4 Stroke Question

Thats a pulsejet carb. They have a diaphram that pulls the fuel up. Very simple straight forward carb. Norman can tell you how to make em run on Alky........................

Check the diagphram, check the pickup tube and make sure it's not covered with crap or stopped up. You can blow through the gas cap vent and push gas into the carb..................

Brigs shows this in their repair book, they say if your engine has been stalling intermittently,remove the gas cap and try to start the engine.If it starts replace or clean vents in cap.HD

Get a re-build kit and thoroughly clean the carb.

My Briggs boat motor has a different fuel pump, but though it looked fine, I had to re-build it... twice in two years.

replace the diaphram its about $2.00 comes with the spring and spring cover disc. take out the main jet if it is the old type and clean out main jet check to make sure the needle is not damaged and the jet hole isn't damaged or plugged. There is 2 small holes behind the main jet blow them out with compressed air do not run a wire into them. take the carb off the tank and make sure the ful pick up tubes are clear there should be small screens on them. clean out the tank and the small resivor that the short pick up tube goes into. make sure that it does not have a hole in it. chack your valves on the engine too a sticking or stuck valve will keep it from running.
Now for the alcohol thing send me your carb and I'll modify it for the fuel it will then be a gas hog and with other mods. depending on how fast you want to go I can mke the engine put out about 18hp and turn up to 9000 rpms. It won't be cheap. over $800.00 for an outlaw engine.
you picture of the fuel pump is correct if I could see the other side I could tell if its a newer carb that you can't adjust the fuel mix on looks to be the older type.
Norman

2door:

It sounds like you've covered all bases!

I'm no expert...a few go-carts...mowers.

The engine may be just worn out...like the guys were saying the pump works on a vacuum pulse during the intake cycle.

I think I would do a compression test, and then a cylinder leak down.

Just guessing here...Norm what do you think?

If the engine is worn out, needing a valve job...rings, would that make the vacuum pulse weak enough so that the fuel pump woundn't work?

Maybe pull the head and see if there's a lot of carbon on the backside of the valves?

Jim

I think there is a clog in the carbs fuel system or the small fuel bowl in the fuel tank is holed out changing out the fuel tank to a known good one will solve the problem if the small fuel bowl inthe tank is holed out. he's got to get a new carb diaphragm as if it stiff or a micro hole it won't run
the fuel passages behind the main jet can be clogged and that thing will never run if they are.
If I could get my hands on it I know I can make it run and run right or at least tell him if it time for the engine to take a dirt nap.
I've seen all kinds of problems with these engines some you would not believe and had me stumped worse one was my alcohol engine would run like a scaulded dog then would loose power like the fuel was shut off took a while to figure that one out turned out to be a loose intake seat it would come loose and move with the intake valve shutting off the intake. taking a center punch and peening in the seat then reginding/lappng the intake valve and adjusting the valve lash solved that problem for good.
if you really want it to run mail it to me and I'll fix it charge you only for shipping and what parts it needs PM me and let me know. you could just send the carb and fuel tank as i think the problem is in the carb/tank

I think I an an expert on these engines. big grin

this carb works off of the pulses from the intake it pulls fuel out of the tank into the pump then into the small tank/reservoir inside of the big tank that the short pick up tube uses to pull fuel into the main jet rough setting for the main jet is about 3to 4 turns out fuel enters the main jet goes through a hole in front of the brass main jet through the main jet into the slot that has 2 holes in it one is for idle and the other is for above idle somewhere you have to be plugged off on one of those passages.
something else if one of the brass pick up tubes has a pin hole or crack or is loose it will not run. when one of these engines is running you can take off the gas cap and with a flashlight look inside of the tank and see fuel dribbling out of the small reservoir and back down into the main tank.
These carbs also have a spiral vane inside of the carb body to help with the atomizing of the fuel really not needed in some uses as in go karts engines I pull them out and toss them.
I think it shouldn't be over $4.00 to ship it to me for repair but in these tough times and through the use of this forum we should be able to get you going. Look close at the gasket between the carb and the tank if you have it on wrong or if it for the wrong model you might have a port that might be covered up I have some gaskets that I could check on if you can post a picture of yours and I'll check it against one of mine that thing will run something is plugged off these carbs are dirt simple once you know how they work.
Norman