MC-54-250B Vacuum Lines By redscoot (Read 6,149 times)

[redscoot]

Hello board, newbie here. I am looking for a picture or illustration of the vacuum line connections to the carb and fuel pump. I recently purchased a Roteka MC-54-250B which I believe to be a 2007 model. The guy I bought it from told me he installed a new improved fuel pump on it. The scooter starts and will run for a bit, then it dies as if it has run out of gas. I replaced the fuel filter, changed the oil, and cleaned the air filter. With the scooter on it's stand, if I run it at high RPM for a while, the fuel in the filter seems to drain right before it quits. There is a black cylindrical canister mounted on the frame with some hoses coming off it that are not attached anywhere. I think when the previous owner put the new fuel pump on, he messed up hooking the vacuum lines back up. Any help getting them straightened out would be appreciated.

[alleyoop]

That canister could be one of 3 things:
But I think it is a EVAP system which I believe is the most likely:
it is a VENT for the gas tank to trap the fumes and send them back into the intake to be re burned.

Now that canister requires VACUUM so make sure the Vacuum line coming from the INTAKE MANIFOLD is plugged up otherwise your loosing vacuum to pull full from the PETCOCK or FUEL PUMP.
If you could take a picture of the CARB AREA and hoses and the CANISTER that would help with telling you if the hoses are correct and connected correctly.
Alleyoop

WHICH MOTOR is on there the VERTICAL HELIX 244cc or the LINHAI HORIZONTAL ?

EVAP SYSTEM:

[JR]

Got pictures of the lines, just got to find them?

[JR]

Found them!

[redscoot]

I have the horizontal engine. Here are some pics of my current configuration. What are the 3 ports on the fuel pump? there are no markings to determine how it is to be connected? Also, there are at least 2 capped off fittings on the carb, is that correct?

Thanks for the help!

[scot]

not that I know much but do i see  2 or  3 hoses not attached in the 3rd picture try pluging those hoses in .looks like wear they go  did you unhook those for some reason looks like thats wear they would go,the other guys will know if that's the fuel pump,not being able to get the gas to the carb ,I am only guessing as I try to learn ,hope you get it fixed soon scott

[alleyoop]

That is your fuel pump notice the ARROWS on the top pointing in and out. the center one is your vacuum diaphragm hose.
Alleyoop

The previous picture was wrong, The pump like JR SAID has TWO OUT connectors and one should be plugged OR go into a "Y" and then go to the FUEL FILTER then to CARB. Here I relabeled the pumps ins and out connectors correctly. Just look at the ARROWS on top it tells you which is IN FUEL and OUT FUEL connectors.



THIS IS YOUR CARB: NOTICE the not used ports: They used to run lines from the radiator to it and return back thinking it would warm up the area for the fuel going to the ENRICHER for cold starts.

[JR]

Alley is right on but I'm seeing some things that need attention. On the picture of your fuel pump which BTW is a dual outlet mikuni pump one of the hose clamps has been bent and is basically useless as far as putting any clamp pressure to hold the hose tightly. They used the cheapo Chinese hose clamp on the vacuum line, a no no, replace all these clamps with good quality hose clamps from the auto part along with the ones on the carb or use good wire ties and snug these hoses tightly.

Second as I mentioned this is a dual outlet port pump, the choices are block one port off or use a "Y" connector and put both outlets together to make one and then take it to the carb fuel inlet. Now Alley has marked all these lines on the pump correctly so you'll need to trace them out and the hose on the vacuum for the Y in the second picture doesn't even have a clamp at all, if it is losing vacuum in any way no fuel will be pumped. Secure all lines with clamps or wire ties correctly.

The side hose connections that are capped are not needed as Alley mentioned. It appears the former user replaced some lines but not all of them, I recommend getting new vacuum hose of the correct size and replacing them all and clamping them securely.

JR

[alleyoop]

I corrected the Pump Picture it was wrong.
Alleyoop

[redscoot]

Thank you all for the wonderful amount of information you have provided. I now have plenty of stuff to try tomorrow. I will post my results afterwards.

[ellpee]

Alleyoop, when you finally pass on to your eternal reward at age 137, I sure hope you'll leave your photo collection to the Smithsonian or something. It's a national treasure!

[alleyoop]

I will give the pictures to JR. OH WAIT!! he will also be feeding the worms
Alleyoop

[scot]

great pictures guys ,they are so very helpful ,,