OK, I've got an '04 F4i that I purchased with 4468 miles on it a few months ago. When I first got it the bike had been sitting for around 4-5 months and when I would get on it the power would cut in/out badly. Almost like riding a wild bucking bronco, but the problem was it wouldn't do it all the time. One minute it would run perfectly fine and the next it would be back.

I started running 93 octane,added fuel injector cleaner, and checked the battery connections and for awhile it seemed as though the problem had gone away. Every once and awhile when the bike was lower on gas (before light came on though) the bike would start showing signs of this again. I would stop and let it sit for awhile, re-fuel and check battery connections again (which were always fine) and the bike would run OK again.

The problem is now at 9k+ the bike still does this once and awhile and it drives me nuts. You can be going along at 60 in 3rd for example and pin it and it just won't go any faster, it will just start bucking. If you lightly accelerate it will go but if you try to go fast it bucks. Stop for awhile and re-fuel and it runs fine. Recently I've also started smelling fuel more when I ride.I'm wonder if this is associated with this.

My thoughts are it could be one of the following and I wanted to get some other opinions.

1) fuel pressure regulator
2) spark plugs
3) air filter
4) fuel filter

What do you guys think? Has anyone experienced anything like this? I thought it was solved because for about 3k of those miles I never had any problems and then it came back. I'm considering replacing all at once and seeing if that fixes it.

Any thoughts on this is greatly appreciated because it's got me stumped.

 

I had a similar bogging problem just like where you mention doing 60 in 3rd, when I put in a used power commander. it had some loose connections. i've changed out the power commander and it runs fine!
If it's that intermittent, imho the problem's more likely electrical than mechanical. loose connections can be nasty. things to check might be: fuse connections, including where the fuses are inserted- could be slightly corroded. clean battery connections by scraping them and getting them all shiny again. unplug the ignition wiring harness and plug it back (like you'd do if you put in a power commander. check wiring for bad kinks/scrapes. also check things like ignition coil contacts... can't say if the fuel smell issue is related.

 

I'd definitely check out the spark plugs and see if they're fouled up. The air filter won't hurt to check either I'm not very familiar with where the fuel filter is located, or very familiar with the fuel pressure regulator. The only fuel filters I'm used to are on my old '76 Honda with the petcock filter and in-line filters i added before the carbs.

This may be a personal preference, but the only reason I wouldn't work on all 4 at once is so I could precisely pinpoint the problem. It could be argued that if you mess with all 4 and get it working, then problem solved. I guess I'd just be curious as to what really was wrong. Just my .02