|
|
Post by bigdew on Jan 6, 2009 0:12:08 GMT -5
yeah i know roketa,it is a MC-07-50 i posted on another forum and got nothing but grief but i paid 85 bucks for it and its like new, my problem is that when i start it it runs for a few seconds then dies the it will start back up and do the same thing, now i am pretty mechanically inclined and this stumps me cause it does start , i checked all the hoses and the seem to be tight , i also found 2 hoses not connected one comes from the front left side of the valve cover, and the other is a large hose that goes thru some sort of valve on the passenger side of the engine and has a filter on it , and i have no idea where it goes , the small one i think goes to the air filter intake but im not sue , the large i just cant find any place for it if some one could get me some shots i would be grateful  the scooter has just over 1000 miles on it and it is in great shape so i would like to try to fix it , the engine shows as a 1P39QMB so i have no idea what that means but "help"  there is no hose on the above valve coming off the air filter cover  this valve on the intake but it looks to be plugged from the factory  there is an unconnected hose coming off the valve cover above today i pulled the carb and cleaned it out not very dirty at all , float and needle valve worked well , i think that the fuel line is 3/16th I.D., but not sure i cut a piece off will go to store tomorrow to get new line and clamps, so till tomorrow |
|
|
|
Post by cruiser66 on Jan 6, 2009 1:15:58 GMT -5
Welcome bigdew, As far as I can figure from your description, these hoses are more for emission purposes than anything else. Many members will let the air filter hose run open when upgrading the intake system and disable the other hose when going to a big bore kit or a performance exhaust. I don't think these hoses are the reason for the problem you have. I would lean toward fuel delivery problems. The OEM fuel line can deteriorate and but crap in the carb. I would drain the carb (hose runs from bottom of carb) and see if the gas is clean. Fuel filter might be plugged also. A weak vacuum fuel valve at the outlet of the gas tank or a leak in the vacuum line to the valve could cause a problem. Also check for sediment or water in the gas tank. This link might help you out also: motor.mortch.com/support/scooter/engine/139qmb.pdfIt's a good idea to change the fuel line and filter to a better grade to eliminate any future problems. Good Luck, 66 |
|
|
|
Post by ScootGuy on Jan 6, 2009 5:31:57 GMT -5
Have to agree with 66.
If you have not changed you fuel lines and filter, and your vacuum lines, I suggest you measure out how much of each you need, cut a short piece of each off and take them to you local auto parts store and buy some new line. also, it would be a good idea to get new clamps for all of them.
I had the same problem with mine until I did this, once all the lines and filter was replaced and clamped with good clamps, it would actually stay running.
If your fuel lines were never replaced, you may have to clean your carb out from all the crap that came off the insides of the old lines, but, you may get away with some carb cleaner, get a can of seafoam and run through it, but, only after you put the new lines on, it will just make the cheap lines deteriorate faster and cause more problems with the cheap lines.
Don't forget to drain your carb after replacing the lines, there should be a drain screw with a hose connected on the bottom of your carb, crack it open and allow all the gas to drain out. Drain it into a container so you can look at it and see if it is clean or full of dirt.
|
|
|
|
Post by leo on Jan 6, 2009 8:09:26 GMT -5
if it starts but won't run then you have a vacuum leak.
check your intake for cracks.
without pictures to your setup i can't say where the hoses you mention go.
i would imagine that the unconnected hoses are the some of the reasons for the lost vacuum.
i would also change the spark plug.
|
|
|
|
Post by indy50 on Jan 6, 2009 10:58:47 GMT -5
If all the above doesn't help , then check valve lash. Maladjusted valves are often the culprit to many symptoms. (.004 intake and exhaust)
|
|
|
|
Post by rapidjim on Jan 6, 2009 17:44:01 GMT -5
Here are some basic ideas to check first on a Roketa 50. I am mentioning some that has already been mentioned so bear with me please ( and not to step on anyones toes).
