My guess is that this is a carb model. Could this possibly be a fuel restriction not allowing the carb bowls to fill quickly enough when the engine is under load i.e. the fuel fills the bowls slowly when standing or at idle but once it is running it empties. Possibly look at the fuel tank petcock for restrictions (is it a vacuum valve?) or sticking floats or float valves in the carbs.

 

Thanks for the reply. It does have carbs and I ran a can of SeaFoam through the tank about a month ago and that seemed to make it work a little better/cleaner. Although all signs do seem to be pointing to a fuel issue, aside from maybe the battery being low. But I could be mistaking the bike no getting any fuel for a battery issue. This particular bike has 2 gas tanks, an upper and a lower connected by a hose. It simply depends on gravity to run from the top tank down to the bottom tank (Which I suppose is technically the reserve tank. Since it runs on gravity it doesn't have a petcock (At least not a traditional one you switch from on to reserve). The second time I got it to start I ran the throttle up to 2500RPM and it sustained the RPM's for close to a minute with no hesitation. That being said, my 200lb ass wasn't sitting on the bike trying to make it go either. As for your question about the valves I'm not sure if you mean the valves in the head or the petcock valve, but I do know the bike has hydraulic tappets for lifters, not sure if that makes any difference or not, but I've been told they tends to last longer and require less maintenance/adjusting then regular valve lifters. The bike has always backfired while the choke is on warming up, but it has never backfired (Not once actually) while accelerating in any capacity. Once warm, it won't backfire while idling, but it will backfire bad from engine compression or simply letting off the throttle. I've always wondered what was causing that, maybe it's related, maybe it's not.

 

You can test the battery with a multimeter to see if it is producing the correct amount of voltage. (About 12.3 volts just sitting) While you are at it, you can also test the voltage at the battery with the engine running at about 3000 rpm to make sure it is charging. It should be somewhere over 14 volts.

 

I'm actually going to pick up a voltage meter today and give that a try, thanks!!

 

Also make sure the battery connections are snug and that the battery itself is strapped tightly to the motorcycle so it doesn't move around when riding. Those two things can cause any number of intermittent electrical problems.

 

The valve I was referring to was the fuel tank tap. Some bikes (not sure about yours) use a vacuum fuel valve at the tank which opens when a vacuum is applied to it i.e. only when the engine is turning over. I have heard of them sticking closed or partially closed causing fuel starvation. The popping you hear when you close the throttle (on the over run) is fairly common when the bike is running aftermarket (more open) pipes or if it is slightly over fueled or running slightly rich. Not necessarily something to worry about unless it is a full blown backfire which may suggest a timing issue. I even get popping on the over run on my Triumph Tiger which is a fuel injected triple but this is due to the aftermarket exhaust I run on it.

 

Interesting. The backfiring I get is more just popping. I thought it might be more serious until I heard it backfire yesterday just before it died. That backfire was the real deal, it sounded like a shotgun. It way different from what it normally sounds like.

 

In case people are wondering. It ended up being water in the carbs as well as poorly tuned carbs. All is well now, I just need to replace the damn stator.

Thanks to everyone for their help!!