Kawasaki Motorcycle Forums banner

1 - 20 of 27 Posts

·
Registered
Joined
·
73 Posts
Discussion Starter · #1 ·
When I was a kid, I remember sitting in the drivers seat of a car that was turned off and my dad warned me not to step on the gas or I might flood the engine.

My question is, can you really flood a vehicle (car or bike for that matter) by twisting/stepping on the throttle while it is turned off? Are there any other damaging things it could do? Does carbureted vs fuel injected matter? I've heard that it only depends on whether or not it has an accelerator pump, but I have no clue what sort of bikes (or cars?) have them and whether or not that's the whole picture.
 

·
Powerhungry
Joined
·
38,189 Posts
anything thats fi, and off, the throttle wont do anything.
i think carbd bikes too, it wont do anything.

carbs vehicles, yes, as they have accelerator pumps, and will squirt fuel, everytime you hit the gas.
 

·
Registered
Joined
·
3,741 Posts
Actually carburated bikes are like cars... if you twist the throttle the accelerator pump will squirt and you can flood the engine just like a car.

But if its FI, it wont do anything at all... same with FI cars.
 

·
Registered
Joined
·
28,313 Posts
99% of bikes do not have accellerator pumps. unless you have something with FCR39s or 41s or similar badass carb rack.

the vacuum piston is what regulates airflow so the motor doesn't spin up too fast for the fuel to get pulled out of the emulsion tube. also why i drilled my slides out to make them pick up faster. thats why it works the way it does.

as far as damages, of course you can fuck some shit up. flood the motor enough and you can hydrolock a piston. best case, pull the plug and blow the gas out.. worst case, bend a rod and crush a bearing in the process.. also, gas will seep past the rings into the case and contaminate the oil making it thin and worthless.


FI is more responsive and easier to tune, but the same can happen if an injector sticks open or a channel shorts. its harder to troubleshoot FI systems when they dont ack rite. lol.. OBD makes life worth living tho if you know what to look for.


 

·
Powerhungry
Joined
·
38,189 Posts
99% of bikes do not have accellerator pumps. unless you have something with FCR39s or 41s or similar badass carb rack.

the vacuum piston is what regulates airflow so the motor doesn't spin up too fast for the fuel to get pulled out of the emulsion tube. also why i drilled my slides out to make them pick up faster. thats why it works the way it does.
yes. so, like i was saying.....
 

·
Registered
Joined
·
3,741 Posts
All I know is if I pump the throttle on my suzuki I can flood it.. plus every Harley Ive ever ridden is the same way. Maybee I've just happened to ride bikes like that.
 

·
Registered
Joined
·
28,313 Posts
well. *real* bikes. not suzukis or harleys.

:lol:


ya HD runs pumps on their shit since they have a HUGE fuckin twin sucking thru a small single carb and will never change that. it worked back in the 20s.. why deviate?

thing is the pump tosses very small amounts of fuel out, but it's not atomized fuel. as far your suzuki weeble, not sure what you have. about 99% of off-road shit HAS a pump. smaller bore stuff like xr100s and whatnot don't. the carb on my kx125 is HUGE but it doesn't have a pump. nor does my XR, Z50, or FL250 odyssey. stuff usually over 300CCs will tho. theres a 400EX at the shop and i think it has a pump..

ramble yayyyy
 

·
Registered
Joined
·
3,741 Posts
The suzuki is a 1980 GS550L thats had a hacksaw taken to and looks pretty baddass to be honest... Im not 100% on if it has a pump or not but I have flooded it before when I was learning to start the thing by pumping the throttle.

I just assumed all bikes did that since every carburated one I've rode will.
 

·
Registered
Joined
·
28,313 Posts
The suzuki is a 1980 GS550L thats had a hacksaw taken to and looks pretty baddass to be honest... Im not 100% on if it has a pump or not but I have flooded it before when I was learning to start the thing by pumping the throttle.

I just assumed all bikes did that since every carburated one I've rode will.
that would be a sticking float, sir. that, or simply too much air and fuel going into a small motor.

lol the GS550 is a CV carb bike IIRC.. been a few years since i worked on one.
the fuel petcock is vacuum operated and oft times the diaphragm fails in between the vacuum chamber and the fuel chamber and the #1 cylinder floods from pulling fuel from both the carb and raw fuel thru the vac line thru the bad diaphragm.
it happens alot on the GS bikes. the 4 cylinder bikes always wipe out cylinder #2 since thats where they source vac for the petcock. if you ever see one that only runs on 3 cylinders and #2 won't fire, thats probably whats wrong.

most bikes tho don't have pumps. HDs do, anything with FCR flatslides like the old ZX7RRs and some of the older R model 7s from the early 90s.. theres probably a couple others i don't know off the top of my head. these stupid fucking scooters i seem to work on alot.. ALL those goddamn things have pumps. boggles my mind. lol cute little carbs with pumps on em. wanna put one on the Z50. should do well with my ported head.
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #11 ·
Okay so it is just a matter of whether or not there are accelerator pumps?

For cars carburetors almost always implies accelerator pumps.
For bikes: HD's, off-road's, scooters, some old carbed sportbikes.
For both, FI means its fine.
 

·
Powerhungry
Joined
·
38,189 Posts
Okay so it is just a matter of whether or not there are accelerator pumps?

For cars carburetors almost always implies accelerator pumps.
For bikes: HD's, off-road's, scooters, some old carbed sportbikes.
For both, FI means its fine.
yes, for the most part thats correct.
 

·
Registered
Joined
·
3,741 Posts
In regards to the petcock on my old suzuki.. I know exactly what your talking about. The stock vacuum operated one was gutted and an inline petcock was installed in the fuel line several years ago. The diaphram went out like you where talking about and caused a crap load of problems.
 

·
Registered
Joined
·
28,313 Posts
In regards to the petcock on my old suzuki.. I know exactly what your talking about. The stock vacuum operated one was gutted and an inline petcock was installed in the fuel line several years ago. The diaphram went out like you where talking about and caused a crap load of problems.
;)

*brushes shoulda*
 

·
Registered
Joined
·
28,313 Posts

·
Registered
Joined
·
28,313 Posts
I twist the throttle with the bike off all the time. My accelerator pump is working fine.
yours is an inverted model designed for that. only came on your year
 
1 - 20 of 27 Posts
Top