1150NakedHawk

Hey Superhawk peeps,
I have a 98 Superhawk that is bored out and used to run great. Not sure what was the issue I stated doing research and found out that the RR on these tend to fail. Upon inspection some of the wires were corroded and not connected to my RR. So I replaced it with a better one from an R1.
The same symptoms are persisting.
When I open up the throttle it acts like I have a rev limiter at 5-6,000 RPM's. But sometimes it will give power over that, but not a smooth solid powerband.

Getting air fine, I'm pretty sure it's getting fuel because it backfires often when I let off the throttle.
I don't know if I need
- to open the gap on my spark plugs
- replace the coils
- get new stator
- or something else.

Anyone else have this problem, I'm guessing that I am not the first to experience this?

Thanks,
Michael

7moore7

Check out PVLIR first... small vacuum line on your petcock (on the bottom of your tank) should be at the back of the petcock facing sideways, not on the little vent nipple facing down.

How and when did the issue start? Quickly or gradually?

Stator is likely fine IMO
Plugs are less likely as well if the onset of the symptoms was quick.
Check (bypass) kickstand switch to make sure that's not causing any issues)

8541Hawk

Did you take the tank off?

If so it's a good chance it's PVLIR...... where do you have the vacuum line to the petcock hooked up? It should be on the side not the bottom.

8541Hawk

Trained you damn kids too good....lol plus us old guys type slow....

7moore7

It's just training. Like Forest Gump when he assembles that rifle...

1150NakedHawk

Petcock, Check
I had put it on the bottom, and now checked it and moved it to the rear of the adjustment, and it now is on the back side facing the left.

I was hoping that would fix things, it pulls strong until the 5k mark and then hickups til 6k then pulls pretty string there after. Havent reallly opened her up.. i just did a 6mi loop down the highway but it is rush hour here.. only got into 4th gear and 95 km.

Anyone know what could be the cause of this hickup?
I dont have a **** or handle on my petcock, so I turn it completely one way for OPEN and the opposite for CLOSED. is that correct?

1150NakedHawk

7Moore7

This started a little while ago( few months), maybe when I ran out of gas. Ever since it has given poor response at higher RPM range. I've run fuel system cleaner through it, but have not taken out the jets and cleaned or replaced them. I'm wondering how difficult that is and should I have bigger jets cuz it is a larger bore and sucks down fuel?


I laid the bike down riding too soon after snow and hit slush and sand in the road. I've since installed a new air filter, new plugs, new coolant, oil and a right crankcase cover.
Starts right up and goes.. I also replaced the RR.. It was doing all this before I put her down, and I thought replacing the RR was going to solve my problem.. but not the case.

Putting the vaccuum hose on the correct spot did give me a cleaner power band and rev.. but still sticking/choking at 5-6k RPM

thanks
Michael

8541Hawk

The diaphragm might be cracked or going bad or possible sticking.

Try seeing if it holds vacuum or take it apart and inspect it for damage.

7moore7

A side question... you've had relatively extensive motor work done but haven't touched the carbs yet? Just trying to get a feel for your bike. Seems like if you were going to spend money/effort in the cylinders you'd also be looking at the carbs. They're not terribly too difficult to work on and remove or replace jets, although tuning for a more than stock motor I have no experience with and could take quite a bit of time.

I'd start with checking petcock diaphragm like Hawk said. You may have caused an issue running it with the vacuum line running to the wrong nipple for awhile.

None of the bikes have a **** for the valve FYI (I think a key to turn it came with the OEM tool kit, but I never had that either). It's supposed to be always on unless for some reason the petcock isn't functioning or you're storing the bike for a long time, then you turn it off.

8541Hawk

There is no ****, you use a 8mm wrench to turn the manual shut off and yes one way is open and the other is closed,