fuel starvation :(

www.bikebandit.com/PartsBandit/Assets/sc...1ZR750C1US_E1611.gif

this is my carb....
i don't recall having part 920050

is this just the vacuum attachment?

or is this the carb vent?

You wrote:

"1-4 are connected by a T connection that goes to the front of the engine. 2-3 are connected by a T that goes to the vac connection of the petcock. i think mine is internal venting."

I think the fittings you are referring to are VACUUM ports. These things must be plugged or connected to something. On later Kaw models, the hook up you describe is fairly typical. Normally, 1&4 are connected to a tee and the tee connects to the smog valve. Normally #2 is connected to the vacuum line going to your petock and #3 is plugged.

The venting on your bike is via holes in the sides of the carb bodies. The holes have a tee fitting and there should be a hose connected to your tee. The reason for the hose is so that if the bike overturns, gas won't spill out on the hot engine. NOTE that the vents MUST be unobstructed. The lines must not be pinched. These vents can vent into an airbox or hang over the swingarm but essentially, must be free to breathe or the float system will act funny... no gas or flooding... I will attach a pic showing vents and the vacuum lines.

Also, keep in mind, that even on prime, if the tank gas cap venting is obstucted, gas won't flow out of the tank. If the venting in the cap is partially obstructed, gas flow will be inadequate to keep the bike running but a trickle of gas might come out. The bobowls are just not filling.

Last, to check the fuel level, put the bike on centerstand but note that the front will be down some. Pick up the front tire and put a piece of wood under it to level the bike.

Thanks WG!

i had my carbs overflow through those vents i think when i left PRI on. wierd thing was i did the same thing again like a couple weeks later and it was ok. i guess the float bowls were workin.

i'll see if i have blockage in any of those tubes.
i don't even know if i did anything when i took apart the cap.....but i did make it smoother to turn the key to open the cap.

i just capped off 1-4. is it ok to leave the tube to the air suction valve open? or does it suck in air(cuz that may be the hissing noise i hear)

lol...never had this prob on my savage. 1 cylinder 1 carb 2 fuel hoses. but backfired like crazy on shutdown

Post edited by: tarheel365, at: 2005/11/01 10:15

Last time I had a problem like this it was caused by bad fuel reacting with fuel additives (octane booster) - it turned the fuel into "tapioca". The bowls were full of this goo and the only solution was to dump the fuel and start again. Filters did not prevent the problem, and in any event ended up being all clogged. Did you remove the bowls to see if something is blocking the needles/jets/passage ways?

By the way, if you are dealing with this kind of problem in the comfort of your own home, then consider yourself lucky - it happened to me in the middle of a rainy night somewhere on I80 in Iowa on a trip from Denver to Chicago.

carbs SHOULD be clean cuz i just cleaned them a week ago.

besides it runs fine. for the first 10-20 minutes then i start losin power.

the thing i hate about this problem is that i can't just ride around my neighborhood. i gotta go out on the bigger roads and hope it works or i'm stuck. i was fortunate that i got her started again though.

tarheel365 wrote:

carbs SHOULD be clean cuz i just cleaned them a week ago.
quote]

"SHOULD" is the operative word:dry:

If you get some bad gas, or gas reacting to an additive, or maybe whatever you used to clean the carbs with, then it could happen at any time - it's not an accumulation of dirt... you wouldn't be guilty of anything, like not cleaning the carbs properly - just unlucky:unsure:

that's true....
but usually if i have contaminated fuel, i can feel it in the acceleration and power during riding. or throttle response is off or idle is rough or bike is hard to start. in the first 10-20 min of riding....it starts and rides like normal.

but i have to drain fuel bowls anyway so i'll see whats in there:silly:

"i just capped off 1-4. is it ok to leave the tube to the air suction valve open? or does it suck in air(cuz that may be the hissing noise i hear"

I suspect it will be OK to leave the tube dangling. The vacuum actuated the air suction valve. If the vacuum is removed, the valve won't work. I personally would pull all the emissions junk off the bike. The air suction valve is connected to the cam cover I think and I think the cam cover openings will have to be capped/covered or plates added to cover the holes where they went. I think APE sells nice looking plates but not sure if they sell them for your bike.

i feel like an idiot

i forgot to take it off pri....fuel and oil got mixed so i had to change my oil and filter now i gotta get more gas.
also...
the hissing noise is from me not tightening the carb boot all the way. haven't had time to ride her tho.

Post edited by: tarheel365, at: 2005/11/04 00:06

well i don't think anything got fixed. i rode last nite for a test ride stopping every 3-4 minutes to see if my idle has dropped. about the 4th or 5th stop, the idle gradually dropped till the bike died. i pulled off the PRI hose and set the petcock on PRI, so i've got good flow from the tank.(as in understand it, a blocked fuel cap will cause pressure to build inside the tank thus neutralizing the vacuum of the engine, so PRI should not flow as well if there is vacuum in the tank)

i tried starting her up after she died but she just wouldn't start. even when the bowls were full and fuel tap on PRI and gas cap open.

when i went for a ride that nite when i believed everything was ok, i had also just filled 'er up w/ gas. i'm thinking i may have a problem w/ flow from the vacuum actuated fuel tap. but the bike shoulda started right up after restoring fuel.

can my compression cause this type of problem?

other than the fuel cap i don't kno of any other thing that can cause an idle drop after a short ride. and i still noticed a slight drop in acceleration before I stopped for the final time.

also checked the plugs *after* the ride so while the engine was hot. and i got fat blue sparks....which should mean my coils are ok.