Jetting mods

[ian.z9]

Been using my FJ1100 for work as usual and enjoying the better lighting after doing the relay mod.Runs great with standard pipes and airbox.Took out my Yamasaki for a ride and noticed slightly rough running around 3k in top gear.If you gas it from there there is a slight hesitation and then its off to the redline with a nice kick at 7k.Engine is a 1992 fj1200 with standard carbs with foam filters.Exhaust is a 4into1 with a gpz900 damper.I raised the needles one clip and then used a wee washer so its at 1.5.Never touched the pilot jets and I went up one on the mains.It ticks over great and really responds quickly to the throttle.I dont want to lose any of the feeling it gives just need to clean up the spot at 3k.What should I be starting to fiddle with? Jets ,needles or mixture screws (They are 3 turns out.) I can live with the problem but if there is an answer out there from you FJ experts I would be grateful.I like the Yamasaki so much I'm building another but with more modern wheels and brakes.But my FJ1100 takes the biscuit for long trips.Love it.

[Grey runner]

I have absolutely no idea what the answer to your problem is but I Seriously like what you have built, it looks like a factory special.    

[Country Joe]

I have absolutely no idea what the answer to your problem is but I Seriously like what you have built, it looks like a factory special.    

+1 That bike is spectacular!  What chassis is it based on?

[movenon]

Nice bike. +1
George

[aviationfred]

I have absolutely no idea what the answer to your problem is but I Seriously like what you have built, it looks like a factory special.    

+1 That bike is spectacular!  What chassis is it based on?

Looks like a Kawasaki Z-1 with a FJ motor mounted.

Fred

[ian.z9]

The bike was a z900A4 but after 160,000km the zed motor was past its best so the FJ was squeezed in.There are a few FJ/zeds here in Holland.Handles ok with the zephyr swinging arm but not as stable as my FJ1100 of course.My next one(I have a z750e frame for that) has FJ forks and an exup front wheel so I'll fit R1 blue spots too.I like Kawas and Yams so this is perfect for me.Just need a good heater in the garage as I'm sick of freezing .

[turbocamino]

 Not sure if the taper of a stock needle matters..or of its adjustability limits...but at 3 grand,you are into the needles..personally...i would raise them some....worked for me.

[~JM~]

Extremely good looking bike!

Almost has a Street Tracker vibe to it. Real nice!

~JM~

[Joe Sull]

You've got a great eye for what looks good on a bike. I was poking thru the iankawa collection and the "fastbike" is a real gem of a machine. I like what you did on the fj11 fairing. How are the head cooling cowls mounted to the fairing?

[andyb]

Start with a known condition.  Throw a synch at it, fresh gas, clean air filters, and reasonably cleanish carbs.

Stick fresh plugs in it, and take it for a cruise.  Hold it right where it stutters, run it for a bit there, then killswitch and yank the clutch in so the motor stops.  Pull off, and check the plugs.

If it's running poorly at steady throttle at 3k rpm and the gear doesn't seem to matter (though you may notice it more in the lower gears), I'd suggest going up a size on your pilots (to 42.5 from 40).

If it runs okay at cruise, but snapping the throttle open makes it cough, stutter, and fall on its face, you've probably got a lack of fuel in the bowls and will want to experiment with the float height (1mm change at a time).

I'd wager it's the former problem, as you have opened the breathing up without significant change to the idle circuts.  You can try bringing them out to 4 or even 5 turns out, but it most likely will not be enough adjustment.  Also they are little bastards and clog really easily, which is why I suggest starting with knowing that they're clean.


And I agree with everyone else, that's a damned cool looking bike.

[airheadPete]

Speedblock paintjob please! That is one great-looking bike!

[FJ_Hooligan]

Check the plugs.  If any of them are black you may have seeping needle seat o-rings or a high fuel level.

[ian.z9]

Thanks for the advice.I'll get the spanners out at the weekend.
I cut the lower section off my FJ1100 (Its got a 1200 motor) because it was damaged and made a simple L shaped bracket that bolts to the oilcooler fixing on the front frame section.I dont have the inner piece or the left side intake.One day I'll find one.
The black FJ1100 "fastbike"was at Spa in Belgium for a CSBK race. FJ engined bikes were 1st,2nd and 3rd by along way on the first lap.Much to my Kawa riding mates disgust.Ha Ha.It had a bored out xjr1300 block and was making serious power.

[ian.z9]

Wicked FJ 1300+. Ze germans have lots of money for toys like this.XJ 900 fairing fitted looked ok too.