runs great when cold but after 3.5 miles misses

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pressop2006 · Sat May 26, 2007 6:10 am

89 ninja 600
have new plugs
new coils
some new vacuum lines
seafoam
premium gas
what am I missing?
should I spray some starter fluid on the boots while running to check for leaks? any ideas would be very appreciated

BuzZz · #2 Unread post by **BuzZz** » Sat May 26, 2007 6:25 pm

valves tight?
coil(s) breaking continuity as they heat up?
bad plug? new plugs are no guarantee
you're sure it's getting consistent fuel supply?
doubtful it's an airleak

pressop2006 · Sun May 27, 2007 1:42 pm

well Im not positive its getting fuel that was one of the theorys I had that maybe after it wormed up a fuel hose could be collapsing under the vaccum?

BuzZz · #4 Unread post by **BuzZz** » Sun May 27, 2007 2:38 pm

pressop2006 wrote:well Im not positive its getting fuel that was one of the theorys I had that maybe after it wormed up a fuel hose could be collapsing under the vaccum?

Unlikely the fuel line is collapsing, it's a gravity feed system to the carb.

It could be a vacuum problem, but the vacuum that acts on the petcock diaphram to allow the fuel to flow, not sucking the fuel line closed. Check the vacuum line from the carbs to the rear of the petcock.

You can try riding the bike on reserve and see if that stops it. If it does, it is probably the petcock diaphram or the vacuum line. If it doesn't help, your problem lies elsewhere.