fzr 1000 ru problem

[phonic696]

Hi, need some help/advice with a problem i am having.

I own an fzr 1000 ru 1993 model. The bike has only done 14000 miles as it has been in storage over half it`s life. The problem i`m having is this. When i rev the bike (standing next to it) the revs go up and down as normal and returns to idle. However when i get on the bike and ride, when pulling the clutch in after accelerating the revs are staying up, not good for the clutch. Having ridden the bike for 10 minutes or so, when i feel the downpipes number 1 & 4 are quite a bit cooler than 2 & 3. I can touch 1 & 4 but 2& 3 burn.

I have stripped and cleaned the carbs, countless times. The emulsion tubes are new and i replaced two of the diaphragms, so all four are perfect. I have set the float heights to 14mm with a cut out credit card and set the mixture screws 3 turns out as a starting point. I have replaced the coils with 2.2 ohm dyna coils and taylor leads. The original silencer has been replaced with an sp engineering end can and I have checked the jet sizes are correct in all four carbs (these are standard jets).

Apart from the revs not coming down after giving the bike throttle there is still an immense amount of power and cannot fault the acceleration. Should i have checked the fuel height as specified in the haynes manual? Are the jets right for the slip on i have put on? The exup valve is still in place and is fully functional. What could be causing number 1 & 4 pipes to be cooler than 2 & 3. Help and advice would be greatly appreciated. Thanks

[kolederacer]

Just curious but have you synced the carbs? They usually like to do this if it is getting too much air. You may try 2 on the mixture screw instead of 3. 3 seems a little high and would cause this. especially if they are not synced pretty close.

[Stig]

89-90 state 3 turns on air screws, later models like RU state 2.5

Check for air leaks around inlets, especially the carb to inlet rubbers. You shouldn't have to check the fuel levels of the floats are correctly set to 14mm it's the same thing. When you checked the jet sizes in the carbs, did the middle carbs have different sizes to the outer 2 carbs?
As above, balance the carbs

Have the valve clearances been checked?

[phonic696]

Thanks for replies. The carb inlet rubbers are new, so can rule that out. I did balance the carbs the last time I had them off, but will put the gauge back on at the weekend and check again. Would assume I would have poor tickler if they were out. Will set the air screws to 2.5 out and see what happens. Thanks again.

[phonic696]

Forgot to mention the jets are right 2 outer carbs different to the inner ones as per haynes manual.

[phonic696]

Hi, update on rev problem.

I have balanced the carbs to within microns of each other and put the mixture screws at 2 1/4 turns out, but my problem still persists. I checked the compression on all 4 cylinders and found 1 2 & 4 were reading 175 (too high) and number 3 165. I put some redex in the tank and have been out running it around to see if this would help, but no joy. I have noticed that when i accelerate and go to 5000rpm or more the revs start dropping back down like they should, when i pull the clutch in to change gear. But when at lower revs this is where the problem is. When sat at a junction with the bike in gear popping the clutch in and out brings the revs back down quicker than sitting there waiting. When i set the float heights to 14mm i found them to be much lower than this 12.5 to 13? The emulsion tubes i put in were .001" lesser in diameter which meant they went in easier than the old one`s came out? Any ideas?

All four cylinders are now around the right temps.