50cc Gy6 won't go above 10mph By grizzly (Read 1,552 times)

[grizzly]

Hi all,

I cleaned out my carb with carb cleaner, and now my scooter won't go above 10mph. It speeds up fine on the stand, but when I'm sitting on it it doesn't get any real speed going. No bucking or kicking, it just speeds up to 10mph and cruises smoothly at that speed. Any ideas?

[Alleyoop]

Yes I have some ideas of what could be wrong.
1. Did you take the top off the carb and take out the diaphgram?
2. Did you mess with the Fuel Ratio Mixture Screw?
3. Did you attach the throttle cable correctly and adjust it?

Take a picture of the RIGHT SIDE of the CARB LIKE THIS:
Alleyoop

[grizzly]

1. I did take out the diaphragm, though I was careful to put it back as it was.
2. I tried adjusting the fuel ratio screw, but only after giving it the test ride where it wouldn't go above 10mph. I gave it a half turn to the right and it didn't give any noticeable change.
3. I didn't actually remove the throttle cable, I just popped the rest off and sprayed it out. I didn't trust myself to remove the cable and get it back on properly.

[Alleyoop]

Cool, your problem is you have a very bad air leak your INTAKE MANIFOLD is all cracked you need a new INTAKE MANIFOLD.
Alleyoop

CLICK TO EXPAND THE PIC:

[grizzly]

Thanks, I was wondering if that might be a problem.

[Alleyoop]

You can patch it up with RTV it turns into rubber and then wrap some tape over that whole area while you order the new intake and wait for it to arrive. You can get the RTV at any auto parts store.

[grizzly]

Perfect! I'll do that first to make sure thats my problem, though I'll ordre a new one either way.

[Alleyoop]

Cool, let me know if that is ALL that is wrong with it. But that certainly is a major BOG issue and will run much better after it is fixed. Just remember any AIR LEAKS will cause the motor to suck in to much air for the amount of fuel so it will not take throttle very well.
Alleyoop

[grizzly]

Apologies for the long delay.

Alright, after stupidly ordering a new intake Manifold from China, I've been waiting a full month for it to come in, and hopefully I'll see it in the next week or 2. I thought I'd be patient and save a bit of money in the long run instead of patching it, but gave up on that this week. I took off the intake and patched it per directions, though looking on the inside I don't see the cracks making it through to the other side. Still not getting it to go above 10mph.

I didn't take off the throttle cable before, but maybe adjusting it might help? On the stand it gets the power it used to, vibrating with enough power to turn the scooter in circles if I don't brace it while revving.

[trashtruck12172]

check the throttle cable itself for fraying, stretching or binding.

[cyborg]

It may have a carb problem,,,it happened when you cleaned it,,,,,Venturi jet may have fallen out and you didn't notice or the main jet is partially plugged

[grizzly]

Checked the Throttle cable, no wearing anywhere.

[grizzly]

Jun 6, 2016 21:32:54 GMT -6 cyborg said:

It may have a carb problem,,,it happened when you cleaned it,,,,,Venturi jet may have fallen out and you didn't notice or the main jet is partially plugged

I should note, the reason I even went through cleaning it was that during the winter the petcock failed and leaked through the whole system and filled up the oil.

[grizzly]

OK, an update. I went ahead and bought a new carb, as I didn't want to bungle around with the old one any more.

Trouble now is I'm not getting it to start at all, I'm not convinced its getting any gas, though when I hit the starter I see movement in the fuel filter, like the fuel in it is bouncing around and an bubble here and there, which I take to be a bad sign. The only things I didn't hook up were the fuel overflow hose and the drain hose, but I assume those don't go to anything.

Pulled out my spark plug and tested it on the frame, got a spark no problem.

[cyborg]

Pull the plug agAin and put a teaspoon of gas in the hole reinsert plug and see if she'll pop,, I'm sure she will,,, then it's a fuel delivery problem