FJ1100 set lean but smells rich!?

[mr blackstock]

Hello all,

After much labouring to get the girl running reliably, I have a remaining issue that is really getting to me.  The carbs are set to almost lean, and yet the bike's exhaust smells heavily of petrol when idling.  The plugs are a good colour, the carb slide needles are set in the middle groove, the idle jets are 2.5 turns out, and she idles around 850 to 950 rpm.  When idling there is "popping" from either one or two cylinders, can't locate which.

The valve shims are all within range, new valve seats, new "O" rings, no air leaks, standard air filter.
From the research I have done, turning the idle screws out will make it richer, turning them in will make them leaner, but if I do that I will be outside what is suggested for the idle screws.

I am soon to be ordering a new oil cooler off RPM as the engine is still using way too much oil, about 1 cup every 200 kms, I can only guess the bike is burning it?  A fair bit of vapour comes out of the crankcase breather at idle, oily smell.

I think I am understanding why the PO parked her up in his garage and bought a new FJR1300....

[andyb]

Fer starters, turn the idle up to where it belongs. 1000-1100.

[mr blackstock]

when I increase the idle the bike races a bit.

Tonight I tried something different, it occured to me that perhaps the idle was adjusted to high, and letting mixture through as well as the idle circuit, so I have dropped the idle screw down, riched up the idle jet so the bike only runs from the idle circuit, just in case the carbs are a little out in sync.

[Pat Conlon]

Wait, don't do anything until you sync your carbs first. Once properly sync'ed, then make your adjustments.

[mr blackstock]

The carbys were synched not long ago by a garage, and they screwed it up royally.  They got the bike idling but the idle jets were at 5 turns out and the bike reeked of fuel.  So I bought a little synching device off ebay for around $12 and fixed it myself, sort of...

But, my solution worked!  No more popping at the exhaust and the idle has a nice regularity now.  Increasing the idle jet by one turn to 3.5 and reducing the idle speed screw worked a treat.

I will buy a decent sych tester and redo to get it just right!

cheers for the advice.

p.s I discovered that the business I went to for the synch did not actually have a bike mechanic on staff, just a car mechanic.

[Dads_FJ]

Nothing against bike shops, but they are one of the reasons I do my own work.  It might take me longer but I have better QC...  My son bought a bike which 'just had the carbs gone through by _______".  I sure hope not, because the linkage for the choke was missing a screw so only one of the four carbs was choked when when applied.  And that wasn't the end of it, they are CV carbs and they had one of the diaphrams installed wrong so the needle jet wouldn't rise in one.  And THAT'S not all either... This bike (1988 FZR1000) uses different size main jets for the outer  and inner pairs of cylinders, and they had THOSE mixed up.  But they included a 'dyno sheet' with their work.  Yea, the dyno sheet PROOVED the bike ran like shit.  They even had the GYSM for this bike, shame on them!  Needless to say, it's running much better now after taking our time with it.

Congrats on your progress!  And for what it's worth I use a homemade manometer made from about 6 feet of clear tubing with 2-stroke oil inside, seems to work fine for me.

[racerman_27410]

I just fixed my buddys 4 wheel V twin mule for him after he spent 300.00 at a motorcycle shop to have it "fixed"

they replaced his fuel filter...... 2.5 hours of labor + parts for "only" 300.000 dollars!

the real problem was crud in the float bowl of the carb .... it only took me 30 minutes to drop the float bowl and clean it and one little spec of crud out of the main jet.

Now its back running perfectly again... Imagine that!


KOokaloo!