This may be the end...
 

Ok, so I got my used motor installed in my frame and got it fired up. It starts up and idles beatifully, however anything off throttle is poop. If you roll on the throttle it hesitates then stumbles up in the rpms. I do get a little valve pop periodically and it's not that it won't build rpm it just doesn't want to, lol. I am thinking of a few possiblities being bad or not enough gas, timing issues, electronics? Any ideas would be helpful. Again it fires instantly and the bike sounds amazing at an idle just can't do anytihng else with it, lol. Thank in advance guys.

Chris

where the carbs drained and cleaned when they where out and has the jetting been changed to match any exhaust you put on? also are the carbs synd?

is this without the airbox attached?

everything on the motor and carbs is stock. It was pulled from a good running bike and is complete in my bike. I have the airbox attached and the tank in place. I have high mount mig exhaust and it actually ran great on the last motor that was in the bike (until I spun a bearing). My old engine was stock as well.

Doesn't sound electrical, check and make sure the battery id hot and she has good voltage charging circuit.

Sounds to me as if the main jet emulsion tbes are clogged and need to be cleaned. If the bike /Engine/carbs set for 4 to 6 months with fuel in the bowls likely issue is gummed up main jet circuit.

the Main jet screw into tubes that also unscrew form the carb body. Remove the tubes and check/clean the little holes on the sides.

Yeah, I figured I would pull the tank and airbox and go through the fuel system a little. I am so ready to ride again I can't stand it. Thanks for the info. I gotta start somewhere right?

Ok all, I just got done pulling down the carbs and doing a thorough check and clean on them. I pulled the main jet tubes cleaned out the floats, but I have to say all these parts looked damn good. They are all looking brand new now and after putting everything back together (also drained my tank and put in fresh gas). I am still having the exact same issues. I'm really scratching my head here. I am off tomorrow and will start the day by testing the timing and then I figure I'll check for a vacuum leak but after that what? I feel lost from here. Any more input or ideas on where to look would be great so that I can try and get this beast up and running tomorrow sometime. As always thanks again for any help I receive.

Chris

Did you hook the vacuum lines up right? Make sure you connected the line to nipple on the back of the petcock NOT THE BOTTOM. If you checked fuel flow over real well I'd move onto vacuum before electrical.

I second the vacuum operated petcock connections.

already checked this. I am wondering if I have a vacuum leak elsewhere, anyone know is normal for vacuum on the hawk? Then I'll check timing and if it's not either of those I'll be lost, lol...

Try some seafoam in the gas. Mine was doing the same thing when I got it. THe bike had been sitting for a season and stumbling and popping was result of dirty carbs. Used Seafoam in my gas a couple times and runs beautifully now!

Ok, new question, I noticed in my manual that the 98-00 model has a few different electronics than the 00 and up. I have the harness for the new engine I put in and the modules are different (even different part #'s) could this affect the bikes timing and cause my issues? Not sure if there are any differences other than the shape and plugs on the two modules, anyone who may know would be my savior...

Yes, and yes. Fuel tank level sensor, engine temperature, and gauge cluster are the ones that come to mind.

hmmm, yeah, I was just hoping that the electronics not being from the same era as the bike may have been my problem.... we will see

Ok, well, I'm giving up, I have swapped the harness now with the newer harness that came with the engine, Of course I can't hook up the gauge cluster and I haven't hooked up any of the turn signal indicators, but all the sensors and control modules are all intact. Now I get no spark AAHHHH!!!!! I just don't know what is left other than dragging this thing behind my truck to a large field and going Office Space on it. It's been a good run I guess but I don't know that I will ever ride a hawk again... :(

Keep the faith and look for simple things first. check the mechanical timing, unplug, clean and inspect all the ignition connectors, make sure your carb boots aren't overtightened or cracked, try fresh plugs (even if yours are new), walk away when you get frustrated and go back later.
Good luck, Rob

Thanks for the encouragement, but this is the 3rd attempt to get a good motor in this bike, I have lost the fire to even want to ride my hawk again. About to go put a bullet in her head... :(

if you do ill umm...... bury it for you

Is it possible the emulsion tubes have been flipped flopped? Is jetting stock? Have you checked cam timing? In my experience, if your having problems you just can't lick, take it back to stock and start from there (unless it already is.). have you done a compression test and a leak down test on this motor?