Recieved the Roketa Gk-06 (specifically the model KTX-250WJF). I have a few questions. first of all, When I started it for the 1st time it kept dying. It took about 10 minutes or so to get the motor running. It was smooth with the exception of a hickup every now and again. It would bog down and die when given the gas. Should be a simple carb mixture adjustment. Have looked on the carb for the needle adjustment and cannot find it! Found the idle adjustment with no problem. I am going to replace the sparkplug in it as it is the stock plug provided by the factory. Is it normal for these motors to run like this until they are broken in?

After riding it for about 10 minutes or so, I pulled up to the garage and noticed the hoses were quite warm to the touch. The radiator was hot as well, but the fan had not kicked on. When should this fan kick on? Im assuming when it reaches a designated temp it will kick on.

The only other issus is the shifting control. There is no Neutral. I suspect that is just an adjustment to the linkage to correct that.

Thanks in advance for any advice you might be willing to pass on to a noobie to the world of buggies.

Make sure you change the oil. the oil roketa uses is crap. put good stuff in it. the oil it uses now is waxy and all the fluids are crap. make sure you break it in.

Sounds like it may be a bit lean to me. Now that you have a little time on it go ahead and change the fluids as roketa hater suggest. Don't try to go cheap with your oil as the good stuff will keep your motor running a long time between rebuilds. Change your coolant also and maybe use an additive to help keep the temp down. When the rings are seated and the motor is nicely broken in you'll be surprised how much smoother and cooler it runs. Right now everything is tight and the motor needs some break in time so all the moving parts can settle in.
913

the fans should kick in some were in between 170 or 210. then ounce they have cooled it back down to 170 or so they shut off.

Ok, Here is a list of the things I have done at this point. First thing I did after assembly is change all of the fluids. (engine oil, differential oil, and coolant)
For the engine oil I am using Valvoline 10-40 ATV oil
For the differential I am using 80w-90 synthetic blend by Valvoline.
For the coolant I have put in Prestone. Currrently running it in a 70/30 mix. (30 % coolant)

The owners manual is crap, I dont go by its reference at all. It stated that the differential took 10w-30. BS on that. It also calls for 10 hrs before changing in the breakin oil. Im doing it at 5 hrs.

I have not had the chance to test the fan as of yet. There is a lead on the blobk for a 1 pole temperaturs sensor. I am going to try to find a suitable guage for the buggy as I get real anal about a cool engine. I am also going replace the coolant with purple ice.

As of now there are only 2 problems remaining. I did adjust the shift linkage which has solved the shifting issue. I pulled the sparkplug, it appeared to be normal. Napa could not seem to crossreference the plug so that I could determine the appropriate plug to replace it with.

As far as the idle / dying issue, I have narrowed it down to one of two options at this point: It is either a coil problem or a carborator issue. I highly believe at this point it is as simple as an adjustment. On Saturday morning I did verify that the fuel filter was not clogged. It is fine. I also wanted to eliminate a clogged jet being the cause, So that same morning I pulled the carb and thouroughly went through it ensuring it was clean. I did not find the idle mixture adjustment screw where I sould have expected it to be. I believe it is on the underside of the carb towards the front of the engine. It was backed out a turn and a half. So at this point I am thinking that is the adjustment screw I have been looking for. Stupid engineer who decided to place that adjustment screw there. It appears that any adjustment will require removal of the carb to get to the screw.

Anyhow, Thats where Im at. As I am out of town this weekend, tomorrow morning I will be heading home and will be puttering with the idle adjustment tomorrow afternoon. Ill post the results of my findings once completed for others to reference in the future if the choose, however Im sure it has been posted in the past. Thankyou all for your advice and suggestions.

Ahhhhh, to be home puttering with the buggy........................
I could sure go for some of that this morning

Have been fiddleing with the needle for a few hours now. Have tried both leaning the mix and settting the air / fuel mixture to richer with no luck. While I have been able to get the engine to smooth out at idle, I am still having problems putting the engine under any load. The engine simply misses, backfires, or boggs down. I know it is a problem with the carborator . Does anyone know if there is a better carb / filter setup for the Roketa 250cc engine. Not to impressed with the Japanese one sold with the buggy. Would like to go with a K&N setup with a better carb if possible. Thanks in advance once again.

As far as I have been able to tell that screw is more for the mid range than for idle. I think it helps in the transition from pilot to main. When I turned mine in to get a smooth idle (about 1-1/2 turns out) the plug would go china white while driving steady state at 5000 and 7000rpm. I tried the same test w/ it 2 1/2 turns out and the plug was covered w/ soot. Still looking for a happy medium. I think that the wire coming off the temp sensor on the engine is for the electric choke. The wire on mine doesn't go anywhere, and teh fan is switched by a sensor in the radiator.

By adjusting the needle slightly I am able to get the engine to idle smoothly. But by doing so the midrange still has problems. This is where the problem is lying at this time. I cannot accelerate without the buggy falling flat on its face. It attempts to die when I attempt to accelerate. I have tried adjusting the carb in 1/16 turn increments both leaning it out and richening the mixture with the same results. I dont hear any vacuum leaks. Last night I took the fuel filter out of the entire picture and still am having the same issue. While I have been able to get the engine to idle smoothly, whenever I accelerate, the engine attempts to die or sputter. Im beginning to wonder if it could be plug / coil related. Thanks.

I chased the same problem for several days once thinking it was a carb problem. For me the problem was the two wires supplying power to the coil. The crimp connectors were bad. The buggy would idle, but when I tried to bring the rpm's up the engine would vibrate causing the bad crimp connectors to shake and loose connection. I ended up replacing all the electrical connectors on both my buggies.

Good Luck!
ElectronJunk

Thanks.
Ill look at that tonight
If thats the case they could always be soldered to the leads

Doesnt appear to be any loose connections. Continued the tinkering process and cannot get the carb to dial in. Seriously considering a replacement carborator for my buggy. Any suggestions on a replacement carb? Thanks.