GY6 Engine coughed, then died By Steve (Read 9,710 times)

[Alleyoop]

Just post them on here JPG
Alleyoop

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[Steve]

[Alleyoop]

THAT IS GOOD BRO, adjust the valves at that position TOP INTAKE to .004 and BOTTOM you can also go .004 inchs or .005 inchs.
Good job
Alleyoop

[Steve]

It sounds better.

They are both set at .004. Hope that works!

I maneuvered the hose, thanks John aka tvnacman, and couldn't tell a difference in sound. When the carb was out a couple of weeks ago, I checked the connecting hoses and they seemed OK. Still no cracks/splits.

I gots to put it all back together and take her for a ride. Hope it's all better now...

I'll update y'all when I get back.

I really appreciate everybody's help and suggestions. I want ride this thing, not mess with it daily.

< Steve >

[Alleyoop]

Good job Steve, it should run better and if not we can adjust the carb now that the valves are set good.
Alleyoop

[Steve]

Just got back from a 9+ mile ride. (It's COLD - even in San Diego!) I think it's the longest I have ever been on!

I didn't hear anything funny. Let's hope it's fixed! for good!

Again, I thank all of you for sharing your knowledge and experience.

Maybe I can do the same someday.

Happy Scooting!

< Steve >

[Alleyoop]

FANTASTIC!! Have fun and enjoy the rides,
Ride Safe
Alleyoop

[tvnacman]

stock Chinese scooter engines are lean . Good luck !!!!!

John

[Steve]

WAIT!!!! It ain't fixed yet!!

Thought I would take it out for a confidence ride this evening. I got 3.5 miles down the road and it quit again. It took me 45 minutes to go the 3.5 miles back home. If you want the details, I'll type them out. I believe I have enough experience to know what causes my scooter to stop: it needs a valve adjustment.

No, I have not disassembled the scooter to measure the valves for verification. I can do it later. $20 says it's the exhaust adjustment.

This brings up the question: What can cause the valves to lose their adjustment?

I need y'alls help and suggestions again.

Thank you very much!

< Steve >

[Alleyoop]

You may not have tighten the lock nut enough would be my guess, because if you set them at .004 or .005 the head would not be so soft as to be compressed with a few miles.
So when you check the valves again check and see if the lock nuts are loose, and or check for a crack somewhere on the assembly that holds the rockers. Some have cracked on the right or left side where the metal is thinner between the BOLTS.
Alleyoop

[Steve]

All I want to do is ride...

The bolts holding on the cover were not torqued down very hard. They were not loose. But that shouldn't have any affect. Right?

I tightened the valve lock nuts last time with a ratchet. IN and EX were both .004. I just tried to move them with my fingers and neither would even budge. They are MORE than finger-tight.

I measured the gaps just now: IN - a 4; EX - a tight 3. Seems the one that is always changing (3 out of 3 times) is the EXHAUST. I can tighten it more!!

I don't know what I am looking for, but I used a flashlight and looked around the arms for some sign of a crack and found nothing. (whew!)

My thoughts? Set it at 4 again and CRANK IT DOWN. But - you guys have the experience...

What's my best next move?

Thanks, in advance!!

< Steve >

[Alleyoop]

Yea the valve cover just nice and snuge so the oil does not leak out, to not crank on them really hard they will either break or strip the head.

As far as the Valves are concerned set the EXHAUST to .005 inchs and leave the intake at alone it is fine at .004 inchs.
Alleyoop

[Steve]

tvnacman: What do mean when you say "stock Chinese scooter engines are lean . "?

Does that mean I should turn the air/fuel mixture screw in or out from the standard 2 1/2??

Thanks!

[Steve]

Should I try to tighten the lock nuts a bit tighter? It keeps moving. Even after the mechanic worked on it...

[Alleyoop]

Seblake,
2 1/2 turns is just a starting point, once it starts let it WARM up at least 5 minutes idleing and then you can fine tune the Fuel Ratio Mixture.
You want to get the HIGHEST IDLE when you finished adjusting it.

So from the 2 1/2 turn out:

1. Turn it 1/4 COUNTER CLOCKWISE(RICHER) and wait about 10 seconds to allow the motor to catch up with the new setting :
A If the idle goes up REPEAT #1 -- UNTIL the idle does not go up or drops a little--THEN TURN IT CLOCKWISE 1/8 of a turn--GO TO #3.

*** IF ON THE FIRST 1/4 turn COUNTER CLOCKWISE the IDLE DROPS or DOES NOTHING --TURN IT CLOCKWISE 1/4 AND GO to #2 ***


2. Turn it 1/4 CLOCKWISE(LEANER) and wait about 10 seconds to allow the motor to catch up with the new setting :
A If the idle goes up REPEAT #2 -- UNTIL the idle does not go up or drops a little--THEN TURN IT COUNTER CLOCKWISE 1/8 of a turn GO TO #3.

3. If at this time the REAR WHEEL IS SPINNING --Lower the IDLE USING THE IDLE SPEED SCREW, that is the one on the THROTTLE CABLE side that has a SPRING:
Turning it COUNTER CLOCKWISE LOWERS the IDLE so turn it so that the REAR WHEEL Just wants to TURN or around 1800-2000 rpms.
Alleyoop