. Not sure why but it's interesting to say the least.

BTW, Honda's prices for a diaphragm on any bike is expensive; we're not special.

 

Hi David,
If you don't have the instructions for the drilling, this may help. http://www.dynojet.com/pdf/1185.pdf

 

thanks, that helps...just dont have the dynojet jeg for the slides

 

Just installed the new slides (drilled new holes) and went for a ride. The bike stumbles between 4500-5000 rpm...then it really picks up and pulls hard. The previous owner installed a dynojet kit...not sure what the jet sizes are? The needle jet is set at #5 slot. Any ideas? Thanks, David

 

I'd try raising the needle up a notch to see if that improves things. So if your #5 is the fifth notch from the pointy end of the needle, try the fourth notch.

 

I've followed the thread and enjoyed it. But what is the purpose of the slide lift hole in the first place and why is it advantageous to drill a third hole?