250cc Roketa MC-54B-250 Problems.. By Chris Waddle (Read 28,654 times)

[pop1205]

Okay that cleared up some confusion. I was looking at the GY6 valve adjustments and was blown away when I tried to do mine. lol
After cleaning a carb.. Do you have to manually put gas into it? I believe my carb is getting no gas at all and my scoot will not start at all I think trying and trying may have led me to have a weak battery now or even a going bad starter. Maybe a bad spark plug. By the way, where is the spark plug on this thing? I would like to examine it and potentially get a new one. I am willing to give this scoot another shot. Just might need some help. Trying to keep the good spirit going! ;D

[yoster]

Hey man,

Hang in there! I know your list sounds like a lot but honestly these are all things that can be knocked out in just a few hours.

1. Won't start now, has that weak sounding start. - Charge your Battery

2. Need a new enricher. - Check the connection first. One of the yellow wires from the stator will have a 4th yellow wire coming out of the connector they go to. Be sure that's connected well to the enricher. If it is, and the problem is the enricher, it's a 5 minute fix. Hopefully it's just a bad connection though. A bad connection there will cause the enricher to not function properly, resulting in the high-idle you're experiencing.

3. Need to adjust valves (tried to today and have no idea where the heck anything is) - this is VERY easy! (Do you have the cfmoto version of the engine?). Read the "poll" at the top of this thread and look at the video I posted. I promise you, this takes no time at all and is something you shouldn't stress out about. I too was intimidated by it at first, bu after actually doing it, it's now a no brainer.

4. Need to check spark plug (absolutely no clue to the where abouts of this) - Again assuming you have the cfmoto engine. If so, it's on the side opposite of the muffler. Ger under the scooter and look up towards the seat. You'll see the spark plug wire going to it; it's coming out the side of the engine at about a 45 degree angle. You can also kind of see it when you open the seat and open the little access hatches. It's on the side of the valve adjusters, just below them.


5. Need to fix my squeaking problem. - Lets worry about this one later

6. Need a new back tire. Won't hold a complete fill. Only holds about 65% of air. For the time being, you might want to throw some of that green slime in there. Don't do this until the scooter is up and running and you can ride it around a bit. This could also be (and probably is) your valve stems. Before slime, start by replacing those. I haven't done it but I understand it's quick and easy.

7. Need a new right side mirror. - lets worry about this once the scooter is running.

8. Need a new bulb for right tail light. - 1 minute fix; bulb can be found at wal-mart. #1157 - Do not replace until item below addressed.

9. Still having electrical problems. Yellow wires coming from regulator are getting very hot and are melting. Oh joy. - Your RR is faulty and not limiting the volts to 14.5. One of my many RR's I went through did the same exact thing. Resulted in several blown bulbs too (a few of which were LED's, arg!). Once your other items are addressed, a simple RR from Oregon Motorcycle Parts (you can PM Damin or I about this), will fix this issue; we'll do some testing first though. Again assuming this is the cfmoto engine.

10. Need to see what's with my breaks. They don't seem to be "all the way there." - Explain?

11. Need a new air filter. - Lets order one!

[pop1205]

Thanks guys!! Going to head out there today and show this scoot who's boss!! lol
Going to get my battery charging while I do my other things.

Last question: After completely taking off a carburetor (and all the gas in it draining) how do I get gas in there again? Seems to me that it's getting no gas at all. When I take the gas hose off of it no gas spills out, rather than when I took off that hose firstly all the gas spilled out. As you can tell I'm still new to this guys Bare with me, I am willing to work these problems out!

