new problem spuders and won't stay running By seanstr (Read 6,445 times)

[seanstr]

Ok, then if getting new cdi does fix this, I'll atleast make scooter more rich, until tomorrow

[seanstr]

& how do u know I have an acv?

[Alleyoop]

Here is a picture of the ACV(decelerator Diaphgram).
Alleyoop

[seanstr]

OK, so the problems I have explained are all caused by acv?, nothing else. I haven't replaced the cdi should I still do that? Or is it the needle & diaphragm

[Alleyoop]

NO, it may not be the ACV.

Let me ask this WHEN DOES IT BACKFIRE?

When you give it Throttle?
When you let go of the Throttle?

Did you check the HEADER FLANGE(Exhaust Pipe) connected to the MOTOR to check if the nuts are on and it is nice and snuge?

Take a picture of the Carb Area so we can see what we are dealing with, Take several pictures Right Side and Left Side so we can see the hoses and the Carb.
Alleyoop

[seanstr]

I don't have an acv, cdi was some of the problem, lean also, think exhaust valve adjustment needs to be re adjusted

[seanstr]

I messed with air fuel mixture, so that could be the problem, also I think maybe I didn't have the right valve settings, so I re-do that, & if that doesn't do it, I'll order a new muffler, cuz isn't so muffled, still quite loud

[seanstr]

I'll look for the acv valve then too, take pictures & everything

[Alleyoop]

If it quite LOUD now the problem could be that the Header Pipe is LEAKING where it connects to the MOTOR that is what you need to check before you order a new muffler? If the Pipe is loose by the motor that will CAUSE THE BACKFIRES when you LET GO OF THE THROTTLE.

Do not JUST THROW parts at it you can waste a lot of money doing that. IF YOU WOULD check what we are telling you to check you can save yourself a lot of money PLUS learn a lot on how to fix your scoot.

Here is how to adjust your FUEL RATIO MIXTURE SCREW:
Do it like this and take your time.
Alleyoop
ADJUSTING YOUR FUEL RATIO SCREW:

FOLLOW THIS PROCEDURE, take your time DO NOT Be turning the SCREW fast and wait in between turns otherwise you will be off.

Warm Up the SCOOT for at least 5 minutes.

YOU WANT THE HIGHEST IDLE OUT OF THE FUEL RATIO SCREW YOU CAN GET.

ADJUST YOUR FUEL RATIO:

1. Turn the Fuel Ratio Screw Counter Clockwise 1/4 and wait 10-15 seconds to allow the engine to catch up with the new setting.

** IF ON THE FIRST TURN IT DOES NOTHING OR IDLE GOES DOWN- GO to 2.*** Otherwise GO to a. below.

a. If the IDLE GOES up repeat 1.
b. If the IDLE does not go up or it does nothing turn the Fuel Ratio Screw 1/8 Clockwise that should be the highest IDLE you can get out of the Fuel Ratio Screw-- GO to FINISH UP.

2. Turn the Screw Back 1/4 and GO to 3..

3. Turn the Fuel Ratio Screw Clockwise 1/4 and wait 10-15 seconds to allow the engine to catch up with the new setting.

** IF ON THE FIRST TURN IT DOES NOTHING YOUR PILOT JET AND OR PASSAGES ARE CLOGGED*** GO to CLEAN CARB*** Otherwise GO to a. below.

a. If the IDLE GOES up repeat 3.
b. If the IDLE does not go up or it does nothing turn the Fuel Ratio Screw 1/8 Counter Clockwise that should be the highest IDLE you can get out of the Fuel Ratio Screw-- GO to FINISH UP.

FINISH UP:
SET IDLE USING IDLE SPEED SCREW:
USING the IDLE SPEED SCREW set the Idle to 1500-1800 where it IDLES the smoothest AND the REAR WHEEL IS NOT Spinning-

TEST YOUR ADJUSTMENT:
Now while on the Center Stand GIVE THE THROTTLE a GOOD QUICK TWIST and Let go,
It should REV UP with with a nice VROOOOOOOOOM with no Bogging or Hesitation and Come back down to where you set your Idle.
DONE RIDE SAFE.

CLEAN CARB:
Take Carb Bowl off and clean Pilot Jet and Pilot Jet Passage and Main Jet and Passage.
Then come back and repeat this procedure.

[Bashan]

Everything those guys said should be considered. Everybody has an air cut valve (ACV), it's on the right side of the carburetor with a vac line running into it, you can't miss it. Rich

[seanstr]

I agree, I remember there bring the the hose that attaches to acv, so I have one, I'll try everything, muffler too. Cdi was bad, it don't die now. Runs more constistantly. But still backfires. As for muffler, it's got a problem & I'm replacing it. I set both valves a month ago or so to .006.

[Bashan]

It's a 150cc right? That's kinda wide on the valves. I'd go .004" on both or maybe open the exhaust a little wider to .005".

I've been informed that some scooters do not have an ACV valve. If you have a GY6 with a vac line running to the right side of the carb it's an ACV. If not, you don't have one. Rich

[seanstr]

Right, I do Rich, there is an acv valve. Now I need to order one, & the muffler tomorrow

[seanstr]

Whom will have the acv, so far no one does

[Alleyoop]

Seanstr,
Why do you think it is your ACV diaphgram They rarely go bad. I think it is your HEADER PIPE LEAKING that is causeing the backfire Also if it is idleing to low it should be idleing about 1500-1800 rpms.

If you do find one they are expensive and you would be better off buying a NEW carb for under $50.00 bucks. BUT LIKE i said i do not think the backfireing is being caused by your ACV.
Alleyoop