OK trying to get some feedback on my Gtr. Took a long ride a few wks back no issues at all other than nearly ran outta gas pulling back in driveway. Now I cannot get the buggy to start heard it backfire once thats it. Always was a little difficult to get it to first but after that the buggy would start very easily. I'm getting plenty of spark and I have cleaned the carb which wasn't really dirty at all. The one thing that does stand out is that the weather here has gotten drastically colder sense that last ride could this be an issue for the carter?? Or any other suggestions bc I really don't know where to go from here considering i a zero issues with buggy ever sense I got it basically and it has been maintained well please help.

Have you replaced the electric choke? Tried cranking with starting fluid?

There isn't a electric choke on the GTR.

dhaney, are you sure it's getting fuel to the carb? Check the fuel lines,filters, and petcock for clogs and the vacuum to the fuel pump.
If those are good, the fuel pump could be failing. You can try to start with starting fluid as Mike said. I've seen some people convert to a gravity fed fuel system on the GTR's instead replacing the pump. They install a tank on the rack above the engine and bypass the fuel pump.
But if it was me, I'd probably replace the pump.

It has gravity fed system. Starting fluid scares me a lil too much. If the buggy was on its last days i may consider it but. It just ran to good too strong. No smoke. Nothing and now this. I'm baffled. It was always hesitant to start initially sometimes u would have to remove the breather. But as the engine warmed up. It would start first try always. Sense ts getting plenty of fire and where I nearly ran it completely outta gas. I guess I could re do fuel line and fuel filter to theline. It has high octane gas in it. Thanks for suggestions. If I do give up and use the starter fluid which I really hate. Too. Pour directly into carb? Or spray into where air filter goes? Always heard keep starting fluid away from small engines and disels

Just a little spray of carburetor cleaner into the carburetor throat should allow the engine to fire.

Have you checked compression?

Ditto^^

OK. So. Ran my battery dead trying to start it over wkend. Broke out jumpers and literally while the car battery I was using to jump was going dead too. Got it to hit fir the first. By. Changing out my brand new plug wire and coil with my old barely holding on one. Withing I minutes I had it finally running again. But unfortunatky mystery is still not solved. Bc after I allowed to run for awhile and warm. And start like it's olself on 1st try again. O ditched back to my new plug wire and coil. And honestly could tell any difference. Until today. Would not start until I switched back to old. Tgen I let it warm up and switched backvto new and went for pretty decent ride. Ive concluded for the carter reslly does not like the cold and I really need a bigger carb put on. But very happy it's back to old self. Another weird deal. My fluids were low oil was slightly low and it does not smoke at all. Or is there trace of it anywhere. But for now just happy it's back running. Carter did get the dngine right on thus buggy it's about the only thing I would vouch for on the Gtr 250. Screams with the mods I've done.

I'm assuming there's a way to adjust the valves on a SYM 250. Yes?

I only heard of guys sending their gtrs off to be ported and polished. Need a 30mm carb or bigger is the one mod I haven't gotten too they everyone told me should be priority. Reason being it will have to a customer intake made to fit the new carb. Always wonder too?!? With my gravity fed fuel system what size fuel line should I be using. Def and surprisingly notice difference with the higher octane gas. And it's a totally different machine after its ran for about an hour. It's like it finally completely wakes up. Lol. Very solid engine surrounded by cheap cheap components including all the electrical system. Engine equivalent to a 400ex. W/0 the fun of a clutch. No exaggeration front end suspension is soft as butter too. Same as axles.