bogging down between 3 & 4 grand

[hoffman1]

i have an 82 xj 1100 and it has been bogging down when at operating temp.but higher r's are good and lower seem godd to.just midrange is killing me. i have rebuilt the carbs and bench synched them.set floats.run high octane fuel.adjusted idle/air 1.5 out and #1 cylinder seems rich. the other 3 are light tan and clean.#3 plug get sooty.any help woul appreciate it.

[Dad2g5]

Check timing advance. Trust me!

[jimboreeno]

Make sure your boots are seated well.

[TopCatGr58]

Hey Hoffman,

We need a bigger picture. Bike History would help. Is it new to you, been stored a long time, or you've had it for years, but just now having trouble?? What if any mods, intake/ exhaust?

Bench synching is just a start, you'll also need to vacuum synch them, and you'll need the YICS tool to do that properly!

Lots of things to check, are all 4 cylinders actually firing, have you tested the pipes with water spritzes once it's warmed up? IF #3 isn't firing well, could be ignition problems as well?

Dad2G5, nice try but the XJ doesn't have any mechanical advance parts, both curves are controlled by the TCI. But there is a vacuum sensor under the tank, and the hose going to it could be clogged, cracked, etc....worth a look!

How did you set the floats, and to what level? And when checking the plugs, are you just checking them after idling? Need to check them doing the throttle chop technique!
T.C.

[hoffman1]

82 xj 1100 sat for 7 years,new to me i am an old harley rider first japanese cycle.pretty nice bike i must say.anyway i set the floats to 23mm.4 into 1 bassani exhaust with header.air pods. i also meant #1 is sooty not 3 sorry for that.all 4 are firing nice and blue.new end caps,plugs.rebuilt the trans. i learned about the boost sensor the hard way but that is good.new intakes.triple cleaned carbs.it is only 1 cylinder that is rich for some reason maybe jetting. had factory air box before.

[hoffman1]

any help please !!!!!!!

[pggg]

Hoff, so No1 is too rich at midrange, the other 3 all ok, fuel level on No1 could be too high, float valve could be a bit leaky, slide needle may be notched higher than the others, slide needle could be a different size than the others, maybe an odd size emulsion tube ... also sparkplug cap, the resistor inside can be corroded, the wire to cap connection could be dicey, maybe just a dodgy sparkplug even..

[trbig]

A bench synch will get you close enough to get the bike started, but the only way to get them right is to actually synchronize them with a tool. A bench synch gets them all the same... but rarely are two cylinders actually the same once you get it adjusted. Maybe someone close could help you out so you didn't have to buy the tool, but it will help you in the long run to go ahead and get one.


Tod

[goldcoastguy001]

Check your timing advance and vacuum canister...if that is ok.....i know some will disagree but drop a jet size or lower your flooat height......if i was there to put money on it i would....cheers...

[hoffman1]

just wanted to update you on my progress. worked on the bike over the weekend.installed 125 mains aknd 50 pilots.also found the #1 carb pilot screw o ring torn.repaired all she runs light a raped ape.thank you all.