Four wheeler question

I never looked close at a four-wheeler ATVs until this winter. I bought six of them and have been going through them, one by one, in my
shop this winter. Near every Japanese make. Yamaha, Kawasaki, Honda, and Suzuki.

I have a 1992 Suzuki 4WD 300 King Quad I am tearing apart now. It as an ice-fishing lake rig. No woods or field riding. Kind of like
having "highway miles." Owner gave up trying to keep it running. Kept running out of fuel.

Questions? This ATV has a gas tank a lot higher then the carb. Yet it is a vacuum-operated fuel pump. Suzuki says it is not repairable a
new one is $100.

#1. Why cannot I just hook up the fuel tank to the carb with no fuel pump with gravity feed? All I can figure is maybe if going down a
very steep hill gas might not flow well? Old Ford Model Ts had that problem.

#2. I am wondering how a person is supposed to prime this system when it runs out of gas? I do not have a 1992 owner's manual that might
have that answer.

I also have a 1995 4WD Suzuki King Quad I just finished and that has a fuel-primer-override to get it started if it was run out of gas.
This 1992 has no primer or override.

I think my Yamaha is gravity feed. It has a reserve , off & on switch (valve)

You could probably eliminate the fuel pump, as long as there's not a strainer that's too restrictive. My wife's Suzuki motorcycle has a pretty fine strainer in the bottom of the tank, and it's gravity feed. You could also just add an inline electric fuel pump.

I just thought of something else, it's not fuel injected is it? My Triumph motorcycle is, and it has the fuel pump and filter inside the tank. When you turn the key on you hear it buzzing and then once it builds up pressure it shuts off. We each have Honda 4-wheelers that are gravity feed, and work fine.

Put a boat primer squeeze bulb between tank and carb.
$6

Is it vacuum operated or crankcase pulse?

Is it possibly a fuel shut off instead of a pump? Or combo?

Could probably be replaced with B&S fuel pump and a shut off valve.

Wouldn't think a primer would be necessary, might even work as a total gravity feed with no pump.

Some bikes have a vacuum operated petcock. How much fuel pressure could the little pump supply?

get the number off the pump and check ebay, you may get a pleasant surprise.

As to priming, a vacuum pump works at cranking speed. All it takes is a few rounds of the engine to pump fuel into the carb.

(quoted from post at 09:03:06 02/07/18) Is it vacuum operated or crankcase pulse?

Is it possibly a fuel shut off instead of a pump? Or combo?

Could probably be replaced with B&S fuel pump and a shut off valve.

Wouldn't think a primer would be necessary, might even work as a total gravity feed with no pump.

Click to expand...

I put a B&S pump on my POS.The original caused the engine to break up at high revs.Seems to me since the tank is well above the carb.,gravity feed would work.

This would probably work.

https://www.ebay.com/itm/New-Electric-Fuel-Pump-For-Motorcycle-Low-Pressure-12V-Carburetor-FP-02-ATV/272357036741?epid=1272675779&hash=item3f69be92c5:g:cXgAAOSwe-FU8HHs&vxp=mtr

I'd guess it's a gravity fed system, not a fuel pump. Suzuki used some shutoff valves that required vacuum to open the valve

If the previous owner couldn't keep gas in the carb, and the fuel pump is no good, it stands to reason that it will not run gravity feed, otherwise it would have run fine even if the pump were bad.

My Kawasaki Vulcan had a vacuum operated fuel shut off valve at the petcock. That took some ingenuity to get gas to the carb without the engine running. I tore that sucker apart an took the useless guts out of it and now use the usual lever to shut the fuel off and on. TDF

In answer to a few questions and/or comments . .

"get the number off the pump and check ebay, you may get a pleasant surprise"

Been there, done that. In this case, no bargains.

"Is it vacuum operated or crankcase pulse?"

In my world, vacuum and pulse are the same thing. An engine with a piston that goes up and down make pulses. A vacuum-operated fuel-pump has check-valves to created a vacuum.


"Is it possibly a fuel shut off instead of a pump? Or combo?"

My 1995 Suzuki has a combo. Vacuum-controlled shut-off valve under the tank and a separate vacuum-fuel-pump. It also has a "primer" position on the fuel shut-off valve under the tank to make starting easier if it has been run out of gas.

The 1992 Suzuki that I have tore apart has a conventional tank shut-off valve. Just "ON", "OFF, and "RESERVE." That is connected to a large vacuum-fuel-pump that works off the engine crankcase pulses. I say "large" because it is twice the size of a Briggs&Stratton pump.
The OEM Suzuki pump is riveted together. I have not tested it yet. Just wondering why I need it at all. I am wondering if Suzuki only put it there to prevent carb flooding when the engine was off and did not want to trust users to remember to turn off the gas-valve.

The Briggs & Stratton pump is only $12. Beats near $100 for the Suzuki pump. I might buy one just to have on hand, IF I don't wind up using it.

Funny this came up. I have a 2000 watt Generac Inverter generator that does not want to start. It has a conventional choke plus a push-bulb gas primer. No matter how many times I push the bulb, it gets no gas. I just tore it apart and to my surprise? The bulb does not pump gasoline like I thought it did. It sends a vacuum signal to a vacuum-fuel-pump. Not working, but all this time I thought it was a direct gasoline primer.

Isthere am inline filter in there that could be plugged up?

THE EASY WAY IS TO JUST PUT AN ELECTRIC FUEL PUMP ON IT, THERE SMALL, DONT TAKE MUCH CURRENT, PUT OUT ABOUT 2PSI. THEN YOU WORRIES ARE OVER BUT I WOULD PUT A CLEAR INLINE FILTER IN IT SO YOU CAN SEE THE FUEL IN THE FILTER JUST BEFORE IT GETS TO THE PUMP SO YOU CAN SEE IT HAS SUFFIENT FUEL.

In your case its cheap enoufh to give the Briggs a try... The Briggs looks like the one on my EZ go golf cart that's crank case pulse...
It was also dirt cheap...

I don't remember zackly what I went thu I ended up removing the carb and cleaning the needle/seat I think those pumps want pump if the outlet is not open.... When the needle in the carb blocks the fuel they won't pump nor suck fuel...

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Whizkid
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