Fuel screws closed...still fuel on the boots!

[eak0703]

Hey all,

I'm trying to tune a potentially messed up pair of carbs and here's where i'm at:

Before, each float was way below 15.5mm and the engine was getting flooded with gas. It would start and run on 2 cylinders (2 & 3 would fire)...cylinder 4 would fire every other time...and carb 1 didnt fire at all.

Each time I would pull the carbs there would be little puddles of fuel on the intake boots. Also...there were droplets of fuel coming OUT of the engine exhaust!! (i don't have the pipes on there..so i could observe the drops right out of the engine body)

I went back and ajusted float heights to 15.5mm above the bowl lips...this was a little tricky. They didn't want to go up that high. Got it with a little tinkering though.

Went back out...same issues.

Too much fuel. Already my fuel screws were maybe 1 turn...maybe 1 1/4 out. So i decided to just close them completely.

Wiped everything off...fuel screwes were closed (tightened all the way)...put everything back on the bike...craked it a bit. Pulled the carbs off....same puddles of fuel!!! what gives? is this supposed to be? Its as if eveything i'm tuning makes 0 difference!

So...i'll mention that there was also a "no-spark" issue...because all the plugs got soaked. only plug 1 was alive. I cleaned the plugs with carb-cleaner. dried them off...tested each on..and tested each of the wires...they all now work and i can see little sparks jumping on the plugs when i ground them to the engine.

Spark issue aside, when i close off the fuel screws and crank the engine...should there be gas going in at all???

Thanks in advance guys

[arsenic]

why the F did you put them at 15.5mm, thats problem #1. BTW the pilot screws have 0 to do with fuel in the air box, thats all floats. The correct float height is 14.6mm

[brooder]

If the floats didn't want to go to 15.5 mm, wouldn't that be an indication that you're doing something wrong?

[arsenic]

you would think

[eak0703]

Guys...basically, the floats wouldn't go to 15.5...

i know..stupid move...thought i saw 15.5 in another thread...went back to look and it was actually 14.5

but..since the floats didnt go up to 15.5...they basically are at 14.5 (its only a millimeter..and i couldnt actually get the floats to 15.5)

the thing is, there was no difference before...when the floats were lower..and after i raised them. Still too much fuel.

[arsenic]

still, pilot screws have NOTHING to do with that. If float heights are right, then it's a stuck needle valve. You say "just a millimeter", you know ask a machinist if 1 mm is a lot. I could park a friggin boat in 1 mm. That's a whole lot.

[Londob5]

still, pilot screws have NOTHING to do with that. If float heights are right, then it's a stuck needle valve. You say "just a millimeter", you know ask a machinist if 1 mm is a lot. I could park a friggin boat in 1 mm. That's a whole lot.

Looks like you're gonna have to get a bigger boat!

[arsenic]

yeah
if I could REALLY park a boat in 1mm, I would certainly need a bigger boat

[brooder]

As a note, on the 98+ the float height should be 13.0 mm +/- .5 mm. Is it the same for the pre?

[arsenic]

no, pre is 14.6 +/- 1mm

[eak0703]

Just double checked all of the floats. looks like they are all at 14.6mm

I will try to start the bike tomorrow morning now that I have also made sure that: each spark plug has spark and that each of the 4 spark plug wires work.

I guess I was completely confused and though the screw controlled the flow of fuel. Since it controls the air...this changes everything. I had those screws open maybe 1/2 turn...less probably.

When i saw that too much fuel was getting into the engine, my immediate reaction was to close those screws...in reality i was just oxygen starving my engine. Amazing that it ran at all!

all 4 of those screws were @ 1/2 turn out..and all the floats were off. It would still start...run for a while until the spark plugs got too soaked...then would die.

Hope tomorrow yields better results.

[brooder]

I would try opening the screws to a reasonable setting for any further testing. 1/2 is was to low. I'd set them at 2.25 (I think that's what I saw for pre...having a 02 makes me wrong a lot, though).

[eak0703]

Well...same results today. Floats still at 14.6mm

Opened the screws 2.25 turns out from being all the way closed.

Spark plugs were all in order..

Bike did start, only carb 3 was firing. Blueish exhaust and again drops of fuel dripping out of the engine.

Giving a little gas got the rest of the carbs to fire, but only for a few seconds. After a small amount of time the plugs must have become fouled cause the engine died.

I've taken some pictures. At this point i just can't tell if its me doing something wrong. or if there's something really wrong with these carbs.

I know the problem is in the carbs. I have a 2nd 96 Kat 600 that I ride daily. This winter i took the carbs off that bike and was able to run the engine on this one without problems. This rules out electrical or compression problems (i think)

If anyone has any suggestions/advice...i'd surely appreciate it.