[pop1205]

So. Changed my gear oil successfully. Piece of cake. Thanks for the help.
Now. About the valve adjustment. I had the valves exposed and was going to take the cover off of the timing belt so I can get the engine in Top Head position (or what ever it's called, name isn't coming to me right now). Well, the one of the two screws for it came of easily. The other is the one giving me hell. It is an inch from the frame. I can't get my ratchet in there. A 8mm wrench fits fine. But keeps slipping !!!! I went to the auto place and got a "ratchet wrench". Pretty cool thing. Didn't work. Kept slipping. It appears that that screw was already stripped. I CAN NOT get it off.
Also, I do not have a screw driver big enough to take the black CVT cover off. It's dreadfully tight and my nubby is not suitable for that. Soooo everything is going bad. So after getting frustrated with this dang scooter, I put the valve covers back on and everything how it was supposed to be. I had my battery charging while I was at work. Put it on, and tried to start. Very weak again. I believe it may be my spark plug. Hopefully not the starter.
This scooter is getting to become a burden rather than enjoyment. 75% of the time I spend with it is just to get it up to par. The other 25% I'm on it wondering why it's running the way it is.
Only thing stopping me from doing the valve adjustment is that one dang stripped and VERY tight and hard spot to get to bolt. Now I have to use Public Transportation :/ I'm trying to hang in there. It's I get one thing fixed and then it's suddenly another thing...
So any suggestions on getting that bolt of of the timing chain will be greatly appreciated as always.

[ce]

Dude, you can do the valve adjustment by feel. If the intake valve has any play in it, assume it to be closed. Tic the starter and hang on to the rocker arm with your fingers through a couple revolutions.

If it never loosens up, you have no gap. Tic the starter til the arm is in an upward position and set the gap to .004

Now tic the starter until you have your gap again and check the exhaust valve, it should have a gap as well. Set it to .006 if you can get to it, or just rock it up and down with your fingers til you feel a little gap.

You are now close enough and it should fire right up. I just did this Saturday, ran it hard and found the intake had opened up a bit too much because it was clattering, reset it and it runs better than ever.

I'm not saying this is any correct way to do this, but it is close enough, and I'm riding. All you need to do is leave room for the metal to expand when it heats up.

[yoster]

pop - I think one thing that's making this harder than it needs to be is that you're pretty new to engines and how they operate. I.e.: A spark plug has nothing to do with how quickly an engine cranks. I would treat this as a good opportunity to learn some "engine mechanics 101." Though I can understand that you're probably looking forward to riding!

Note - it sounds like your battery is just weak. Did you give it a full charge? What kind of charger are you using? If it's a 1-1.5 amp charger it's going to need a good overnight charge (provided that the battery isn't junk).

Also - It's called "Top Dead Center, or TDC"

[pop1205]

I would like to adjust my valves that way. I don't know what you mean by tic the starter and the swingarm... I'm awfully new to this and trying to save money. I'm learning A LOT this way!!

Here's an UPDATE: Good newsssssss!!!!!!! ;D ;D ;D
I've got my scoot to start
Turnssss out the dumby (me) who took the carb apart and put it together didn't put it together properly first. Didn't put the enricher on right nor the throttle cable. So when trying to start my scooter I was getting no gas at all and thus drained my battery. Left my battery while I went to work. Tried it again and had the same drained battery. My charger never worked. So got out a different charger that did and let it charge over night. Came back to it today and tried it, and it was doing the same thing. I adjusted my enricher in all the way and found how the throttle cable properly went on. Put it on, and my scoot would almost start. On the vurge but wouldn't completely come on. Turns out that my idle screw was set way to low. With the throttle cable in the wrong spot (the entire time before I messed with the carb) my screw never went all the way down and my throttle was always slightly engaged. So I had to adjust the idle screw so my scoot would actually start and stay on. So it took a few tries but I actually got my scoot to run and stay running again!! Only thing is that it's just like before so I must adjust my valves still but I at least have it up and running again. Now with new gear oil ;D

Only problem though: When my fan clicks on, my rpm shoots down and will sometimes turn my engine completely off. This was happening before I took my carb apart as well. Except that the rpm would drop fast when the fan kicked on and idle at a mesly 1,000. So, now it will just shut off, but a quick boost of throttle rams the rpm back and it idles fine after that, until the fan kicks on again. Any idea what this could be guys?
Maybe the valves?
My idiocracy of engines is quite apparent. LOL

