new member having some issues with my superhawk
 

Hello fellow riders!
Thanks for stopping by the thread.
Well I am new to the forum and new to my dear superhawk.
I picked her up as a bruised up, laid down bike from the tail of the dragon!
The previous owner hit a black bear on the tail.
After new forks, levers, pegs, and a few odds and ends she is looking like a bike again.
She was a strong runner stock exhaust, stock filter, hell everything looked in touched!
Well I.couldn't have that!!!
I turned the dual cans into a single outlet akropovic exhaust from a donor bike,
Replaced the plugs with iridiums,
Rotella T6 oil change and filter,
Flushed all fluids,
Replaced air filter with a k&n drop filter,
Romved air box to clean face of carbs and overlook parts under the air box for wear and damage!

Well it was time to fire it up,
Started fine, idled great!
Then I went to.give it some throttle....the bike was very hesitant and almost shuttered under throttle, so I let it idle back down tried once more same thing.
Soo I lifted the tank, removed the lid and filter to see what the carbs where doing.
Under throttle the sliders would hesitate and jolt back in forth under throttle it looked like it was getting to much fuel.
Checked all my vac lines everyrhing was in its place.
After messing with it I decided to remove the card all together to properly clean and inapec them for wear.
Removed the bowls jets looked great removed jets, floats, etc and soaked and cleaned them.
When removing the top of the carb to remove the slider and needle I realise a piece of the crank case filter element had been sucked into the top of the diapham.
I assumed this was the issues so I continued my cleaning and inspection removing both sides and soaking the necesary parts!

I installed the carbs today but before doing so I bypassed the coolant to the carburetors, and removed the 5mm bolt under the front intake boot and installed a brass fitting to help me dial in (sync) the carbs when I have the bike running corectly!

I plugged the fitting and.installed all vac lines.
I.fired it up the bike is doing thr same.thing like a hestiant shutter at throttle.
I held the throttle wot and the bike will almost die then rev up!

I blew out all jet ports, cleaned all parts thoroughly and inspected every piece of the carb when I had it out of the bike everyrhing was in spec.

I am not sure where to start on to the solution to this problem,
I have read through my Haynes service manual several times for this bike and nothing stands out of the ordinary!

Any solution, diagnosis, or ideas on what this may be please feel free to give it!!
I am all ears and looking for an answer!

I posted this on fore blades as well to expand my need for knowledge!


Thank you very much!

You left out some information... when you first bought it, did it do the same thing? I know it needed to be fixed up a bit before you put it on the road but im hoping you ran the engine when you bought it...

Second question, did you do any engine work what so ever before you discovered this running issue?

And lastly, welcome to the forum!

Thank you for the quick and first reply on the thread!!!
Yes the bike was run and reved rode around the block prior to tear down for routine maintance Its one of those "I fixed the bike" now it isn't running correctly type situations.
But yes the the bike ran fine before tear down.
I honestly feel it is a vaccum leak of some kind.
The carb sliders run of vaccum and they are very hesitant and shutter under throttle rather then a smooth slide they bare very jerky and fighting to open up when the butterflys do.
Sorry for the grammar typing this from a phone, I am at work.
Do you know or have a vaccum diagram for the carburetors?

As to engine work none just routine maintance.
Oil,
Fluids,
Filter,
Slip on exhaust,
Coolant by pass,
And installed plug for carb sync

I have a video of what its doing I just can't break it down into a format to put it on the fourm :(

Maybe the lines running to the fueltank petcock are not where they need to be. Common mistake when reassembling things

First guess the vacuum line going to the gas tank is in the wrong spot... it goes to the horizontal nipple on the back of the petcock

Thats a very common mistake, there are many threads on that one

If thats in the correct spot then my second guess would be you need a carb rejet and a carb sync due to the new type of exhaust, however i wouldnt think it would be running as bad as you make it seem in that case

