50cc scooter not starting By myhotdelta88 (Read 1,921 times)

[myhotdelta88]

A friend brought me two Ishi? 50cc scooters. The first was he bought not knowing how long it has run. I read the post with the descriptions of taking the carb off and cleaning it. Checking to see if fuel spurts out of line when cranking. It does. It also has spark when plug is out and touching the motor. No battery though. Does this have any impact on starting? Any ideas about what to do next?

[phinchman]

How do you start a new post? I'm having trouble. The new topic link at the top isn't working.

Thanks, Philip

[tvnacman]

adjust the valves , pull the intake manifold off dump a table spoon of fuel in the intake and kick it started .
You don't need a battery to kick start the engine .

John

[Alleyoop]

Apr 2, 2013 18:38:22 GMT -6 phinchman said:

How do you start a new post? I'm having trouble. The new topic link at the top isn't working.

Thanks, Philip

GO TO WHATEVER SECTION if its this section CLICK ON NEW THREAD Put your SUBJECT TITLE then type in whatever and click on modify post.
Alleyoop

[jwalter042]

Make sure you clean the carb. completely (i.e. take the jets out and make sure they're clean) I use a piece of brake cable to clean the jets. It should start (even if it's just for a moment) with starting fluid sprayed directly being that you're getting good spark. From there you can determine what needs to be adjusted. Altogether, check and make sure all gaskets are sealed properly, you can spray starting fluid on the gaskets when you get this running and listen for change in sound. Most importantly dump out all the old gas and oil before doing any cleaning so you don't clean the components and just put dirty gas and oil back into it.

[LUKE]

+10 JWALTER042

[myhotdelta88]

This seems all to familiar. I did this with my Puch mopeds and they are now running great. When I had the carb off, I didn't even think about tearing it down. It just slipped my mind. Fuel is flowing good through the hose and out of tanks when I crank on it. I will be changing the plug tomorrow and tearing the carb down to see what it looks like. Thanks for the help........

[Alleyoop]

MYhotdelta88,
The Pilot jet may be clogged and ITS PASSAGE as well as the TINY HOLES by the BUTTERFLY IF your carb is a CVK carb.
Here is what you want to do, get a can of carb cleaner they come with a long thin straw.
Take the JET out and make sure you can see DAYLIGHT through it.
Then With the JET out Stick the THIN straw into the hole and spray.
And here is where the spray should come out.
Alleyoop

CARB BOWL OFF:

[myhotdelta88]

Ok cleaned carb completely. There is spark. Not sure how strong it is. I can see good spark in the light while plug is out. Tried taking carb of and dropping some fuel down the intake and it still didn't start. Next is compression. Can the compression be the problem and what does it have to be at. This actually the second of two scooters with the same problem. One he was riding and it quit. The first was sitting for a long unknown time. I need to get at least one of them running. Any new ideas? Bad CDI? Out of time? But no timing with a CDI I believe. I am used to two stroke. Any Help???

[Alleyoop]

Did you check for spark ON THE MOTOR? many hold the plug on the frame which is not good enough. The battery is grounded to the frame BUT the motor ALSO has to be grounded to the frame and if the ground from motor to frame is not good the Spark Plug will not fire while in the motor.

One tell tell sign of no spark is crank it over and take the plug out if the spark plug is wet then you know it is not fireing. Since you put some gas directly down the intake it should of fired at least once so that points to NO SPARK or very LOW COMPRESSION or way out of time.

As for the Compression you hold the throttle wide open and crank it IF lower than 120psi not good. Also check the valves if they are tight you will loose compression because they are not closing. Set the Valve gap to .003 or .004 inchs.

The timing is fixed on the Flywheel unless the Woodruff key is damaged which will throw off the timing. The only other thing that could throw off the timing is if the timing chain is loose and jumped a tooth or two. But you will be able to see a loose chain once you take the valve cover off.
Alleyoop

[LUKE]

alleyyyy!, why do you need to hold the throttle wide open when testing for compression?
why?

[Alleyoop]

Apr 4, 2013 11:48:07 GMT -6 LUKE said:

alleyyyy!, why do you need to hold the throttle wide open when testing for compression?
why?

You want it to suck in as much air as possible to create as much compression as possible, otherwise you will get a low reading.
Alleyoop

[LUKE]

you always amaze me with you mechanical expertise...ill remember that.

[myhotdelta88]

Ok cleaned the carb and poured some gas down the intake and she almost started. Coughed a couple of times then died. Sprayed some carb cleaner into the carb and again she coughed. So now what? I am getting drops of fuel down the line when craking but it seems nothing worth starting and keeping her running. ANything to do about making sure fuel is steady enough to run? AGain, thanks for all of the input, it all seems to be helping.

[Alleyoop]

Great, now we know it is not getting gas,
So first turn the FUEL RATIO SCREW clockwise until it stops and then turn it out 2 1/2 turns. That is a good starting point for any motor to get enough gas to start. If it starts let it run until the ENRICHER cuts off the extra fuel, the idle should come down to around 1500 rpms and hold.
Then you can adjust the FUEL RATIO MIXTURE to get the HIGHEST IDLE.

First try richen it COUNTER CLOCKWISE 1/4 turns at a time and see if the IDLE goes up, if it does reap the 1/4 turn. If on the first 1/4 turn it does nothing or goes down GO the other way LEAN it out 1/4 turn at a time. After you get the highest idle out of the mixture screw you can then lower the idle using the IDLE SPEEDS SCREW. Then try it out take it for a ride and crank on the sucker. It may need a minor adjustment to the carb but nothing major if it stumbles at any point giving it throttle.
Alleyoop