Engine problems: falls off at high rpms

[the_finch]

A while back, I started a thread about my VR going bad, and the associated loss of power at higher rpms. I replaced the VR and battery, and it helped alot, but it didn't cure it altogether. I just took the bike out again today after working on it for a week and a half, and it was worse. Much worse. It loses power to the point of almost losing all accelleration at 7k, and don't even think about going into the 8 or 9k ranges. And something new for today, while idling at a light, the idle dropped down almost 400 rpm for a second, and then jumped back up. It did that a couple of times, and then would take off and "blaaahhh" out intermittently under load.

Here's what I have:
1997 FZR600RJ: 22k miles, K&N drop in air filter in stock box, stock carbs, Factory Performance 5 degree ignition advancer, stock coils and CDI, recently replaced plugs, stock header, yoshimura RS-3 carbon fiber slip-on exhaust can.

The previous owner neglected some of the important mechanicals, like shimming the valves (a 16K mile service item, sitting pretty at 22k without it done yet, but I'm fixing that this winter), replacing brake pads, making sure the brake lights and turn signals work, keeping the carbs clean, etc.

So I'm here trying to staighten out this mess, and I'd love some comments on what it could be. Do I just need a stage 1 jet kit? Do I need to re-replace the VR (after checking, of course), rebuild the carbs w/ new emulsion tubes (when I got it, needles got clogged with chunks of varnish with the first month I owned it), get new coils/cdi, or what? I'm thinking that it is something else electrical, but I just don't know for sure.

[thatkid]

I would say you are on the right track. If the valves go too long there is a risk of cupping. Then you need new valves and that's pricey. You could have an intermittent issues with your cdi or your coils. I would say switch over to the ford coil pack and see if that fixes things. You'll get a stronger spark with the conversion which always helps with proper burn.

It doesn't sound like you need a stage 1 with what you have. (slip-on and drop in). If you are going to swap the emulsion tubes you might as well get the jet kit while you're in there. I'm sure you'd eventually like to have a full exhaust system so the jet kit would be a preemptive strike.

None of the options are super cheap but the ford coil pack swap is the cheapest. It'll run you about 50-60 new or you can find junk yard parts for cheap. Emulsion tubes are 100 and a new CDI is anywhere from 75 on up from what I've seen. Also make sure you don't have any air leaks in the carb boots. That can cause problems.

A 97 is pretty darn new so I wouldn't think it's a cdi unless your vr took it with it the first time. Electrical gremlins suck. That's why I ended up getting a new car. Couldn't figure out why mine just randomly kept shutting off while driving.

[haunter]

lean is my guess. slip on and K&N is what the Stage 1 Jet kit for!

valve adjustment would help too......