I just got my 00 zrt800 back from getting a new top end put in it, when i first got it back it ran really good started on the second pull but now 30 miles later still on the first tank of mixed gas it is so hard to get started i have a sore back from pulling it over.It all started when i put new plugs in it BR9EYA's which i had in it before,and it fired right up and i let idle till it was warm and went to move it i got about five feet and it starts to back fire and loss of power then dies.Take the plugs out and there soaked so i dry them off put them back in fires up agian,anyways this happens 2 more times finally it starts working fine runing really well until i get a mile or so from home and same thing it dies,buy now i think it has to be bad plugs and i put the old ones back in and away it goes and ran good for the rest of the day.The next morning i go to start it, same damn thing all over again and when i parked it was running awesome,So i go and buy three more new plugs put them in and at first it runs like $hit then clears up and runs good for the rest of the afternoon,is it just the mixed gas doing this or is it a electrical problem any idea's would be great!!! Becuase iam getting sore pulling this thing over so much.......Thanks

does that have a throttle switch?, or , how much mixed gas is in your tank? my 96 zrt600, had carb. swicthes that did pretty much same thing till i by-passed them......if it idles fine till you hit throttle, then i'd start lookin at possible carb. safty swithes....

i`ve replaced the top end on my 96 twice (10000miles) and every time with the mix gas shes really hard on plugs but once you get throught that first tank my guess is it will clear right up. :)

You could try and shut the gas of when you are done riding it for the day. The floats in the carbs could be sticking and inturn putting gas in the crankcase causing the plugs to foule. It will also not always clean out once it is ideling. It may take 2 to 3 miles to burn the excess gas out of the case causing it to fowle plugs down the trail. Just an idea...

Similar discusson on another thread. An eazy test is to by-pass the wiring harness at the main 4 wire connector (close to the re-coil). If it starts easily in the morning you have a switch (key, kill or mag) problem. If not, I hope it's a plug fouling because of excess oil.

Thanks for the help everyone,Yes is does have the throttle switch my mechanic said to just unplug them but he also said i could just be water in the gas because its doing alot of backfiring aswell,I think i will get some gasline antifreeze and wait untill the first tank is gone and if the problem is still there start looking into those throttle switches.

All this sounds way too familiar...this is the same prob we had with my buddy's srx (no rebuild though, so no mixed gas)....SUPPOSEDLY the shop fixed it last month by installing a throttle bypass (or something like that). The hard starting and backfiring was unbelieveable with this thing. We got to ride about 30 miles the other night and it "seemed" to be better, but still a little backfiring, but definately better than before.

Hopefully you get yours straightened out...but you may not be able to know for sure 'til you get through that tank of premix.