[Alleyoop]

You may have the IDLE SPEED Screw set to low. The Engine should Idle at 1500-1800 rpms.
If its below that anything that takes juice from the Coil will cause it to Idle to low and kill your engine. So set your Idle up with the Idle Speed Screw turn it Clockwise just a little.
Alleyoop

[pop1205]

Alleyoop,
Thanks for the suggestion. Already did that. Only problem is that I believe that my enricher is messed up. No matter what I set my idle at it will always idle at about 2000 and spin my tire like crazy. So I'm going to order a new one tonight.
Every since I've cleaned my carb and took the cap off of the valves, and finally getting it to start, my scoot has been running like UTTER CRAP. Constantly bogging down. When it turns on (after about 7 cranks) it will idle super high, then go down and shut off. I must give it gas to try to keep it up. Sometimes it will just drop too fast and no matter how much gas I give it, it will shut off. When it's actually on and warm, driving it is just awful. It will not stop bogging down. It will do 50 but still be bogging instead of going smoothly. Could have taking the cap off of the valves caused it to run worse without adjusting them? I do have the caps back on. Didn't adjust them because I couldn't take the timing belt. But one user suggested that I do it by feel and tik the starter while leaving my fingers on the swing arm. Seems like the only way I can even get close to doing my valves. Oh, and I discovered what ticing the starter means: to tap the ignition button super fast to make the starter tic. LOL.
Going to do my valves tomorrow and hopefully that kills a lot of the bogging and idling problems!
Can't wait to actually get my new enricher as well.
Getting close.
Wish me luck guys and thanks for all the help.
PS: If you have any suggestions please feel free to offer them!

[Alleyoop]

Pop1205,
Easy way to turn the engine over so you can adjust your valves is Take the CVT cover OFF and put a SOCKET on the VARIATOR NUT and TURN it Counter Clockwise and you will get the Piston TOP DEAD CENTER very easy and your valves will be OFF the High Lobe of the CAM.
At this point you should be able to move the Rocker Arm with your fingers THEN adjust them.

But reading on what your saying you have Fuel Delivery problems as well. So after you adjust your valves it probably will run better but still the Carb will have to be adjusted once you get the New Enricher. The Enricher is only going to help in Cooler weather when the engine needs more fuel to start and run when cold.
But lets wait until you adjust your Valves and get the Enricher in. Then we can work on adjusting the Carb to stop the bogging.
Alleyoop

[pop1205]

Geesh man! This is taking too much time. I spend more time fixing than riding I need this scoot for school and I'm finding myself missing more and more because of this darn thing.
About taking the cvt cover off. Can't. Don't have a screw driver big enough. Have a nubby and many other average sized philips but no big sized ones. That's why I was going to tic the starter like the other fellow suggested. Would I need to adjust my gas to air mixture on my carb?

[pop1205]

Would this be the correct enricher to order? Just want to make sure before I go spend this little bit of money I do have.
www.roketapartsonline.com/electric-choke-assembly-for-chinese-250cc-engines-p-10093.html

[Alleyoop]

Hitting the starter to turn it over to get it TOP DEAD CENTER 99.9% IT WILL NOT STOP at TOP DEAD CENTER. So doing it that way you are wasting your time.

Another way is to take off the cover on the Fan which is attached to your Flywheel, that is on the side of the muffler. Then Turn that Counter Clockwise to get it to TOP DEAD CENTER.

You are going to have to get some tools if you are going to work on it yourself. A socket set that goes to 18mm, some pliers, screwdrivers etc..


Yes that is the right enricher. And yes you will need to adjust your Air/Fuel Mixture on the Carb. But that is very easy to do.
You want the engine to be nice and HOT take it for a ride or whatever then leave it running and adjust your Air/Fuel mixture.

