LinHai 260 Scooter.. No Spark By amossearan (Read 11,739 times)

[amossearan]

I have fire after replacing the pu coil, stator and coil..... but it seem's as if the spark is being compromised in some way .... unit is now bogging down again with the original ignition box ..... unit cold starts fine ..... but is now starting to backfire when I let off the throttle .... hmmmmm is this still an electrical issue compromising the signal to the ignition box and then breaking down the spark that is being produced by the coil? ...... by the way my flashers and turn signals are not working properly either (intermittently)

[amossearan]

Just back from a ride ...... when unit starts to die while sitting still, I pump the throttle and it picks back up ..... does not backfire when I decelerate from running @ 40-50 mph cruising speed and does not die if I keep the throttle opened up slightly while stopping @ intersection ..... if I'm sitting still and the unit dies, I pump the throttle a couple of times and it starts right up without having to grind on the starter ..... hmmmmmmm
Thanks in advance for your help .... tis most appreciated

[alleyoop]

Does your carb have a PUMP, because pumping the throttle with a pump what it does is squirt some gas into the intake. Have you adjusted your valves, symptoms of tight valves is not holding an idle after it gets hot so you need to give it throttle to keep it from dieing.

It appears it is running LEAN, also when does it backfire on deceleration or getting on the throttle. Check for AIR LEAKS especially by the Header Flange where your pipe connects to the motor.

If your valves are ok then you should adjust your Fuel Ratio Mixture RICHER, with the cold weather the motors need more fuel.
Alleyoop

[amossearan]

the carb does have a pump,valves have adjusted, backfire on deceleration from 65ish mph... I will increase fuel and ck the header flange

[amossearan]

Adjusted Fuel mix ..... checked flange .... idled and did not die ..... took it for a spin .... warmed up ..... idle's for about 10-15 sec then dies .. pump the throttle 1 time .... fires up, idles then I increase the throttle when it get's ready to die and it will keep running at an idle as long as I bump the throttle just before it dies.

[alleyoop]

What RPMS does it IDLE at , the idle may be set to low for the motor. The Idle should be around 1800-2000 try setting the Idle up without the REAR WHEEL SPINNING.
Alleyoop

[amossearan]

Idle RPMS has been set up

[alleyoop]

What did you set your Valve gaps to and at what rpms does it idle without any help before it dies. You have to give some DETAIL BRO, you say you did this and that but the DETAILS is what counts you can be doing it wrong. Also what type of FIlter is on there and do Take a picture of your CARB, DOES IT HAVE AN ACV VALVE?


You are running LEAN on deceleration if it backfires, and that can just be that the PILOT JET needs to be richened up. So if you are sure you DO NOT HAVE AIR LEAKS then turn the FUEL RATIO SCREW 1/2 turn Counter Clockwise and see if that stops the Backfireing when you let go of the throttle.


Also on the CENTER STAND give the Throttle a quick twist and let go:
Do the RPMS drop right away or Drop down slowly?

Alleyoop

[amossearan]

Not sure of the RPMS, but set just under the rear wheel spinning ..... valve gap 005-006 .... filter is an individual air filter; turned the fuel mix screw 1/2 turn clockwise and it has reduced the backfire when decelerating from 65-70 mph. The RPMS drop right away on the center stand, not sure about the ACV Valve .... will take pic of carb and filter. Cold start from setting overnight is as follows .... 1 quick pump of throttle, tap the ignition, fires right up and will idle for 4-5 minutes, when unit dies I pump the throttle once and restart and unit idles for about 10-15 seconds ..... i can pump the throttle at the point of it dying to keep unit running / idling .... so for now I just apply a small amount of throttle while holding the brake @ stop signs, unit accelerates and runs out fine until I release throttle and decelerate to an idle

[alleyoop]

Did you make a mistake SAYING you turned the FUEL RATIO SCREW 1/2 CLOCKWISE??

YOU NEED MORE FUEL you need to turn it COUNTER CLOCKWISE. If you did turn it Clockwise
NOW TURN IT COUNTER CLOCKWISE 1 FULL TURN.

Also your valves are to WIDE adjust both valves to .004 inchs to allow more air and fuel to be sucked in.
Alleyoop

[amossearan]

my mistake .... I should have said counter clockwise .... smell's really rich ..... still does not idle for more than 10-15 secs after warming up ..... I will get the valves readjusted to .004

[amossearan]

should I remove the carb, have it disassembled and cleaned thoroughly?

[amossearan]

I removed disassembled and cleaned carb .... removed and re installed the exhaust flange ..... unit fired up and was able to adjust idle / fuel and air mix ..... increased throttle RPMS up to 75% for about 20-30 seconds ( ran fine ) ..... increased throttle then released throttle and applied rear brake to simulate a stop, unit idled and did not shut off. Took off for a test ride .... unit shut off after about 1000 feet, restarted unit ... went another 500 feet .... died again ....... would restart .... I am now back to square one with No Spark.

[alleyoop]

Are you sure it is NO SPARK and NOT a Fuel Problem? Sure sounds like a fuel problem to me.

Lets check out the fuel delivery to the carb first:

CHECK FUEL DELIVERY:

Take the Carb Fuel hose off the Carb put it in a container and crank the motor over.

A. IF FUEL STREAMS OUT, fuel to the carb is good, Filter is not clogged and Petcock is working now

Re-connect the Fuel hose back onto the carb—GO TO CHECK CARB.

B. NO FUEL COMES OUT, take the Fuel Filter off and crank it again

a. If fuel comes out the Fuel Filter is Clogged.

b. If fuel does not come out –GO TO CHECK PETCOCK.



CHECK PETCOCK:

Take the Vacuum Line OFF going to the Petcock from near the carb and suck on the VACUUM LINE.

A. If fuel comes out you have a VACUUM PROBLEM.

B. If fuel does not come out you either have a bad petcock or a clog from the tank to the petcock.

Disconnect the fuel line going to the Petcock from the tank.

a. If fuel comes out the petcock is bad

b. If fuel does not come out either the hose from the tank is clogged or the tank outlet is clogged.



CHECK CARB:

First turn the Fuel Ratio Screw Clockwise until it stops and then turn it out Counter Clockwise 2 ½ turns

And try to start it.

A. If it does not want to start get a paper cup and put in about teaspoon of gas. Take the Vacuum hose off the

Intake Manifold squeeze the paper cup and make a point and pour the little bit of gas straight into the

Vacuum hose and connect the hose back onto the intake manifold. Now try to start it.

a. If it attempts to start or start and die now we know gas is not being sucked out from the carb bowl—

GO TO CLEAN CARB.

b. If it does nothing time to check for Spark and Compression.





CLEAN CARB:

Take the Carb Bowl off and unscrew the PILOT JET and MAIN JET.

First clean out the Jets make sure you can see Daylight through them.

Then Spray into the holes the Jets came out of and clear out the passages.

When you do this spray will come out of different areas. When you spray into the pilot jet spray will come out by the

front of the carb by the Butterfly. When you spray into the Main Jet spray will come out by the needle guide.
Alleyoop

Here is where Carb Cleaner Spray should come out when you spray through CLEANED JETS and PASSAGES.

Spraying into the MAIN JET:



Spraying into the PILOT JET:

[amossearan]

oops typo ...... I meant to say .... would not restart