Sometimes, after the bike has been ridden (sometimes only 15 minutes in warm or cold weather), when you stop and restart motor, it pops the 10 amp ignition fuse. It has been in the shop 3 times. My mechanic thinks he's solved the problem because the bike will start 40/50 times ok. He's checked the wiring,starter switch spring, replaced the fusebox, tried a 20 amp fuse (which also popped). I've been on long rides where it will start several times and then pop. It seems to work again after several hours and a new fuse. 1500 '99 nomad carb

Try using a lighter gear oil - some oils are thicker in really cold temps - like molasses while its warm drain it and use a lighter grade, - check the manual and go with a thinner type - ask local car parts store. sometimes the manual will give a type for colder weather. Good luck

take the air temp sensor off. and leave in warm house. till at your homes warm temp then go out and install the sensor.and start engine. if it starts this is your problem.

The choke function is not working on a cold engine.
1 clean throttle body and IAC motor air pathways.
2. Check for engine codes, you are looking for a code that relatws to the wngine temperature sensor.

just a common thing in cold weather, sometimes you have to ride about 5 miles with choke half out, till the engine warms up. try draining your carbys or cleaning them out, sounds like ti could be running abit lean and not getting enough fuel

You may just be catching the unit during normal defrost cycles. Next time, allow the unit some time to complete it's needed task. If you allow it 30-minutes, it should restart on it's own. The cycles are necessary to keep the unit working properly. The cycles will be more frequent as the weather warms. If you allow the unit 30-minutes and it does not restart on it's own, then there could be a problem. You might consult the owners manual for more details.

sounds like u might have a sticking valve. i do know that they have had alot of valve problems with this motor

Just a hunch, had this happen to a bike of mine years ago, could be the piston rings are gettting ready to go(wore down). What happens is when the quad is cold the rings expand tight into the cylinder walls allowing it to get full compression and run ok. When it heats up they shrink allowing the slightest amount of give which in turn will cause you problems similar to what your describing.

Don't rule out fuel pump. Had a 95 do the same, ran great when cool in morning then when it got hot in afternoon, it would quit. Wait 15-20 minutes & go again, sometimes got me home, other times a few more miles until it cooled down again. Luckily I had access to a fuel pressure gauge. Cool in morning had 49 psi, when it quit, 2 psi. Wait 20 minutes, 49 psi again. If you can drive it around until it starts to act up then run into a repair shop for fuel pressure test it will confirm it. If not, they may need it all day to monitor the fuel pressure & confirm it is pump. If your a gambler, change it & fuel filter. One thing I did get was trouble codes indicating a lean mixture, due to starving for fuel. Have you cycled your key to retrieve any codes yet?

Hey Tom, gonna try and help ya here...typical vapor lock/overheating is what your describing and i sure hear a lot of it w/harleys...are you using a very high grade synthetic oil , like castrol Syntec Actevo ? are you filling up w/ premium gasoline ?
make sure your timing is not too far advanced and don;'t let it idle too low...when you come to a stoplight stand up for a strech while letting your engine get air not blocked by your legs....all these things will help greatly......Good luck to you friend...Tim

no doubt this bike is running very lean at idle. Thats the way the EPA wants it. Im a harley mechanic and i used to work in a US dealer. all carb bikes at set up time had the carbs "readjusted". We drilled out the EPA plug and turned the idle air screw out and drilled out the pilot jet too. The bikes worked much better. we were at sea level too so the bikes were very lean from the factory. I can imagine that after the new legislation that came into force they are even leaner and require a full warm up to run properly. Warmed up means you put your hand on the motors head and its hot enought to have to jerk it away. this could take more than a couple minutes. and yes our "readjustment" was illegal. i advice you to do the same.