Roketa 250GK-19 KTB-250W wont start!!
 

Hey all!! I just bought the above mentioned buggy for $200. Great deal if you ask me....anyhow it has spark but it will not start. It cranks just fine as well. It doesn't even act like it wants to start. Tried pushing the brake pedal while starting it too...nothing. It seems to have good compression as well. Valve adjustment? Timing off? Any help you guys can throw at me would greatly appreciated!!

pull the plug wire off of the spark plug and insert screw driver into plug wire and hold it 1/16" away from metal and crank it over look for spark {NEVER CRANK ENGINE WITH OUT HAVING A WAY TO CHECK SPARK} [ OR IT WILL BURN OUT CDI] if you don't get spark then order your self a AC CDI from BuyAtvsOnline.com they have the cheapest parts for good products I have bought 5 CDIs from them and they are perfect (I work on China made stuff along with just about anything else) Take care

Your CDI will not burn out by cranking the engine without plug or coil connected. How could you come to such a conclusion? If you look at the typical CDI schematic, you will see this is not possible.

* Firing the coil off-load should be avoided as it can cause cumulative damage by electrical breakdown. This is a quote from Mcaren Electronics, you may want to do some research before opening your mouth. Just because you can read a schematic, does not mean it warns you of any mishandling will cause problems. (case in point) I owned a 1400 cc Suzuki Intruder that the CDI was so powerful there were Warning potential DEATH if you were to mis handle the plug wires.
support@mclarenelectronics.com

In another application I would agree with you. However in these Chinese engines, the CDI's are much simpler and much less lethal. The theory is the same, but implementation is considerably different (cheaper).

I have cranked many of these engines over with plug wire disconnected and never had burned out the cdi.

have you made sure your getting gas to carb from tank
have you cleaned the carb make sure pilot jet and main jet not plugged off.
if it has set a while these thing will probably have to be done.

Valve Adjustment:
Remove the left crankcase cover (page 8-3).
Rotate the drive pulley counterclockwise and align the "T"
mark on the camshaft with the index mark on the cylinder head
cover to bring the piston to TDC Dead Center) on the
compression stroke.
Loosen the valve adjuster lock bolts, which are located on the
left side of the cylinder head.
Move the intake and exhaust adjusters outward (away from
each other fully until resistance is felt.
Then move them inward (toward each other) one graduation.
Tighten the lock bolts.
NOTE
• One graduation on the adjusters equals 0.10 mm (0.004
in), which is the specified value clearance.
Install the removed parts in the reverse order of removal.

You don't have to remove the right cover to check the timing. There is an access plug you remove on the right cover to line the flywheel mark up.

Yes. Tom is correct. There is an access port on the front cover. Since I always work alone I usually remove the front cover to check the timing.

Have not yet come across a CN or CF250 that did not have that acces plug on any brand, especially the Roketa's

My front cover does have an access port as well. Was covered with grease, grime so I didn't notice it.

On stator side cover is an oil line. In that line it T's off, right under that oil line T is an access plug to the flywheel timming mark. On the top side of plug threads in case is a squared slot cut into the threads, this is the mark for linning the flywheel mark to for tdc.

If sycarms says it, it is right 99.9999999% of the time. Tom is like an encyclopedia on these buggies.

Sycarms
 

I'll take another look at the cover when I get back to PA. May be covered with grease, dirt...etc. Sure wish you'd look at my thread. Really do need an answer before the next rebuild.

rebellinredneck
 

Okay rebellinredneck. I'll keep that in mind.

Ignition Timing
 

Have attached a file. Hope it worked. Sorry...Can't attach the file.
Remove the right rear timing cover (slotted screw) just under center oil pipe. Connect tachometer. Ignition timing is correct if index notch aligns with 'F' mark @ 1500rpms.