907 bogging above 2000rpm

[nickapaso]

Hello, I am having a problem with my 93 907 bogging above 2000rpm's. I pulled the plugs and they were quite fowled, soaked with gas and blackened. I replaced them and the problem persists. The more thrittle I give the more it boggs as if it is choking on too much fuel. When you throttle up and back it off a little it gets bursts of speed. I just took it to work and back today, about two miles. I run fuel injector cleaner quite regularly. It just started yesterday. Day before it was running like a raped ape. Now, not so much. Any help would be greatly appreciated. Where is the fuel filter on these? I'd like to replace that to be sure it is not something silly like that. The bike was recently rolled over. But it has run great for 500 miles since.

[DonaldoDuck]

The fuel filter is in the tank. Carefully remove the filler cap assembly and you can get to it. Make sure that the fuel level is low or drain the tank. A really good idea to change if you do not know when it was last changed..... But probably not your problem.

[Laddie907]

I had a fuel line blow inside the tank. [rubber hose between filter and pump]
the result was low line pressue to the injectors.
the bike would not run above idle.
there was a fair amount of back-firing, though...you don't appear to have this...

it doesn't sound like fuel starving if the plugs are wet; in fact - I'd check they are BOTH firing.

I'd also be inclined to check your TPS is functioning throughout the range.

[nickapaso]

it actually pops a bit when you are at neutral throttle between accelerating end decelerating. And when you let off the throttle all the way it backfires sometimes pretty loud. It just started doing that a minute ago.

[DonaldoDuck]

I had a fuel line blow inside the tank. [rubber hose between filter and pump]
the result was low line pressure to the injectors.
the bike would not run above idle.
there was a fair amount of back-firing, though...you don't appear to have this...

it doesn't sound like fuel starving if the plugs are wet; in fact - I'd check they are BOTH firing.

I'd also be inclined to check your TPS is functioning throughout the range.

I agree with Laddie the problem is not fuel starvation. A bad, loose or misaligned Throttle Position Sensor can cause these symptoms. Also, excessive fuel pressure, or potentiometer issues. A good place to start.

[Laddie907]

and just a note on the fuel filter...

the filter works even if it is FULL of crap.
my tank had corroded internally - lots of scale & rust.
we took the filter out and it was obviously heavy; cut it in half...it was full of solids. [ and I mean FULL ]

I'm not suggesting not to change the filters but that it's unlikely that the filter is restricting fuel flow. you can test the fuel flow by pulling off the line.

you can throw mega-bucks at trying to solve problems; putting in a new filter might be a solution but could just be an unnecessary expense.