Before we sell a Roketa Scooter this is what we do:
As already mentioned, check and or replace all fuel ines vacuum lines and fuel filter.
Change out Chinese Spark plug if not already done.
Change fuse holder to "spade type" car holder and fuse, Roketa uses a "cheap" fuse holder and the wires have a tendency to cause a bad connection and causes all kinds of problems.
Since this is a used bike, definately drain the gas from the tank and carb as previously mentioned. Use only top quality fuel, these motors "hate" cheap fuel. Using Sea Foam is also a very good idea.
After that try and run the machine again.
If you are still having problems, I have a sneaky idea the problem is either a dirty carb, ie junk in the jets, or possibly a bad electric choke.
Lets us know and happy scooting.
Jim/Owner Rapid Repair
|
|
|
|
Post by Enviromoto on Jan 6, 2009 22:57:16 GMT -5
$20 bucks its the valve lash.
|
|
|
|
Post by leo on Jan 7, 2009 9:07:44 GMT -5
the pictures aren't much help. what connects to the large diameter hose at the bottom of the pic? i have no idea what you are trying to show me here. this looks like it might be an external oil line. if it isn't then it's a vent line and shouldn't connect to anything, well the crankcase vent tube is teed to it. does the hose in the pic connect to the crankcase and does oil come out of it with the engine running? CAUTION: don't run your engine without oil. if oil starts squirting out of the hose then immediately shut your scoot off then put the hose back on. if there is no oil coming out and the hose is connected directly to the crankcase then you need a brass tee in there somewhere. |
|
|
|
Post by Enviromoto on Jan 7, 2009 14:38:12 GMT -5
|
|
|
|
Post by Troll on Jan 7, 2009 15:53:45 GMT -5
yeah i know roketa,it is a MC-07-50 i posted on another forum and got nothing but grief but i paid 85 bucks for it and its like new, my problem is that when i start it it runs for a few seconds then dies the it will start back up and do the same thing, now i am pretty mechanically inclined and this stumps me cause it does start , i checked all the hoses and the seem to be tight , i also found 2 hoses not connected one comes from the front left side of the valve cover, and the other is a large hose that goes thru some sort of valve on the passenger side of the engine and has a filter on it , and i have no idea where it goes , the small one i think goes to the air filter intake but im not sue , the large i just cant find any place for it if some one could get me some shots i would be grateful the scooter has just over 1000 miles on it and it is in great shape so i would like to try to fix it , the engine shows as a 1P39QMB so i have no idea what that means but "help" there is no hose on the above valve coming off the air filter cover this valve on the intake but it looks to be plugged from the factory there is an unconnected hose coming off the valve cover above today i pulled the carb and cleaned it out not very dirty at all , float and needle valve worked well , i think that the fuel line is 3/16th I.D., but not sure i cut a piece off will go to store tomorrow to get new line and clamps, so till tomorrow The set up is the same as my scoot, in the first pic the tit coming off the tube going in the air box that's where the hose off the crank case goes. The tit on the tube that goes to carb is going to be capped off from the factory, so the tube in the last pic should be long enough to reach what I was talking about in the first pic. |
|
|
|
Post by Troll on Jan 7, 2009 15:54:48 GMT -5
Also listen to Enviromoto and adjust your valves
|
|
|
|
Post by bigdew on Jan 7, 2009 19:39:36 GMT -5
thanks guys i really appreciate your help
|
|
|
|
Post by cruiser66 on Jan 7, 2009 20:32:17 GMT -5
Here's a shot of the crankcase breather hose from the top of the valve cover to the air intake. You can see the blocked off nipple on the air tube going to the carb. My scoot also has the 1P39QMB engine.  66 |
|
|
|
Post by bigdew on Jan 10, 2009 18:55:12 GMT -5
thank you i really appreciate it
|
|
the scooter has just over 1000 miles on it and it is in great shape so i would like to try to fix it , the engine shows as a 1P39QMB so i have no idea what that means but "help"
