MC 54-250 Vacuum line goes where?

[firestrom]

Hello

I got my title today and my license. Took the 54-250B to work ran great. This evening I took it out for a longer cruse and she started to hesitate at about all speeds and gradually got worse but never died. I looked it over and found a vacuum line off now it comes from the left side under the motor and up to the right. I looked all over for where this vacuum line plugs in. I searched for pictures or anything that would help on this great site but no luck. I have the MC54 250 b with the 244cc motor can some one please help me.

Thanks Jesse

[fufu2wheel]

Donno if this helps:

Fuel pump:

[yarddogbbq]

does it go to muffler?? or back up toward gas tank?? or carb??

by the way you changed oil, gear oil, brake fluid, coolant right?? fuel filter for small engines simular in size. backed your mixture out 1/4 turn?? before riding??

learn how to adjust the valves, do a thead search for this. after afew miles adjust valves the engine and fuel valve/pump needs good vacuum to operate at maximum effeciency.

loosen your gas cap retighten it, and see if that helps.

look at the black plastic canister near radiator it should have 3 hoses hooked up to it. one is vacuum hookd to top of canister then to carb plug this line. or eliminate. get rid of one "T" connector. the canister is cheap and they malfunction early from dust thrown up by front wheel. so before it does.

the intake manifold originates the vacuum hook ups on left (sitting on seat) side of manifold. make sure you got one to the fuel pump/valve (depends on what you have) near gas filter. and one to back of carb to coast enricher. (little round sorta looking part behind the brass diaphram cap.)

as in this picture:



see the vacuum hose going to the intake manifold and to the carb coast enricher?? small black tube.? the main vacuum hookup is to the right near and before the brass cap. it hooks to vacuum port connection then branches to the coast enricher on the left and to the fuel valve/pump. (only two you need)
there is a vacuum line that goes to the charcoal canister near radiator and up to left vacuum hookups. unhook this one and simplify the vacuum lines so you have only one "y" or " T" connector. (simple is better)

so in review hook vacuum line to intake manifold (sometimes callled carb insulator) go to coast enricher, then to vacuum valve (or pump like you have)

the only thing that you need hooked up to this is the fuel valve/pump. if you have the 244cc cfmoto engine. yo do have the cfmoto 244cc engine right???


yarddog

[alf]

i could be wrong, but i understood that the mc54-b model all had the 257cc engine and the non b had the 244cc engine ,is this correct?

[yarddogbbq]

the loose hose near the fuel pump in the pictures above my post above is probably the carb drain it does not hook up to anything. there is a screw on the front or carb that you loosen to drain carb, in case of water in fuel, storage for winter etc.

good pictures. of cfmoto 244cc engine.

yarddog

[fufu2wheel]

Jul 29, 2008 7:35:49 GMT -5 alf said:

i could be wrong, but i understood that the mc54-b model all had the 257cc engine and the non b had the 244cc engine ,is this correct?

There has been some threads about MC-54-250B with 244cc engine config. Chinese manufactuer inconsistancy make scooter purchase even more of a crap shoot... enty up and roll... you never know what you might get.

[firestrom]

Thanks for the pictures and replies I am at work so can¡¦t really give it a good look but the vacuum line comes from the left side under the motor it looks like it is coming from the air filter area. All vacuum lines are in place on the carb and fuel pump it looked like it was going towards the radiator area but can reach carb.
Yarddog I did a PDI on it. Changed all fluids replaced fuel lines Filter and clamps. I checked all the vacuum lines and all was attached to something at the time, at the time of PDI I thought ļ. This line must not be too important as the bike ran fine for me to work. I will look again after work.
The scooter started up and ran fine this morning to work About 2 miles and a cool morning. I drilled small hole in the gas tank lid. Will see if that helps.
What I will do is try and take a picture of it tonight after work and see if that helps.

Thanks you fufut2wheels, Yarddog for the help

thanks Jesse

[earlwb]

well you have a vacuum line that goes to the carb. Another vacuum line goes to the fuel pump. Then another vacuum line goes to the vacuum controlled valve for the PAIR system.
There are some instances where there is a vacuum line going to the vacuum valve on a fuel tank carbon canister as well.
it is common for the air intake hose on the PAIR system to be left open and dangling someplace.

The crankcase vent line goes to the air filter box. Another hose from the carbon canister goes to the air filter as well. On the other side of the carobn canister is the fuel tank vent hose and it also runs through a one way valve on its way to the fuel tank.

There may be a overflow tube coming off the carb and or a float bowl drain hose too.

[firestrom]

alf
What I have is a 2008 54-250B with the 244cc motor so it is a 250 non-B but I have the 250B's sound system and box. so it looks like a 250B but with the 244cc motor. I hope that makes since:- ) I am not sure about the length whether I got the extra inches or not.

thanks earlwb I hope I don't have to tare it apart just to finger out this one vacuum hose.

Jesse

[earlwb]

To make it more interesting, I had found a length of extra vacuum line in my scooter, open on both ends, going nowhere. I spent a long time looking to see if it was being used anywhere. never did, and since the scooter was working OK, I eventually gave up on it, and pulled it out and stuck it in the tool bag in case I needed a piece for something.

[firestrom]

Up date

I took the scooter out for a ride and it ran good. I did notice a small hiccup at 35 if I speed up it would go away and if I slowed down to 25 it seems to go away the top speed I ran it was 50 to night for about a mile or so and no problems. I still can’t figure out that vacuum line though LOL.

Will switching to a different fuel pump solve this little hiccup at 35? I am thinking of taking it for a 16 mile run but don’t know if I should tell I solve this hiccup. I hate to get stranded, I hate walking LOL. Any who thanks all of you for your great help and this forum as it is invaluable.

Thanks Jesse

[yarddogbbq]

firestrom,

if you suspect fuel pump try a briggs and stratton vacuum fuel pump i hear they are pretty good.
make sure b &s is a pump not a vacuum valve like gravity fed bikes have.

electric pump, say a facet with a 1-3 lb setting would probably work great.

the bike will run better with more miles put on it.

you can check the small white filter (if your carb has it) in the pic below it just pulls out of fuel inlet. clean in carb spray and put back in.
you can take fuel pump off and submerge in marvel mystery oil, or kerosene or diesel and operate the vacuum line by a hand held vacuum pump or mouth and make pump work a few times and reinstall.
shake most of kerosene out of course. pump might be sticking for some reason.

but check the fuel inlet strainer below and clean:



hope this helps

yarddog

[firestrom]

Long ride

WOW WHAT A RIDE!!! I took the scooter for a long ride this morning 50 miles it ran like a champ took and fixed Tom Tom to scooter it is 10 mph off on speedometer. I can live with that. I had forgot how much fun two wheels are. The hiccup went away so very happy.

Thanks Jesse