2001 Yamaha Warrior Stalling out when warmed up and wont start back up until cool?

Hello fellow instructable users!

I have a 2001 Yamaha Warrior (as seen in profile picture). When ever I go out to ride the four wheeler has a hard time starting. I have to use a lot of starter fluid and patients (about five minutes worth). Once I finally get going it seems after about five minutes, about the time it takes for the machine to really warm up, it stalls out and I can get one more start out of it and then it stalls shortly after. Another important point is the fact that the spark plug is unusually dry. After the bike cools down I can get it to start again and ride for about a whopping five minutes and then its dead until it cools down again. The situation is that something is getting hot and changing, causing the bike to stall. The bike has a brand new battery, ignition coil, and the starter is in very good condition. What should I check for next?

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Aplonis6 years ago
I had this exact problem on a 1997 Yamaha RSTD. For me it was a faulty ignition switch, mounted right behind the radiator. On the 96 it had been mounted further aft but for 97 the moved it forward. After a couple of years the heat from being between the radiator and the left, front cylinder degraded some plastic part in the key cylinder, making the ignition iffy.



Thus it behaved very like vapor lock, but was more variable. I found that jiggling the ignition switch if it cut out at speed would get it going again for an hour or longer...until the next cut-out. This was discovered while on vacation in the Great Smokey Mtns, of course. Rather inconvenient. But Yamaha fixed under warranty as soon as I got it home. Since then, no problems at all. I still have that same bike as of this writing in 2011.
Kiteman7 years ago
Does it have a choke?

Is it still running at its cold mixture when hot?
That's my thought; if it runs when cold (which needs less air) then stalls when hot (needs more air) -- the air filter might be cloged, or the carb may need adjustment.
mikeasaurus7 years ago
There might be a temperature gauge that is tripped when the engine runs too hot and automatically triggers the safety shut-off.
lemonie7 years ago
Check your fuel-supply (inc filter), check your air-filter, and then think about cleaning your carb'.

L