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Discussion Starter · #1 ·
I just traded my 2003 Ninja 250 for a 1997 Ninja 500 yesterday. The story goes like this:

I live in Fort Worth and I traded with a guy that lives in Austin, we met half way in Waco and from talking to him after the fact he has had no problems riding the bike back and forth to work nor did he have any issues riding the 100 miles from Austin to Waco. Now upon both of us arriving in Waco we switched bikes and rode throughout the town for a good 30 min both highway and surface streets at varying speeds and gears and I had no problems with the 500.

Well, after making the deal and starting back in our separate directions I got about 5 miles away heading north on I-35 and the 500 started surging, I was doing 70mph at about 5500 rpms, it would surge rpms would drop to 5000 and then the bike would die, I got it to the side of the highway waited a alittle bit then was able to restart and get back on my way, but this played out every 5 to 10+ miles for the 100 mile trip back home. Upon starting the 500 and getting back up to highway speeds I would have no issues and the 500 pulled strong, but once I settled in at 70 - 80 mph it would go for a little while then surge and die.

So this morning I decided to ride the bike into work but instead of taking the highway I took the back roads and the 500 never died or gave me any trouble at all on the 23 mile trip into work this morning. Now I obviously wasn't going as fast this morning as I only got her up to 45 mph for most of the trip but there was a stretch where I was doing 55 on the service road right by my office. This was with going up hill in 6th gear at 40 (low RPMs) trying to put a heavy load on the engine, down hill engine braking and just your normal ride into work. No issues.

The guy I traded bikes with said he would pay for any repairs that need to be done.

My best guess would be some sort of fuel delivery issue, but I wanted to see if anyone else had any ideas.
 

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How much gas was in the tank when this happened? Next time it happens, pull over, open the gas cap and see if air rushes in. Close the cap and see if it starts right away. This sounds like it might be a clogged or pinched tank vent causing vacuum to build up in the tank and preventing fuel flow until the vacuum goes away.
 

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Discussion Starter · #3 ·
How much gas was in the tank when this happened? Next time it happens, pull over, open the gas cap and see if air rushes in. Close the cap and see if it starts right away. This sounds like it might be a clogged or pinched tank vent causing vacuum to build up in the tank and preventing fuel flow until the vacuum goes away.
Tank was full of gas at the time.

Would this only happen at high speeds, as it did not happen this morning doing 40 - 50mph?

I am going to take it back out on the highway tomorrow morning since my drive home I'll never get going fast enough to test due to traffic.
 

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How much gas was in the tank when this happened? Next time it happens, pull over, open the gas cap and see if air rushes in. Close the cap and see if it starts right away. This sounds like it might be a clogged or pinched tank vent causing vacuum to build up in the tank and preventing fuel flow until the vacuum goes away.
My exact same thoughts. I'd be surprised if Ray didn't nail this one.
 

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Discussion Starter · #5 ·
I think on the 500 the tank is vented through the keyhole on the gas cap. Would just blowing some compressed air through it clear it out?
 
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