NEW OLD 1991 TRX250X

Hello everyone, i have 2000 Polaris Trail Blazer 300 I’ve been stumped on for weeks. I’m having a lot of issues starting the quad. I cleaned the carb spotless because I thought it was a carb issue and bought a new fuel line because it wasn’t getting fuel. The carb gets fuel perfectly fine now but it won’t start. The spark plug I a little worn out but it’s good enough for just one start. The only time it does “start” is when I spray starter fluid into the carb. But it never stays on. It’ll start for a bout a second then just die out immediately even if you’re giving it some throttle and the choke is on. I have no clue what I should do. If you need more information, have questions, or have any slight idea what the issue would be and how I could resolve it. Please reply ASAP. Thank you.

I have a 1988 300 Honda FourTrax, All wheel drive.
My brother and I were fixing up this quad. We put a brand new battery and fuses in and it was running fine until we put the quad into reverse. As soon as it was put into reverse all of the electrical cut out and power wasn't making it to the head unit anymore and both of the brand new fuses popped. We figured there might have been a short from the starter or solenoids, but they are all working properly. At this point we don't know where to start looking for where the short could be. I'm just wondering if anybody has had the same issue or knows of similar issues that could cause these electrical shorts?

Buying a Baja 250 tomorrow for 600 bucks, needs nothing but a wheel bearing, i already know Baja is an off brand crappier. Manufacturer, but does anyone have any tips or knowledge of these bikes? 

OK ya'll.My son bought this thing and was told its a Kaw Bayou 300. Maybe. I cant find any numbers on it.The one tag I did find its so faded as to be unreadable. Its a long shot but maybe someone can help ID it. Thanks in advance.

I have a 2005 honda trx 300ex sportrax. I pulled the welded together crap of an exhaust that's on my quad I just picked up and the valve is ghost white. Do you guys no what exactly this means? Or do I just need to pull the head and rebuild it? I'm also looking for plastics and a cheaper stock exhaust if anyone has one. Thanks for your time.