2000 Superhawk with flat spot
 

Hi,
I have a 2000 SHwk. around 7000RPM or when you crack the throttle the motor bogs down as if not getting fuel. if you're a gentle with the throttle is doesn't seem so bad.

Two Bro's slip on
dyno jet kit 185 front 190 rear cilp at #5 per instructions
K&N
airbox cut open

seems to be all typical stuff.

I checked fuel, plugs, coil. any ideas would be appreciated.

nuff said...

exactly.......

any ideas guys? by the way I am at 6000' above sea level.

Though love from Tweety and Mike.

AKA, get a stock air box and filter.

There's ol' Tweet, being harsh on noobs again...

I'd suspect what you describe as 'not getting fuel' is actually the bike getting too much fuel and flooding out. First off, jets are way too big for that altitude, even with the K&N. However, what Tweety noted is also true: Go back to the stock airbox and filter. Doing that, you'll probably still need to come down to somewhere around a 180/182/185 sizing, even given your pipe considering you're at 6k'. I'm running stock (bafflectomized) cans and stock AF at just shy of 5k', and I went with the 172/175 setup recommended by Honda for high altitude, along with stock needles shimmed 2mm. Not sure of needle profile, but yours being shimmed way up sounds like a confounding problem as well.

+1 with Galaxie, you need to do what he says so you can get your setting back to a runnable baseline. It may still need small adjustments from there but until you do what Galaxie listed we can't really give you to much more to go on.

Oh and if you search some on airbox's it won't take long to find out that any modification to the vtr's box will result in disaster. Most people also have had better success with stock filters and carb tuning vs KandN although if you really want to retain the cleanable filter option BMC has a street version of their filter that I haven't heard complaints about.

The VTR is a harder bike to tune because of two factors. Large pistons suck in huge gulps of air along with large carbs make for the need for a really precise airbox design to keep airflow as smooth as possible in the ensuing storm of massive gulps, small changes make for dramatic and usually negative results.

As soon as you hear "flat spot" you know either or both K&N and Airbox are right behind it..

Don't mess with the stock Airbox, your ghetto mods will only mess it up and unless you have already modded the engine with thousands in pricey parts the K&N won't gain you any power and will make it harder to tune the carbs.

You can make a K&N work right, but it is usually more effort than it is worth. And 99% of the time you can NOT make a modded airbox work right.

+100!

Airbox is "cut open" it said...right?

Thanks GUys
 

Thanks for the help guys! I bought the bike this way and just trying to get it to run right.

I also have this bike and I love it. It is known in the U.S. as the SuperHawk, outside the U.S. it is marketed as the Firestorm. The looks of the SuperHawk are lean and clean. Not too much fairing to cover up the V-Twin powerplant, but just enough to shroud the twin radiators and provide some paintable surface.

Excellent forum contribution... Hope D2moto is paying you well. :p

went back to stock airbox and filter. Flat spot be gone. Thanks guys!