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Discussion Starter #1
Ok sorry for the length of this post, but here we go.

Bought a '99 ZX9R from a guy. Test road it and everything seemed fine except it was sluggish at low RPMs (thought it just needed new plugs[they had never been changed since this guy had it]). I buy it, ride it home, put it in the garage. Next day i try to fire it up and it just cranks. Sounds like the #4 cylindar is the only one evey trying to fire (and not reliabaly at that). So i figured that the plugs had finally fouled. Bought new plugs (ones recommened by service manual), put them in and crank it, still nothing, just cranks.

Thought maybe i was getting no fuel for some reason. Tested fuel pump, it works fine. Tested spark, they work fine also. I know it was getting air cause i had the trumpets opened to air. THe same #4 cylindar still seems to kinda half fire every once in a while while it is cranking.

This bike as it turns out has been running REALLY rich,so there is carbon in the cylindar, but still it should fire. I thought that I would get it started with some Ether, sprayed it in the trumpets, cranked it, now not even the #4 cylindar was firing. Ether evaporated and i put a little bit of fuel into the trumpets. Cranked it (this is the closest i ever got to starting) it sounded like a couple cylindars were burning but nothing started.

The valves were adjusted less than 3000 miles ago. However the previous owner thinks that perhaps the shop didn't do a very good job. I thought it was very odd that it ran, then just all of a sudden nothing the next day. Any help would be wonderful. Thanks.
 

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I'm guessing here... It could be a timing issue (firing at the wrong time) in which case its your crank angle sensor, or your spark plugs are hooked wrong (the wrong cylinders are firing), or it could be a valve issue, in which case you should compression test it.
 

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Discussion Starter #3
yea i plan on a compression test tonight. I will let you know.
 

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How long did the bike sit up before you bought it? Was it already warmed up when you test rode it? How old is the battery? How old is the gas in the tank?
Has the bike been modified?
 

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Discussion Starter #5
i am sure he had the bike running before i got to it. The gas was good. Only modification is a pipe which it has been jetted for. I knew the previous previous owner of this bike, when he had it it was perfect. pipe ran just fine and all.
 

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When you turn it over, does the exhaust start smelling like gas?
 

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Discussion Starter #7
Vash said:
When you turn it over, does the exhaust start smelling like gas?
yes, even backfired in the pipe a few times.
 

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Discussion Starter #9
Well she's running. We roll started it, at first it wasn't working to well. But after about 15 minutes we finally got it. Kept the RPMS up for a while to warm it up and then it idled fine. We then took the tank and airbox back off and hooked the fuel tank up with a long fuel hose. Then we steam cleaned the combustion chamber by pouring water into the carb trumpets at high RPMs. Seemed to work that pretty good. Still got to clean up the valves though. So what i'm gonna do is let it sit all day and night and see if it starts up under its own power tomorrow morning.
 

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i'm brent's brother.

the bike wouldn't start after sitting all night

*sigh*
 

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sounds like its flooding out, maybe a float stuck, or float adjustments, etc.

try holding throttle wide open while trying to start it, keep throttle wide open even if it fires, until it smooths out and revs up.
 
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