2000 YZF600r just dies out of nowhere

[Jdmluvr]

Hey guys, need some help. Just picked this bike recently and went to take it for a long ride today. On my way to Golden Gate, I turned onto 93 from hwy58, and the bike dies. Ron's hit 0 and I roll to a stop. Try to start it, no go. I check the obvious, fuses, wires, safety switches, still won't start. It cranks but that's all. So I call for a ride to go get my trailer. While I'm waiting I decided to see if I have spark, so I pull a plug off and stick my screwdriver in it, crank it, and what do you know, it starts on 3 cylinders. I jump on and start my way home. Just before I get home, it dies again. Same problem, won't start. Luckily my wife was behind me and we threw it on my trailer.

Seems to be dying after it gets hot. The bike temp is fine, I made sure of that both times. I don't see any other problems except for it dying. The first time I opened my gas tank to make sure it was venting correctly and it is. So, I'm guess maybe ignition module overheating???? Buy would that cause the rpms gauge to just show nothing?

[rybo]

My guess...

Bad ignition coils or CDI box

These fail (usually) just like you have described. No symptoms when cold and failure when they get hot.

The reason it shows RPM as zero is that the RPM is often taken off of the ignition system, not the crank. By knowing how many times the spark plugs fire, it's easy to compute RPM.

[Jdmluvr]

Awesome. Thanks for help. I'll replace one and try it, and go from there.

[TFOGGuys]

CDI or ignition pickup. You can check the pickup with an ohm meter, the cold value should be 189-231 ohms. I would expect it to be around 250 ohm hot. If you can check it immediately after the bike quits, it will be way outside that range, either shorted (near 0 ohms), or open (near infinite ohms). Unfortunately, the only way I know to check the CDI is to replace it with a known good unit. If it was a coil issue, it would probably only drop 2 cylinders(either 1 and 4, or 2 and 3) depending on which coil was failing.

[Aaron]

Is vapor-locking a problem on bikes?

I'm not sure but it's a problem I have with my Fiero, and does exactly what you described.

[NZ Darren]

I had an old yzf600r and it would just die out of the blue. Then start again in 10 min.
Only did it a few times and I never worked out why.

[Jdmluvr]

Yeah, seems like its vapor locking.... kinda. I tested everything with an ohm meter. It seems like everything checked out as per Jim's info. I coworker of mine works at coyote part time and he though it had something to do with some tabs on the floats that stick to the adjunct tower when the bike gets hot. So I pulled the cars and he did his thing and I put it back together. Rode the bike today all the way up golden gate over to Nederland, then back through coal creek. Was heading home on 120th and got to Colorado and boom, damn bike dies again. I waited about 20min, wouldn't start. Had the wife pick me up and we took our nephew home, came back, and it started... Hesitated really bad, it started. After about 10 seconds, it ran fine. My buddy from coyote is thinking maybe the fuel pump is starting to go bad. I guess I'll have to test it.

[Aaron]

Fuel pumps don't go bad generally over time, they die. One day they're fine, next they're dead.