So I've been messing with thi 89 hurricane 600 since I bought it, and me and her have been through alot of issues together, some my fault, some her fault, and alot were the fault of her ex owner. (He didn't deserve her)

but here we r a few years in and still running strong with a couple residual issues.

Now this bike has been wrecked, chopped striped. And nothing has ever really gone right, I'm trying to change that. But keep in mind. I don't have a tachometer or speedometer. I do run a GPS app to check my speed.

I've done a TON of carb work, bought a second rack, replaced all broken and missing parts and stripped out ports that someone put a bolt in instead of I pilot screw
and painted it white

I have installed a factory pro carb kit, set of 3 mains to try and different needles. (I have the middle main jets in, I can check sizes when I'm home) These guys used this bike to win in the AMA so I'm taking their advice on anything.
also installed factory pro timing sprocket for advance

take it out on the highway and it seems to RIP. Runs great
chopped off exhaust screams through the window of every car I blow bye. 1-5 strong pull, goes great, hit 115-120 no issues, touching the rev limiter once and awhile.
AS SOON AS I HIT 6TH GEAR, complete loss of power, any any throttle position, it has nothing instant loss of speed.
pull the clutch rev her up, running great. Drop clutch, samething, no power
hit the choke, no change
ok, so I'm missing something gas, air or spark. Right?
take it home, thinking coil or wire under stress is failing
do acomplete stick coil over mod, start it up, must have done something right, running great
straight to the highway and same thing.
so I know it's not plugs,wires,coils or pick up sprocket.
so gas? I have removed the fuel pump, we've been riding dirty without a pump for a couple years now tho after burning through a couple cheap ones. So that shouldn't be it...mabye tho with bigger jets, faster consumption. Mabye
but...when I lose power in 6th, I cand drop back to 5th and run full throttle without skipping a beat, so the fuel has to be there!!!!
mabye air restrictions, someone did drill the airbox on the girl. Pull the air filter same thing. No change, so cant be air.
so...jets, my old arch enemy on all my bikes.
do I just need bigger or smaller jets, is that effecting my top end? But no, because my top end in every other gear is fine...runs great at full throttle in 5th
Sorry for the rant, I don't have anyone who understands this **** to talk to
but what do you guys think
try bigger jets this weekend? Order and Add a fuel pump just to test? I'm kinda at a loss
I'm gonna check carb boots next time I pull the carbs
there is also a kind of lag, or chop, in between no throttle and really getting on it, like it stuttttters for a single second.
is it at all possible my CDI?
or am i just asking too much of this bike.

 

Unless someone has modified the wiring, the engine doesn't know what gear the bike is in - the only control is how wide the throttle bodies are open. 5000RPM in first or 6th makes no difference - power output is the same.

Top speed is only 138mph - so at 120mph you're almost there. I think you're expecting too much from a bike which is probably only delivering 80hp at best on the redline.

 

The fuel pump is there for a reason. They starve for fuel at higher RPMs. Your relying on gravity and fuel head pressure (amount of fuel in the tank) to feed the engine when it needs the most fuel. Also float setting can be involved in fuel starvation. I would put a pump back on the bike. You could top the tank off and try it but still may starve.

 

so more gas, the awnser is always more gas.
lol
I've been considering the pump, I think I'll try that and a larger jet size.
I'm tearing it down now anyway for a subframe rebuild and rear shock upgrade and raise my seat height a couple inches

 

The chop between throttle opening is usually cause by the transition between the pilot jet and needle rising. The two fuel supplies need to match fairly precisely so there is no loss or gain in incoming fuel. If the pilot is too small, there is a lag until the needle volume picks up the slack. Conversely, if the pilot is too big, too much fuel comes in as the needle rises and can cause a studder. Also the pilot screw settings can cause this if not set correctly.

 

Another major issue besides having to have a fuel pump to keep up is the change in pressure in the airbox compared to the carbs. Your frame holes being open to a ram air effect always causes issues with the Hurricane's carbs. The faster you go, the worse it gets. This is due to the carbs receiving a positive pressure on the inlet side and a negative pressure on the ambient side, causing the fuel to be all out of wack. remember carbs work on airpressure and air leaks. If the reference air pressure is different from any of the other inlet pressures it works like crap. My Cane, while more moddded than anyone else's and owning the drag record for the F1 for more than 20 years, never just fell on it's face until I tried to make a ram air system for it for extra power or unless I got my carbs dirty through storing it over the winter. Dirty carbs show up everywhere in the rev range, so that's not it for you.
The ram air was so persnickety I could never get it happy for more than a day. Pressure change, temp change, weather change, whatever would throw it all out of wack again with the ram air. If you streetfighter a cane you have to block off those air inlets through the frame, PERIOD. Once you do that, take a holesaw or unibit and drill about a 50 holes on the backside of the airbox underneath the gas tank near the seat side. It has to draw air in from a low pressure area. If you drill any holes to the front of the lid, where air can be rammed in, you will need to block the front edge of the tank off to keep it from coming in.
Before I re-geared it for better drag times I took it to the Ogden Airport for highspeed days in 2004. I got a RADAR verified top speed of 164.7mph in 6th gear through the standing mile with all the mods in my signature except the handlebars. The handlebars happened in 2015 when I hit my 40's after I kept getting my wrists and forearms cramped up.
When I first started modding my cane it had 81whp. When I was done with the all motor build, running on C16 race fuel, it was 128whp. Pump gas was 105whp.

 

Thanks alot for the info buddy
I'm definitely like what your thinking
I'll block off the air intakes today and order a stock fuel pump
I'd love to pick your brain some more! I want to build this bike up as best I can