whoever speced out the float bowl screws at yamaha should be fired!!!! have it apart and it looks damn clean. will try to take some pics. if i dont see any crud, it will have me scratching my head! thoughts??

needle valve and valve seat are incredibly clean. no evidence of plugging. i need help guru's of the carb. have to get it buttoned up for a ride, and am scratching my head with my bike torn apart. not a good feeling

Every time I have a hard time starting my bike I turn the idle way up. Sounds a bit weird but it works for me. Sometimes it is simple. If it was running good before and the carb is clean and getting fuel and spark is good. I would try that. I would also make sure the wires are seated between the plug wire and the boot. If the end looks bad might want to cut back a little on it. While the boot is of a little dielectric grease would be a good idea.

Take one of the old screws to a hardware store, and get stainless allen heads to replace them. That's what comes in all the jet kits.
If you've blasted cleaner into the the jets in the bowl, and cleaner is coming out the other end of the passages(in the throat), then button it up and put it back together.
Last thing before hooking the fuel supply line to the carb, test the pump on the bike this time. When you turn the key to "On" without starting the bike, the pump should build pressure, which means it will be pumping fuel....so be ready to catch it. If its not pumping fuel, but the pump is clicking, then do what Kai suggested, and run a piece of fuel line from the petcock at the tank, to the carb inlet, and let gravity do its thing. If it runs then, you'll know the pump is bad.

thanks. i mentioned earlier that i tested the pump on the bench hooked directly up to my battery. it worked. i will try it back again once on the bike and have the outlet line running into a reservoir to verify. is there a quick write up on what parts of the carb should/shoudn't see cleaner? i thought i read to keep the cleaner away from some components??

ajbonner wrote:
thanks. i mentioned earlier that i tested the pump on the bench hooked directly up to my battery. it worked. i will try it back again once on the bike and have the outlet line running into a reservoir to verify. is there a quick write up on what parts of the carb should/shoudn't see cleaner? i thought i read to keep the cleaner away from some components??

I mentioned the vacuum diaphragm in an earlier post(top half of the carb). There's also a diaphragm behind the coasting enricher(white cover on the side of the carb). Some cleaners have a bad effect on rubber stuff. Just blasting out the three jets in the bowl is all you need to do(make extra sure about the pilot jet). It's not like the old days of soaking the whole carb.
I only mentioned trying the pump again, to make sure it was actually pumping, and not just making noise. I didn't go back to read the post where you referenced the bench test, to see if you had hooked it up to a fuel source to see if it was moving fuel. You had mentioned that when you sprayed carb cleaner in the carb, it had started briefly. That would be a good indicator that it wasn't getting fuel. I'm just trying to get rid of all the possibilities as it goes back together.

Before I started delving into the carb needles and jets/ etc, I think I'd disconnect the fuel line on the carb and turn the bike over. Does gas shoot out of it?

I haven't read whether you checked the voltage on the battery, nor if you tried to jump off another battery. So until you know for sure, there is absolutely no sense to look anywhere else.
If you can't start the bike, only gas from the carb by twisting the throttle will only come out of the accelerator pump circuit, it can't come from anywhere else since all other fuel flow thru the carb is due to vacuum pressure, dead engine, no vacuum..period, no gas. So after all this time of playing to get it started, probably ran fuel below the level for the accelerator to pull, so now you won't see gas by turning the throttle.
So back to the battery, put a meter on it, or jump the bike from the car to confirm if it's the bat or not. A battery charger tells squat. unless it has a built in volt meter.

i haven't taken a volt reading because i dont have a voltmeter. probably need to go ahead and get one. i did however get it to fire up with carb cleaner. i dont think it is the battery.

any recommendations on a good solid multi-meter??

thanks guys for the continued advice.....much appreciated.

ajbonner wrote:
i haven't taken a volt reading because i dont have a voltmeter. probably need to go ahead and get one. i did however get it to fire up with carb cleaner. i dont think it is the battery.

any recommendations on a good solid multi-meter??

thanks guys for the continued advice.....much appreciated.

Take the battery down to Auto Zone or Napa, and they'll stick it on the tester for you to see if it'll take a charge, and or if it has a bad cell.