Hi everyone, my grandson's Coolster DX 3150-4 won't crank. I confirmed I am getting spark between the spark plug and "Coil" when turning over the engine.

I confirmed fuel is reaching the fuel inlet port on the carburetor. I pulled the carburetor and it looks clean on the inside. We sprayed some starter fluid in it and it acted like it wanted to start a couple of times with that but no go.

Any ideas what i need to check next? Thanks.

 

Oxymoron, "won't crank" literally means won't turn over.

However, Change the plug, just in case, if that doesn't cure it, try checking compression, engines with low compression will fire easier on starter fluid. If that is over 90psi there is probably still some dirt in the jets. Remove and clean them, and the holes they came out of, with compressed air.

 

Thanks. I will change the plug and check compression; Also, what is the electrical plug that plugs into the carburetor? Should there be electrical current through the plug when turning over the engine? Thanks again.

 

I don't know that model of bike. However electric chokes are usually at the top part of the carb and work off alternator AC, so no power until engine is running. Carb heaters are near the base of the carb and have power with ignition on.

 

Hi merryman, it's a Coolster DX 3150-4. I checked compression and it's over 90PSI. I changed the sparkplug and still no crank. I did pull the diaphragm and the plunger needed did have some sticky goop on it. I cleaned it but still no start. The carburetor bowl is attached with some kind of "non removal' studs so i could not get inside the bowl. I appreciate any other thoughts you may have. Thanks.

 

Either drill the heads off those screws (they will be "tamper proof screws") clean the bowl, jets and the holes they came from, out with compressed air, and refit using new metric screws, or buy a new carb. Put an in line filter on, as that "sticky goop" came from the tank, there will be more in it.

 

Ok, thanks;

 

Hi merryman, I just want to let you know that my son's ATV is now cranking fine. The problem was with the carb. Thanks for all your help.

 

You are welcome, and thanks for letting us know. So many of the people who ask for help never get back, telling us if my advice worked. Did you fix the existing carb, or go for a new one?

 

You are welcomed; Yes, I know I see that a lot of other forums, too. I went ahead and got a new one; It was only about $30 here:

https://www.vmcchineseparts.com/prod...150cc-scooters