Roketa Cayman now won't start By duffyman (Read 2,137 times)

[duffyman]

I got a used Cayman 150 and have not had much luck. After cleaning the carburetor and putting on a new auto choke, I got it running pretty good and was able to ride it around. After sitting for a couple of wet days, it would not start. Cranking and cranking got it to start but the engine would not rev past half way. Suspecting electrical trouble, I replaced the spark plug wire and coil. Then it would not start. I emptied the gas tank and found that the gas was nearly black! I put on a fuel filter cleaned the spark plug and re-cleaned the carb, but it will not turn over at all.

I am totally at a loss as to where to go next. Is there some type of fuse that could be blown. Its a real mystery as I got it running so good for a couple of days.

[Alleyoop]

First thing is check if your getting Spark. Take a spare spark plug and stick it in the coil Boot and hold the spark plug against the motor or valve cover and crank it see if it sparking.

If you get a nice blue spark then take the VACUUM HOSE off the MANIFOLD INTAKE and squirt some GAS down the nipple and put the hose back on. It should attempt to fire or even start and die. But if it does then it is a FUEL DELIVERY problem.
Give that a shot and let us know what happens.
Alleyoop

[sprocket]

When you replaced the ignition coil, did it come with a new lead and plug boot attached? Could very well be the spark plug boot , or if you replaced just the high tension wire you may not have it screwed in correctly at the boot or coil. You need to make sure that the copper wire is in contact with the screw..

Also the plug boot may not be making contact with the plug....need to check that too

[duffyman]

The spark wire came with the coil and the spark plug boot. contact with the plug seems good.

I finally got into the frigid cold garage and checked the spark. Sure enough, it was dark.

This is so strange as it was working fine, then went to no rev, then to dead in just a couple of days.

Anyway, I held the plug up to the valve cover as well as several other places on the frame just to make sure. Also tried it on the old wire and coil in case I somehow got a bad one. Even tried an older plug, but no joy.

Well guys, where to next?

[Alleyoop]

Well did you try taking the KILL SWITCH OFF the CDI, the kill switch may be the culprit and it is groundng it out. So unplug the KILL SWITCH WIRE from the CDI and see if you get a Spark.
Here is the Kill Switch Wire on the CDI.

No Spark,

1. KILL SWITCH
2. Side Stand
3. Boot Cap
4. Coil
5. CDI
6. Pick Up Coil
7. Stator

Alleyoop

[duffyman]

Is there a trick to getting just the top wire out of the harness or do I leave out the entire 2 line plug?

[sprocket]

You should be able to work the black/white wire out of the plug...the other wire must be plugged in...

[duffyman]

;D Looks like its working!

Seems the new coil had slightly thinner posts than the old, so the wire connectors did not make solid contact with the coil. When trying the old coil, I did not mount it to the frame, so no ground. Noticed while checking the wiring in general. Re-pinched the connectors and made good contact with the coil. Scooter starts, runs, and now accelorates better than ever!

Thanks for all the help, I would have never found it without scooterdoc and you guys.

[duffyman]

I'm back! This morning the scooter started after only one crank. I went to work, stayed a short day so I could take it to get its safety inspection. After only 5 hours since starting just this morning, it won't start.

I pulled the plug and it gets a bright blue spark. Opening the throttle wide, cranking, closing and cranking again, it gets a bout a half a hint of firing.

I don't understand how it breaks by sitting for just a few hours in the garage.

[bcgreatness]

Well that was short lived, it sounds to me like your having either another almost connected wire, or you have a fuel problem. Alley is our go to guy on the carbs.

[Alleyoop]

Since you were fixing things in there check to see if you accidently pulled a vacuum line off. See if you see a hose not connected.
If all is good and connected and your getting spark then it is fuel delivery problem.
To verify take the Vacuum line off the INTAKE MANIFOLD and squirt some GAS directly into the intake put the hose back on and see if it FIRES it may even start and then die but if it does then we know it it a fuel delivery problem and some tests have to be made to fine what part is causeing the fuel starvation.
Alleyoop
Here is a picture of what Hose to take off and squirt some gas directly into the Vacuum Manifold connector:

[duffyman]

I got it running but am not happy with how. I have to hold the throttle open a bit, then when it starts let it go and it will idle normally. Thinking maybe of a new pilot jet.

[Alleyoop]

No you do not need another pilot jet. Turn the Idle Speed screw a little CLOCKWISE to raise the Idle. That is what the IDLE SPEED screw actually does it is like turning the Throttle a little.
You can also try adjusting your carbs Fuel Ratio Screw.

You want the highest IDLE when your adjusting it. It could just be temperature changes in your area. If it got cold it needs more fuel to run right and start right. If it is HOT it needs Less Fuel to run right and start right.

So DO the Following:

Start the scoot and let it warm up for AT LEAST FIVE MINUTES. That is so the ENRICHER(CHOKE) cuts off the extra fuel when starting cold.
THEN:

Turn the Fuel Ratio Screw 1/4 COUNTER CLOCKWISE and wait 10 seconds or so to allow the motor to catch up with the new setting. LISTEN IF the IDLE GOES UP repeat the 1/4 turn COUNTER CLOCKWISE UNTIL on the LAST 1/4 turn it does noting OR the IDLE GOES DOWN-- THEN turn it CLOCKWISE 1/8 of a turn. That should be the highest and near best setting of the Fuel Ratio Screw.

NOW if on the very first turn COUNTER CLOCKWISE the IDLE GOES DOWN or does nothing
THEN DO the same thing BUT CLOCKWISE.
Alleyoop

[imnts2]

There is not a lot of extra amps in the battery so things have to be pretty near perfect to get it to fire quick. I don'w want to confuse things at this stage, but I would want to carefully check valve clearances the first chance I got. Just a little tight on the intake will sure mess up starting and fuel flow.
But you gotta get a steady spark.

Good luck.
Patience is a virtue on these sooots

lefty2

[sprocket]

Did you refuel? You may have over filled the gas tank and flooded the charcoal filter.. it won't run if this happens... when you cleaned the carb did you change the fuel filter and completely clean the gas tank?

imnts2 the battery only runs the starter motor it has nothing to do with the running of a scooter...