I must of been still typing when you posted that one, my bad...lol

With the horizontal nipple..Yes I did make that mistake but the Haynes manual steered me straight.
Yes it is running quite rough compared to what it was.
I can manually move the sliders by hand and you can hear the diaphams compress and decompress with non issues so there is no blockage in the top of the diaphams there's.
The gaskets are all seated correctly with no leaks.
I have the air cut off valve pluged into its correct blank on top of the PAIR system.
All crank case breathers are in exact locations.
There is a breather on the far left smaller nipple it runs straight throigh past the rear head, takes a right under the coolant resivor then up the frame rail behind the right radiator (start buttom side of the bike) then t's off and and channles behind the oil cooler then to the bottom.of thr bike.
Dies that line plumb into anything or is it strickly a breather/ overflow line?

Thanks alot for your help!!

The line has no markings from a clamp or swelled end like it has been on something its just there, right next to the radiator, but OEM zip fasteners against the frame?

I didnt quite undsrstand that description about that line... there are 5 lines going to the gas tank, two are on the petcock for the fuel(very obvious), the third on the petcock rear most nipple facing hirizontally left is the vacuum to the carbs, then there are two more lines going to the tank itself next to the petcock, one is a vent line and the other is the overflow.. both of those run down to the bottom of the bike and are open(not plumbed to anything)

The bike is dumping fuel but the slides are not opening fast enough to compensate for it.

If you have a youtube, vimeo, photobucket, etc... you can upload it there and post a link

Okay then that answers that they are both vent/breather lines.
The way they have mine run through the bike is a very crazy way!
Yes the two on the far end of the tank one is a medium nipple and its lines runs straight down next to the coolant overflow.
the other is a smaller diameter nipple almost the same as the horizontal vaccum nipple on thr petcock.
And the way they have it run is all crazy through the engine under the carbs between the cylinders up the frame rail next to the rad then t's off and one end stays stationary near the rad the other end of the t routes down behind the oil cooler then pointed towards the ground.
Its in front of the other two overflow lines gas and water.

I am attempting the YouTube link now!
Great idea!
Hope my phone allows me to follow through with it!

I am at 10% and counting...this may take awhile!

:(

Let me know if it works!

Youtube
Search bar.
Vtr1000 carb/vacumm issue

Video is up
And able to been seen if anyone has any solutions ornanswersn

Bike isn't going to run the same without the airbox. With the intake so open, it's will lean out the mixture.

It was doing the identical thing with the airbox in place tank bolted down fully covered.
I pulled everything off semi can get a better idea of what the carbs where doing.

I couldnt see in the vid, is the rear cylinder doing the same thing?

Yes sir rear cylinder is doing the same identical thing!
Shuttering back and forth during throttle.

Is it getting equal amounts of fuel to each carb, and have you cleaned the petcock and petcock filter and checked the vacuum pump ? sounds like 1 cilinder is not getting a steady amount of fuel

I am going to tear the filter and petcock out today.
I disconnected the main fuel lines from the carbs held the tank over a catch tray and turned the petcock to the on posotion, equal amounts of fuel poured out.

Unless you had moments before run the engine, the petcock shouldnt pour fuel... it is vacuum operated and unless you put vacuum to it, very little or no fuel at all should come out...

I dont think this is your problem but if you pull the petcock apart look at the diaphram for tears...

On another note, i noticed in your video that you still had the vacuum line hooked up to the PAIR distributor or whatever you want to call it, how did you go about disabling the pair system?

Put a vacuum hose on the horizontal nipple of the petcock. Turned the valve to the on position. Crested vacuum and the flow came steady and equally!

The pair (pulse secondary air injection system) is between the front and rear cylinder head and I think helps with pressure and gasses.
The air cut of valve on the front carb connects to the blank on top of the pair system to prevent a leak.
I was going to elimate the pair system after I get this ossure resolved

Issue resolved with the carburetors.*

Sorry typing from a phone!