MC-75-150 no spark By soda5187 (Read 3,497 times)

[soda5187]

Hi! I live in Austin, Texas and my fiancee recently bought a scooter. The scooter is Chinese and it has been giving us problems since day 1. It is a Roketa MC-75-150 (150cc) with 55 miles on it. It is not getting any spark. I have been working on it for a few days now -- the spark plug is fine and the power coil is fine. I have tried 2 different CDI's and it still doesn't work, so I could be wrong but that leaves only the stator, right? I got as far as removing the fan from the exhaust-side of the engine and then realized that the flywheel cover is pretty impossible to remove -- whenever I try to loosen the center bolt the whole thing turns! I tried putting the small peripheral bolts back in to try to hold them still with a screwdriver or something but the bolts just break! I read that I need to get an impact ratchet but 1) I don't have an air compressor 2) I don't have a whole lot of money to buy expensive power tools. Does anyone have any suggestions?

[mthomas]

Ha...I was just in Austin Texas for 4 days on business.
Nice area.
Cool bars.

[Bashan]

Aug 11, 2010 20:58:10 GMT -6 mthomas said:

Ha...I was just in Austin Texas for 4 days, nice area. Cool bars.

Astounding that you would find that the most exhilirating feature... ;D.

Soda, how are you sure it's not the coil? You gotta get an impact and a cheap strap wrench, the rubber ones work; I just did this two days ago. I think you may have your parts mixed up, the flywheel is right under the fan, and you need a puller. Hang on, I'm going to write up a tutorial but I'll go get you some pics off of the Nikon. Don't do anything until I get back....promise? Rich

[Bashan]

OK, rather than junk this up with a bunch of red squiggly lines I got a red dot to the inside of each fan bolt; are these what you twisted off? If so no biggie:



The red dots below are to the outside of rivets, not removable on my scooter. Do you have bolts here? I've never heard of that but anything is possible. The yellow dot is next to the flange bolt that must be removed with an impact IMO. By the way, just as an oddity, if you look above the blue dot you can see that just by chance the trigger magnet stopped exactly under the pick up coil. See it sticking up a little bit? Weird huh?:



Rubber strap wrench (red dot), you can see it wrapped around the flywheel; be careful of the pick up magnet. Pop it with the impact a couple times, 100psi. I think it was a 19mm, I'd have to go downstairs to look:



Flange bolt is off; screw puller main body (red) into LEFT THREADED flywheel, hold with crescent (green), and turn inside shaft of puller to right with ratchet (white):



Voila' it pops off and there's the stator:



Remove red, yellow, blue bolts, and the stator assembly lifts right out. The pick up coil has two (blue) bolts and is NOT adjustable:



One other pic; the red arrow points to the inside left threaded opening in the flywheel that the main body of the puller (blue arrow) goes into, the green arrow points to the shaft that pushes against the crank:

[Alleyoop]

Bashan,
You are AMAZING!!! What a FANTASTIC Tutorial, very straight forward, very simple, Great Pictures, JUST FOLLOW THE DOTS as they say, even I can do it:)

Thank you for taking the time, thats what helping is all about.
Put that in the Techy Database.
Alleyoop

[runningslow]

That beats the crap out of my flywheel removal tutorial. Feel free to replace it if you haven't already!

[Bashan]

Aug 12, 2010 11:51:41 GMT -6 runningslow said:

That beats the crap out of my flywheel removal tutorial. Feel free to replace it if you haven't already!

I'm not just saying this, I looked at your post and read it twice before I proceeded. I don't think I would have known how to start if I hadn't, yours stays my friend. Rich

[runningslow]

Aug 12, 2010 15:05:16 GMT -6 Bashan said:

Aug 12, 2010 11:51:41 GMT -6 runningslow said:

That beats the crap out of my flywheel removal tutorial. Feel free to replace it if you haven't already!

I'm not just saying this, I looked at your post and read it twice before I proceeded. I don't think I would have known how to start if I hadn't, yours stays my friend. Rich

Well, at least supplement it with your pics! My pics are crap!

[mapbike]

Bashan..........Very good instructions, very easy to see and understand, outstanding pic quality makes loads of difference.
Great job, Sir.

Shan