What you want is to get the HIGHEST RPMS out of the Air/Fuel Mixture. So if your scoot does not have a tach you will have to listen for the RPM changes. From where it is currently set at.

1. Turn the Air/Fuel Mixture Screw Counter Clockwise 1/4 Turn.
a. If the Engine RPMS go up REPEAT step 1.
b. If the Engine RPMS go down or there is no change Turn the Air/Fuel Mixture Clockwise 1/8 turn and go to STEP 3.

*** IF ON THE FIREST 1/4 TURN COUNTER CLOCKWISE the RPMS go down TURN IT CLOCKWISE 1/4 TURN and go to STEP 2.***

2. Turn the Air/Fuel Mixture Screw Clockwise 1/4 Turn.
a. If the Engine RPMS go up REPEAT step 2.
b. If the Engine RPMS go down or there is no change Turn the Air/Fuel Mixture Counter clockwise 1/8 turn go to STEP 3.

3. Now set your IDLE SPEED you want it to Idle to JUST ABOUT when your REAR WHEEL wants to turn.

4. Now give the Throttle a QUICK half twist, it should not hesitate and or bog the RPMS should climb quickly, You should get a nice VROOOOOOOOOOM and then come down smooth back to the Idle Speed that you set.
Alleyoop

[speedracer]

Pop I have the same scooter and at 2000 rpm's the rear tire does not spin. I think you have 1600 miles on it and I have just turned 1500 on mine. If you are going to adjust your valves then you will need a 19mm socket to turn the variator. I know you lost most of your antifreeze thinking you were removing the value cover. Have you flushed the entire system out and then added a 50/50 Prestone mix? Another thing have you checked and or changed all of your fuel lines and vacuum lines. It looks like the previous owner did nothing before he sold it to you. A small hole in the vacuum line is going to give you hard starting problems.

Taking the cvt cover off requires you to remove the bottom plastic panel, removing a few screws which hold on the air filter, and then removing about 10 bolts which are 8mm in size.

Get some plastic bags and as you remove a part put them in a bag and label it. Take a camera and snap pictures so you can refer to them when putting parts back on.

My scoot will idle smooth from 1800- 2000 rpm's and not spin the back tire when on the center stand. If your scooter is spinning the back tire at 2000 rpms then you do need to remove the cvt and find out why the clutch is engaging at that speed. Mine will engage the rear wheel at about 2800 rpms.

To be honest with you, I'm not sure if you have a Roketa 54B or another model, nor am I sure what you have done with the PDI. I know this is all Greek to you, and most of it is all Greek to me as well.

Alley is right about you having a fuel delivery problem. Have you changed the gas filter? Check all the vacuum lines. I don't think you have any fuel leaks as you would smell gas and worse case set the scoot on fire.

[pop1205]

Hey guys, thanks for all the replys. Well went to advance auto and bought some tools and took the CVT cover and saw the big nut. Used my 19mm socket to turn it and it was quite easy to turn. So I adjusted my vavles, kind of tricky. But after doing it, my scoot starts on the first crank!!!!!!!!!!!!!!!!! And stays on. Only thing is is that I hear a clicking sound. So I'm going to go back and re adjust. Tricky part is holding the adjuster while tightening the lock nut. Letting it warm down now so I can go re adjust. My scooter has 22xx miles on it now. Yes, refilled the coolant. My scoot looks just look the guide for the 257cc linhai valve adjustment posted my JR in the 250-300cc section. EXACTLY the same, same color as well LOL. But I am getting there, slowly but surely. It was pretty cool to see my scoot crank on the first try, and stay on nice and strong, and not die down or idle crazy low. It idles at about 2500 So I believe it could be the faulty choke I have, or maybe my idle screw. NOT SURE. Haven't gotten to adjusting that. Just here posting my progress while letting my engine cool down.
Thanks for all the help guys ;D