Intermittent power loss
I'm having some trouble with my 2005 VTX 1300C that's driving me freakin' crazy. I can't find a pattern, nor can I pinpoint the issue, I only have theories. I'm hoping one of you guys have had or heard of this before and can help me out.
My bike, at times, falls on its face when I crank the throttle more than about 50%. It doesn't matter which gear it is. As long as I'm just cruisin' around I can ride just fine, but if I have to pass someone or accelerate hard out of a turn (interstate on-ramps) the bike just hits a wall and acts like its being physically restrained. Downshifting only makes it worse. HOWEVER, about 25% of the time I'd say the bike is perfectly fine and pulls hard through all the gears and >50% throttle makes it pull even harder (as it should).
For example, if I'm riding on the interstate at 70 mph and I need to pass someone, if I gradually open the throttle the bike accelerates but at some point of the throttle position the acceleration levels off, AND the bike will not go over 80 mph, even with the throttle pinned. Then there are times that the bike pulls hard from 65 mph well on past 80 mph and feels nice and strong. And, as I said before, this "wall" I hit happens no matter which gear I'm in, so it's purely rpm based.
I've cleaned the K&N air filter, done an oil change, checked valve clearances, checked spark plug wire tightness, changed plugs, dismantled and cleaned the carb, and replaced the regulator/rectifier (unrelated--it was dying and needed done, but I figured I'd mention everything I've touched). The battery is new too, but, again, that's unrelated. I also changed the main jet in my Factory Pro kit down one size, but I doubt that would cause this problem, especially since it's a periodic problem. Also, the bike ran just fine for a long while after the swap. I can't figure out what the problem is. I thought for a while that maybe the regulator/rectifier was affecting the spark enough to cause higher rpm lag, but after the swap the bike is the same (only now it sits at 14+V rather than 12V when running).
The bike has just shy of 60,000 miles. Could I have an ignition coil going bad? Wires? Or is there something I'm missing that's obvious to one of you? I will say that when the bike is acting up, there's no sputtering or after-fire or anything like that. It just feels like I have some heavy load I'm trying to pull or something. Also, this happens no matter if the bike is cold or warm. Sometimes I'll leave for work and the bike is running awesome, then half way to work I twist the throttle and it falls on its face, then other times it's the opposite: runs like crap at first, then suddenly on the trip I can pass people with ease and the bike feels really powerful. I don't get it.
Thanks for reading. I really need to get this straight.
2005 VTX 1300C.................................................. ...2006 Kawi ZZR600 street fighter