MotoRacerGabe

I purchased a '97 XX this past weekend. Oh man, it's an awesome bike.

well, i have a little problem...
I noticed a little bit of black smoke coming from the exhaust when you rev it up really quickly. It does have a yoshi 4-2-1 pipe on it. I don't know if it has been rejetted since the pipe was put on or not. The bike bogs a bit until i hit about 4-5k rpms, but then after that it is smooth. it doesnt smoke at idle.

A couple of my buddies said it's running rich. i've read up and found out that black smoke usually means it's running rich....

okay, now what do i do to solve the problem? i have adjusted a carb before, but it was just one, not four. are they difficult to sinc? should i rejet? how can i tell if it's been rejetted before?

could it be something else making the black smoke?

thanks
-gabe

slyxdevil

you will most likely have to lower your needles one clip if its smoking and slugish up to 4k top end is strong front wheel comes up?

__________________
hard to steer when the devils driving,brakes who needs em they only slow you down
NOW ROCK ME UP TO 135!!

bartonmd

I agree...

fzrcbrklxrider

How much smoke is coming out ? just 1 little puff or a stream of smoke ?
It sounds like you already have a jet kit installed since it is running rich, A jet kit is designed to add fuel not take away fuel.
I would say it's not going to hurt the engine if it's just a little puff, but it woud best to get it taken care of asap like slyxdevil suggested lowering you jet needle's down 1 notch. is pretty easy & only take's couple hour's with the right tool's & intruction's ( clymer's repair manual)

Really the worst case senario is:
*It will cotaminate your oil with gas,
*Proven if an engine is run too rich soot/carbon will coat the cyclinder wall's & not allow oil to penetrate/stick causing engine wear, which obviously isnt good.
*Excessive carbon build-up inside your engine, Exhaust port's, valve stem's.
*Black soot on your rear cowl peice & muffler.

__________________
When exotic dancer's compete you win !!!

OZDave

Black smoke is fuel. Blue smoke is oil.
Running rich enough to bog down is putting enough extra wet fuel on the bore to wash off oil. It's not much of an effect but it does cause extra wear in the long run, and as someone stated can contaminate the oil.
Idle uses a separate circuit to the main jets. Midrange (and pickup) use the needles. Wide open only uses the jets. There is some cross over but this is the basics.
It seems like you have the easy problem to fix (Hopefully). Either the needles are worn or need to be dropped a notch.

__________________
Just because I'm paranoid doesn't mean people aren't out to get me!

MotoRacerGabe

Sorry it has taken me so long to reply... i was in the hospital. i got stung by a bee, i guess i'm allergic, I got a really bad infection and had to get antibiotics straight into my viens.... well, i'm out and okay now.... damn those bees. funny thing is, i got stung while i was riding.


well, i'm gonna work on the bird today.... hopefully get rid of that smoke.

in response to your questions....
after the bike gets past 4k, it does pull hard like it should. if i give it enough throttle the front wheel will come up.
the smoke is only a like a puff, it doesn't continuously come out.


thanks, for the advise. i'll let you all know how it goes

OZDave

WOW!
Great to hear you're OK. How unlucky do you have to be to get an infection from a bee? Usually has to be bad to get an injection into a vein. That has to be all your bad luck used up for the next year or so. The bike should be easy to fix now.

__________________
Just because I'm paranoid doesn't mean people aren't out to get me!

slyxdevil

wow u must be very alergic if its justa little puff you might be able to work it out with air screws but if not move needles

__________________
hard to steer when the devils driving,brakes who needs em they only slow you down
NOW ROCK ME UP TO 135!!

MotoRacerGabe

well, i still havent had a chnace to work on the blackbird. whenever i do have time i'm usually working on my vw bug. i'm gonna try and get to the BB tonight or tomorrow night. i am really hoping to. but now i may have another problem...

so i decided to take the blackbird out for a spin, use up some gas in the tank so it's easier to take off whenever i do decide on workin on it. i was riding for a bit and the bike was backfiring alot! it wasnt backfiring before this time.

doesn't backfiring mean it's running lean? i'm really not sure...

i am kinda pissed because i just bought the bike. maybe this is why i got it so cheap... but, everything could be fixed...

fzrcbrklxrider

When is it backfiring ? here are some option's : after you shut the engine off, while slowing down or down shifting, while accelerating ? This will help better pin point the problem.

__________________
When exotic dancer's compete you win !!!

MotoRacerGabe

it does it when i am accelerating. it doesnt backfire at all when slowing down
just now, when parked i gave it gas to bring it up to about 5-6k and held it there and itwas backfiring.

fzrcbrklxrider

Well definately sound's like you have a serious problem,
Sound's fuel related you might try taking the carb's off & cleaning them inside & out, blow all the passage's out with compressed air & carb cleaner (wear safety glasses it can get messy & you dont want that stuff in your eye's), If you dont have a air compressor, Go to the electronic's store & pick up a can of compressed air, or Wal-Mart they cost like $5 buck's.

Have you had a dead battery issue lately ? There is a small chance your problem is electrical the reason I ask.

__________________
When exotic dancer's compete you win !!!

MotoRacerGabe

i havent had any problems with the battery. i havent had any problems starting it or anything...