150cc gy6 engine problems By blazef20 (Read 39,057 times)

[Alleyoop]

Blazef20,
No need to thank me, I am just glad I was able to help with your situation. I was Hot Rodder in the old days and used to Run my Hot Rod every Sunday at the Drag Strip used to re-build my Carbs, Engine and Rear Ends:)

As far as the fuel shut off If your going to stick with the Gravity Fed I would get a Shut off Valve. Reason being is in Hot weather it may start flooding the Carb when shut down. So this way when you park it you can shut the fuel flow off to the carb.
Alleyoop

[LUKE]

good to hear you have fixed your scoot blaze!! congrats...

i'd like to share my friend's dilema here, i don''t want to put up a new thread cuz the problem is basically ,almost the same...

my friend had been salivating in riding a scooter since he came to the US last year..he's been seeing me riding and wanted to buy one for himself...i actually got him to scootering..

so it happened,,,he bought a brand new 150cc mc150-60 velocity scooter ,he picked it up from california...he brought it straight to my house from cali.. i nstalled the brand new battery and tried to start the scooter... guess what...it didn't start..it crank but did'nt start,as if gas is not reaching the combustion chamber....
what i did:
1) thinking that the petcock is bad,, i bypass the gas line straight from the tank to the carb...still same problem
2) i remove the air filter rubber that was attached to the carb,cover the carb inlet with my palm and crank it,,it starts!!,,,the engine doesn't run smooth,,everytime i release the throttle ,it dies.. NO IDLE,,so i went to the next thing which is the air/fuel mixture...i adjust it ,and crank to test it several times...but still there's no idle...
3) i remove the top part of the carb to check if there are cracks on the diaphragm,,,nope,the diaphragm is in A1 condition.
4) i open the carb,check the float,,seems ok, carb is brand new..mint condition.,,no gums whatever.
5)i check the electronic choke,,,remove it...seems perfect condition...and it feels warm so i'm sure it's not shot.
6)i check for vacuum leaks,,,but i didn't see any,,,,all the lines are new and intact no cracks whatsoever.

i been warning him about buying that kind of scoot but..he's young and kind of hard headed...
well guys hope you can help us in our problem....i've probably done all...the only thing i didn't do is the valve clearance adjustment but ,do you think it's a valve clearance issue?? hope not..

thanks in advance for your assistance....i post this issue in detail only here in scooterdoc..

sorry guys,,i really feel bad today about this scooter,,the fact that it is a brand new scoot and it doesn't run.....just pisses me off..

[LUKE]

zzzzzz...

[Alleyoop]

Luke,
Well you already have a good clue of what is wrong . When you said you took the air filter off and put your hand over the Air Inlet and it started. That means you are not getting GAS. What you did by doing that is actually CHOKEING it. So first thing would be to Adjust the Valves since when it started it did not run smoothly. Then take the Carb off and check for blockish in the Pilot Jet. Spray Carb Cleaner into the Pilot Jet and Spray should be comeing out in front of the Carb by those little holes by the Butterfly. You also want to take out the Air/Fuel mixture screw completely out and make sure the tiny Rubber O-ring and washer come out Then Spray in there and spray should come out by the Butterfly as well.
Alleyoop

[blazef20]

exactly what i was thinkin alley try to adjust the valves. its really not that hard look in the tech section there is some great videos and step bys on how to do this. i did mine and it ran top. But guys to let you know i had something else deadly wrong. I drove to work yesterday fine. the way home NOT SO FINE. Halfway home the motor went. heard a TICK TICK. pulled over and it went away. started goin and about 10 ft. the motor seized up. so im gona take it apart and see what happened. Pretty sure motor is toasted but im curious.

[LUKE]

gosh,,hope it's not the timing chain...
i'll try to adjust the valve tomorrow....and see what happens..thanks Alley and blaze!!

[Alleyoop]

Blazefr20,
Well since you heard TICKING as you were riding it It could JUST be that the valves lock nuts came really loose and therefore the valves are not opening at all(HOPE THAT IS ALL THAT IS WRONG). When adjusting the valves make sure you tighten the Lock Nut down good, now you can overtighten them and strip and or break the little adjuster but that is a cheap fix.
Alleyoop

[blazef20]

ill have to check that im gonna go out tomorrow and check it over if not i found a 250cc w/ reverse so if i cant save it im gonna get that

[mflorek]

I got a kick out of reading this story. I recently worked on this very chassis. Very much like a scooter GY6 ‘cept the exhaust goes out the belt side of the engine. The buggy had been abused badly and the timing chain was skipped. I removed the cam and got the chain right. With the plug out, I spun the engine over a few revolutions to allow the chain tensioner to set and checked again. With the timing marks aligned, adjusted the valves. A splash of fuel and it started. Biggest problem with working on a buggy is no center stand. Rev too much and off it goes. Almost smashed the side of my wife’s Avalon!

[blazef20]

wow mflorek. did it a couple times to my truck put a big dent in the side of it. i really havent had time for the gy6. snow sux!!!! after i put the buggy in the side of the truck i put it on blocks (rear end). But im inclined to belive the motor did not seize. The motor is always turning its got reverse and drive no neutral when i pull it backwards the chain turns the engine. if it was seized it would not turn right? the tires would lock up wouldnt they

[Alleyoop]

If it has no Neutral you are correct, the motor is turning. You can also take the CVT cover off and turn the Variator with your hand, the shaft is the Crankshaft which has the piston connected to it and as you turn the Variator you are actually moveing the piston up and down. If it is really easy to turn with no resistance at all then there is something wrong, like no compression, rings bad, valves stuck open, hopefully no damage to the piston etc..
Alleyoop

[joeangel]

This thread has a TON of great info!

[manuels0711]

Dec 21, 2010 20:56:02 GMT -6 blazef20 said:

I have a gy6 engine im having probs. I cant start it. it tries it makes this wierd sound like it gurgles when i try to start it sounds like bubbles.i mean it turned on before it had that same problem I was riding just 3 days ago but now it won't start anymore. I kill my battery trying to start it but it just won't start.any help please any tips on what to do thanks

[manuels0711]

I have a GY6 dazon buggy I'm having trouble starting it.when I try to start it it makes this weird sound like bubbles. It turns but wont start.It uses to turn on with that problem but now it just won't start.I kill my battery trying to start it and still won't tried jump starting killed the car battery as well just won't start I don't what's wrong with my buggy any help or tips would help thanks

[manuels0711]

I have a GY6 dazon buggy I'm having trouble starting it.when I try to start it it makes this weird sound like bubbles. It turns but wont start.It uses to turn on with that problem but now it just won't start.I kill my battery trying to start it and still won't tried jump starting killed the car battery as well just won't start I don't what's wrong with my buggy any help or tips would help thanks