At witts end. Buying a new scoot! By twowheeler (Read 836 times)

[twowheeler]

From day one I have had an off the line sputter that just wont go away. Cracking the throttle 1/8 inch or so it just sputters then takes off. Its too annoying and i have thrown everything at it to no avail....it has 2000 miles on it.


New NGK plugs (2), coils (2), cdi's (2)
3 different carbs, 3 sizes of pilots jets 30, 33, 35 in each all brand new and no change
Every possible AF position
2 fuel filters, all fuel lines.
New air cleaner assembly and filters.
Valves set

Checked for air leaks and nothing.

Theres a Gremlin affoot here and I just cant figure it out. so Im baling on this one.

[jct842]

did you use spray to check for leaks? Some use water, some use carb cleaner or ether. I use what ever is closest usually ether.

[twowheeler]

I have. I have a gravity fed fuel supply with a petcock bypass and all of the vacuum ports are plugged well. The only other place to check for leaks would be the intake elbow and alls well there....maybe since i have no other vacuum operated functions, the diaphram and slide in the carb is getting too much vacuum and causing this?

[kz1000st]

Does the carb have an accelerator pump?

[twowheeler]

2 do and 1 doesnt. Even tried disabling the pump where it didnt depress and didnt change anything. Both were new carbs so they were probably working fine. I didnt use the same enricher either when changing out the carbs but used the ones that came with them.

[LUKE]

check the stupid petcock and carb float,,seems to me that it's flooding the plugs everytime you hit the throttle...
Now you are experiencing the bad side of the chinese scooter, it's not the worst YET,,,the worst is yet to come., be ready!!! You keep on buying parts etc but you're not solving the problem, it's sucking up your wallet man!.,that's what happened to malevelina remember?, now she has the guts to ride the red trike from phoenix to lake tahoe,, my goodness!!....

i said it once, and i'll say it again----> chino scoot gives you nothing but Headache...

WAKE UP!!!!





don't ever think that im a bad person....,,,i still wish you good luck!!

[scooter49]

My 250cc scooter never sucked my wallet. All together, besides insurance money to replace cosmetic parts when it blew over in a windstorm, I only thrown regular maintenance into it. Over 7000 miles on it and still running strong. Chinese don't make bad scooters. People can abuse them by running hard and not giving breaks. I rode from Jefferson City Missouri to Quincy IL.. took breaks about every 40 miles. Made the trip great. Rode a lot of long trips and gave breaks about every 40 miles. But anyhow, these machines are not meant for abuse. Meaning they are expected to have regular maintenance: oil changes, antifreeze checked, gear oil changed, brakes checked, valves checked, ect.. I am working on mine half the time doing maintenance. Maintenance takes time to do. Tear the body panels off to get to a darn plug.. But it has to be done. Maintenance has to be done whether Chinese, Japanese, Korean, ect.. I kept full coverage insurance on it, since owning it.

[kz1000st]

No it isn't too rich, it's lean. He's not getting fuel. It sounds like an old Ford I had with a limp accelerator pump. I had to do two quick stabs at the accelerator before speeding up or it would stall. I would try a couple of small, quick yanks on the throttle before taking off and see if it changes things. Not enough to activate the clutch but enough to squirt fuel in.

Also what's the idle speed set at? The 50cc I had was practically screaming to my ears. Your stumble could be too little engine speed to haul yourself off the line. It's only three horsepower.

[twowheeler]

My old scooter came by for some work on the body and i know that carb was perfect. I put it on mine and same damned thing.

[cyborg]

Ignition,,? too advanced? I think you can eliminate fuel issues with4 carbs tried and you know the last one is perfect

[cyborg]

Timing chain loose? Automatic tensioner? Spring bad?,, seen that one with similar symptoms

[cyborg]

I hate these nittley little snags,,, you don't even have to pull your hair out it'll just fall out on it's own,,

[Alleyoop]

If it sputters it is a fuel problem. Now that can be caused by a bad gaped plug.
Alleyoop

[cyborg]

Yea bad plug incorrect gap,,, I don't see the fuel issue 4 carbs one known to be set up correctly,, coil maybe going away?cdi not sending correct signal at low rpm? Idle set too low as KZ suggested?

[kz1000st]

I would crank up the idle speed and see what happens. If it goes away it's either bad vacuum or some fluky electrical problem. If you put a voltmeter across the battery at idle what does it read? It could be something fluky like a stator or signal sender at the flywheel, what do they call that?

And I know you're pretty sure you covered all your bases but I would listen real carefully as the engine runs and listen for hissing. One of those ports you plugged might not be. Forget water, spray around with WD-40 and see if the engine idle changes.