FZRSupport: the FZROnline Archive

Hi all,

I have a grey import 1989 400rr I love the bike and it is very heavily modified (I will get some pics up soon)

I have owned it for 2 years and most of that time it has smoked black smoke when first accelerating hard or on hard throttle pull back. It doesn't affect emmisions. Or power, but at a constant speed it will pop and splutter. My mates seen to think a rebuild is needed. I'm tempted to de coke my pistons first. Do a fuel filter and oil filter change and re tune my injectors my bike doesn't burn oil and doesn't seem to be losing any. Do u think I'm on the right track or do u think rebuild

I'm thinking if a rebuild is needed maybe a engine swap.

Any ideas?

its injected? check the program might be to rich. if its carburated check jets and fuel bowl level. sputtering is most likely fuel related not mechanical

Sorry slip of the mind mine has carbs. I meant retune my carb jets

You dont want to have to rebuild the engine that will cost a small fortune, better off buying a used motor, or droping a fzr 600 motor in it.

To me this sounds rich and usually a good synchronizing session of the carbs can take care of that.

I don't particularly want a rebuild. I'm hoping to drop a 600 motor in more and more now. What would u recommend yzf600 motor or fzr600 motor

I thought a carb clean and set up for now would suffice tho and maybe a de cokein and fuel filter and oil filter change
What u reckon?

Unless you are talking "fox-eye" an FZR600 motor will not bolt-up (it lacks the upper mounts) and does not have proper counter-sprocket off-set, so you will want a YZF600 motor. The YZF motor makes better power anyway.

sweekster wrote:To me this sounds rich and usually a good synchronizing session of the carbs can take care of that.

+1 black smoke = too much fuel
grey smoke = oil
white smoke = coolant (or S#it loads of oil)

The Poms call the yzf600 a fzr600 too. AS RoadDogma said If you're putting a fzr600 motor in there the one you want is a 94 onwards, know as the foxeye.

Ok so I got two options a yzf600 motor or a 94 fzr600 motor

And adjust my fuellin on 400rr motor for the time bein

Sooty smoke = running rich. Is the tail pipe covered (inside) with black soot? Adjust / clean / troubleshoot your carbs.