Hey Superhawk Forum members, I have a problem and I'm asking your help with my 'hawk....!

I recently had my 'hawk serviced at an OEM dealer here in the Twin Cities in Minnesota (that I will leave unnamed). My hawk was originally brought in for a carb clean, and overall inspection. It was running really rough idling, and would be "muted" until about 1/4 throttle. After 2 weeks, they finally told me it was ready to ride, and that they had cleaned and synced the carbs (which was the 1/4 throttle problem), and put new pads on my rear brakes. Naturally, I took it for test ride down the freeway.

Smooth idling: Check
Low end: Check (First gear through the parking lot was fine)
Low end power: Check. (Left turn out the parking lot to the stoplight)
Mid level power: Check. (Side street to the freeway onramp)
Mid to top end power: Check (Freeway entrance up to freeway speeds)
Top end power: FAIL. (Wide open throttle to max out mph)

Cracking the throttle at about 70 mph, it gained some speed to about 100/110, and then I felt stuttering, and surging. The bike continued to do that as long as I was Wide Open Throttle. As soon as I backed off a little bit, it would run smooth again, albeight with not as much power as I think it should. Usually, i can push it to 140 (indicated) speed, but it seems to top out at about 110-120.

SO, I brought it back and complained. After almost a month in the shop, and $550 in parts and labor, I would expect a bike that runs as designed. ESPECIALLY since I didn't have this problem before I brought it in. None the less, the service manager was positive it was a jet issue, since I have aftermarket cans (D&D), and an K&N filter. I disagreed that it was my jets that were the problem, since I would of had the problem when I bought it 3 years ago. The deal was, if we ordered a jet kit (DynoJet) and it didn't solve the problem, they (the dealer) would eat the cost of the jets and labor to install them.

A whole week later I get the call that the bike is together and has been ran. Result after second test ride? No difference. After returning to the service department, the manager now says I need velocity stacks, because there are none in the airbox, (he apparently missed the fact they weren't there) and that's the reason it's running this way. After a tense "discussion" over the issue, and my dissatisfaction, I rode away to have some other professional look at it. As I write this, I haven't yet brought it to someone else to look at it, or put it up on the dyno.

I'm reaching out to the Superhawk forum professionals with these questions: 1) Could this really be a result of missing Velocity Stacks? 2)What other causes do you think could be causing this? 3) Where can I throw it up on the Dyno in the twin cities for cheap to dig into this issue further?!

Thank you for the replies! I'll be monitoring this thread for further discussion! (And pictures of my bike coming soon)

 

What is that?

Yea, I'm sure that they haven't worked on a superhawk either ever, or in a very long time. I'm learning as well. It's good to know that it's not imparative that I have those on there...although I'm sure I'll have them put on now.

 

here is a link to some pics.the vacuum line must go on back of the petcock,not the bottom nipple.
https://www.superhawkforum.com/forum...ix-pics-19843/

 

the K&N filter does cause trouble with the bike.that could be a added problem to whats happening.
this might be a good start for your carbs to get it near correct.going partly back to stock will help.
will need the stock needles.
https://www.superhawkforum.com/forum...-set-up-24769/

 

Are the carburettor diaphragms undamaged and seated properly? You can do a quick check by pushing up both carb slides and releasing them at the same time. Neither should slam shut and both should close at the same time.

 

Thanks for the Info. I'm at work right now, so I will have to wait until I get home tonight to double check some things.

And, what do you mean about the K&N air filters causing problems? The shop said that they re-oiled the filter. Are you supposed to do that? I got suspicious when they said that.

 

They should be. They carbs were just cleaned by the dealers service department. Which, I know doesn't mean they were necessarily assembled together again right.

 

if they oiled the filter, then it is not OEM which is paper. That said, I made a foam filter out of my OEM and oiled it and it works great.

I'm curious about what RPMs all this missing takes place and in what gears?

 

the K&N filter on the superhawks tends to cause more harm than good,too much air flow.
its possible the needles and jets were put in the wrong places,or is not completely sealed or seated correctly.
too many variables.

 

No, they specifically said that it was not an OEM filter. They said K&N race filter. (I haven't been into the airbox/carbs on my own yet with this bike...but after this, I will be) so I'm not sure exactly which K&N part it is.

As for the WOT issues: It's not an RPM/Gear issue. It's only when the throttle is at wide open position (either slow speed as in taking a corner, or high speed on the freeway), and any gear. It doesn't miss or backfire. It just feels like it's gasping for air for a couple of seconds, then ok, then back gasping for air (or fuel, or a combo) until I roll back off the throttle.

 

Well...that's awesome. (Sarcasm implied)

And here I thought having K&N's were a good thing. I was actually thinking of trying to find out if there is an airbox eliminator kit, and just go to open pods. Perhaps I should rethink this...?? haha.

 

ohhhhhhh mannnnn,thats a whole other can of worms you dont want to open
the OEM filter will do the bike just fine,and for the love of god,just leave the air box in the bike the way it belongs.its been done and discussed,and 99% of the time,they all went back to stock airbox setup.
once you get in there and we could maybe see some pics,than maybe we can determine whats there and not there.

 

yeah k&n race is probably a good place to start. Like I said, mine is OEM converted to foam and lightly oiled and haven't touched it for years.....works great.

That said, it's definitely not a K&N which has proven to be notoriously troublesome when used in 90% of the superchickens. Slap an OEM in there and see what happens.

 

I'm going to get some pics up, and see what's really in there...and post them up. It might be a day or two...but I'm really learning a lot here, and I'm pretty excited to get this running like a champ so I can get back to doing wheelies. Err.....riding safely to work.

 

Your priority should be getting your airbox, filter and velocity stacks* fitted back to standard. Then you can begin 'tuning' on a dyno taking into account the exhaust can.

*Were the velocity stacks in there when you 1) bought the bike? 2) initially dropped it off?

nb front & rear stacks are each a slightly different length with a separate part no.

Ronayers.com Microfiche Honda>Motorcycle>1999>VTR1000F>AIR CLEANER

 

Umm yeah.... this is step #1. Without the stacks, it will never run correctly. Throw in the K&N ( at least IMHO) and I suprised it runs as good as it does.....

 

Yea, the funny thing is....I've had the bike for almost three years now, and never once got into the airbox, or carbs...and had it into a couple different dealers (only 1 did any type of carb work...and that was replaced the throttle cable, and re-synced the carbs) and the thing ran great. (apparently without velocity stacks) Now, after bringing it to unmentioned dealer that it's never been before...and after they cleaned and synced the carbs, and oiled the filter, the top end is terrible.

Now, I completely 100% agree with you guys, and I'll be tearing into it this weekend and taking some pics and posting them to find out what I can do.

My only question is: if I go back to OEM filter, won't I have to re-jet again? I have D&D exhaust, and as far as I know...they dealer put a dynojet jet kit in to try and solve the problem? What about when I add some velocity stacks (that weren't in there before)?

 

Ok guys...here are some pics I took of the petcock and the airbox/airfilter tonight. Let me know what you think. And yes, I know the velocity stacks are missing. My main question is: are the tubes hooked up to the petcock right? See anything wrong with the airfilter/airbox? Thanks for your replies.

 

The fuel hoses and vacuum hose are correctly positioned but the drain/breather hose, currently on the bottom of the fuel tap, should be attached to the appropriate nipple nearby on the underside of tank. (see below part no. 28 and the other drain/breather hose 29)

Ronayers.com Microfiche Honda>Motorcycle>1999>VTR1000F>FUEL TANK

Plus the absence of velocity stacks isn't going to help your cause. Were they absent when you bought the bike or have they been lost along the way?