Ok so I took my Hawk on the road a couple days ago on one of those long Texas country backroads. I hit 130 , and then I feel as if I hit a governor or something, the RPMs dropped and it stumbled a lil. Then it picked back up to normal cruisong 70-80. On my return trip I tried to get on it again and the same thing happened around 90-100 the RPM's just dropped to about 4-5, after that it would go back to normal 70-80 like nothing. Any ideas? Dirty Plugs, Carbs? Thanks Fellas!

 

Have you done anything to the carbs? airbox? exhaust?

The thing that comes to mind for me, is that when the slides come all the way open, you come off the needles and it's all main jets.

Could you be too small on the main jets? Any pinging noises?

 

No, I didnt hear any noises. I just felt like the bike just shut off and the RPM's dropped to around 4-5. After letting off the throttle and letting it calm down I can get up again like normal highway speed 70-80. I just picked it up from the shop because I was a dumb *** and fixed a leak from my tank and then tought I hooked everything up right, but I had to pay $170 for them to hook up a petcock line up for me. Rookie mistake, but I couldnt figure it out. You mentioned you were working in Texas, whereabouts are you?

 

I'm thinking of a gas feed problem, check for a pinched gas hose, that the fuel petcock receive proper vacuum and proper tank venting also, you can usually hear a vacuum noise when you open the gas cap.

 

Mine started acting like this when the diaphragm in the petcock tore. Eventually got so bad I could barely keep up to traffic.

 

I'm in the lovely town of Granbury, TX.

Whoever planned the layout of this town must have a lynch mob after him.

Sure is warm though.
I wish they'd hurry up and start those gas turbines...

If you want to get really good at taking your tank on and off and adjusting your throttle free play, buy a jet kit. I didn't have a knowledge base, when I did mine. Just a long string of stupid questions for my friend Bob, who patiently worked me through them.

 

I second the idea of inspecting the vent lines from the tank.
Not sure if these bikes have a "tip-over valve" but check it if it does.
Sounds like you're creating a vaccum in the tank at sustained high fuel demand.
BTW, if you open your tank while it's still under vaccum fuel sprays all over you and the hot engine. Open slowly.

good luck.

 

a vacuum in the tank sounds legit to me...are you noticing any gurling/air gulping once you shut her down after a ride?

Also, could reversing the vent/vac tubes cause this by either messing up the diaphragm seal or sucking junk into the vac line?

 

my bike has shut down on me twice on the freeway for no reason.....starts right back up, or just drop a gear and pop it back on. seems to be a "normal" thing for this bike.

 

Tank vent.

 

Running out of gas at high load, WOT conditions is a sign that your bowls are emptying. You have a fuel flow issue, sir. Check that the petcock is open, that you don't have PVLIR (search the forum), and as a last resort that your fuel strainer on the petcock is clean.