Razz not starting

[QurazyQuisp]

Hello all,
I have an older Yamaha Razz and it doesn't seem to want to run. The moped will start up with some starting fluid, but run until the starting fluid is gone and abruptly stop.

It seems like it has something to do with it not getting gas, however we've cleaned the fuel filter and made sure that the fuel lines were not clogged.

I'm not quite sure where to go from here.

[QurazyQuisp]

So I see from other threads that it is probably a fuel supply issue. I can move air through the vacuum tube to the gas filter/pump, but once I get there, if I try to suck no much really happens, and if I blow you can kind of hear a pumping action.

Does anyone know where to go from here?

[fastrazz89]

First, make sure that the fuel vacuum pump is functioning properly- you may have to take it apart and clean it up.
Next, clean out your carb and all of its little passages really well- you will probably need some good carb cleaner solution and an air compressor if it is really dirty and gummed up in there.
Try those first. o_o

[QurazyQuisp]

What does the fuel vacuum pump look like? is it where the tube goes into the carb? or is it the "fuel cock"

[fastrazz89]

The vacuum pump looks like a fuel cock.

[QurazyQuisp]

Hmm, I decided to just go out and buy a new fuel cock, I took apart the old one and the diaphragm seemed to be wrecked. I installed the new one and we're still at the same spot. No gas is getting past the fuel cock.

[fastrazz89]

It IS working correctly- if you have it hooked up to the scooter with the fuel line from the gas tank connected to the fuel cock and have the small vacuum line connected to the carb- if you leave the fuel line that normally goes to the carb disconnected and crank the motor over, fuel should shoot out the disconnected line. The vacuum fuel pump is designed to only pump fuel when the engine is running (forcing vacuum through the vacuum line to the pump) and when the engine is not running (no vacuum) no fuel is pumped.

[QurazyQuisp]

Ok, so the fuel cock is working correctly, I took the rubber tube off the carburetor and kicked it a few times, it spat some gas out every time.

So, it must be something in the carburetor... any guesses as to what?

What should I be checking for? What's the proper way to clean the carb?

Also, I took the gas line that goes to the carburetor and blew into it, and it seemed to be completely clogged up. Should it be this way? or should it flow into the carburetor?

[fastrazz89]

Yes, the gas line that goes into the carb should flow freely- take the tube off and remove the obstruction if possible, otherwise replace the tube.

For your carb, get a phillips screwdriver and a flatblade screwdriver. Remove the carb from the scooter- it is held onto the engine by a hoseclamp; loosen the hoseclamp and the carb should come loose with a little bit of wiggling. Then, take the phillips screwdriver and remove the screw from the top of the carburetor. Now you should be able to take the top of the carb with all of the cables and needles off of the carburetor. Now take the carburetor somewhere that is brightly lit and clean. Disassemble the carburetor- take the phillips screwdriver and remove the float bowl from the bottom of the carburetor (there may be some gas still in the float bowl). Take the phillips screwdriver and remove the float (the round thing that bounces up and down in the bottom of the carb). Be careful to not bend or lose the little needle that is attached to the float. With your flatblade screwdriver, remove the two brass jets in the bottom of the carb.
That is it for disassembly. You may want to take some carb cleaner and an air compressor to blow out ALL of the small passages in the carb and its jets. By all means get ALL of the small passages clean- even the smallest bit of gunk will throw off how the scooter runs. Also be sure to clean the little float needle well so it doesn't stick.
Once you have everything all clean, re-assemble the carb- put in the brass jets, put in the float AND NEEDLE in (make sure the needle is hooked to the tab on the float) and screw the float down into its proper place. Be sure to connect all lines to the carb, especially the tiny oil line. Finish re-assembly and put it back in the scooter. Once the scooter is fully assembled, make sure you have FRESH gas in the gas tank and have a new spark plug in the scooter.
Sorry for writing a how-to novel, but I really hope this works out for ya! ;wink)

[QurazyQuisp]

The clog seems to be in the carb where the fuel line connects, not the tube. So, what I'm wondering, should the fuel flow freely into the carb?

[OldGuy1]

The clog seems to be in the carb where the fuel line connects, not the tube. So, what I'm wondering, should the fuel flow freely into the carb?

If the float bowl has fuel in it, than no. That's what the float and it's needle and seat do. They control the amount of fuel in the bowl. Hence the reason for setting the float height.

If the float bowl is empty and fuel isn't flowing you may have a stuck or leaking float.

[fastrazz89]

The clog seems to be in the carb where the fuel line connects, not the tube. So, what I'm wondering, should the fuel flow freely into the carb?
It should flow freely but to a point- thats what the float is for... take the carb apart and clean it well.

[QurazyQuisp]

Fastrazz89, thank you very much.

I cleaned the carb and put it back together and it started right up. It seems to run pretty decently now as well. Unfortunately the throttle cable broke when I was running it, but the old owner bought a new one so I'll just replace it.

Again, thanks very much.

[fastrazz89]

Hey no problem man! If you have any more questions, please come back ;wink)

[QurazyQuisp]

I do have one final question, if you'd like to answer it...

What is the best way to put the airbox back on? that thing is pretty stubborn.

[fastrazz89]

LOL I've run into the same problem... you CAN get it on if you sit and wiggle it on for 10 minutes, but the way I've found best is to take all of the bodywork off and it is easier to put on like that. It is a really sucky to put on, not much we can do about it lol.

[Jimb1947]

fuel should flow into the carb unless the fuel bowl in the carb(under the fuel line connection) is full or the float valve is sticking. You should be able to blow into the carb if the float bowl is empty.