Bike starts to die when travelling above 80mph for a few min.?

Question

I've got an 85 kawasaki zl900 eliminator that runs perfectly fine for the most part. However, when travelling on the highway at over 80mph (5k-6k rpms) the engine starts to sputter as if i'm running out of gas (definitely plenty of gas). If I ease off the throttle a bit and bring it back down to 60 mph, it runs fine again. Is it sucking in too much air when at high speeds or something?

Answer 1

Before you spend loads of money having your carbs rebuilt or synchronized, replace your spark plugs. If you take them out and they are white, with ashey deposits, then your bike is running lean. I would replace the plugs and see what happens. This is by far the cheapest place to start, and a new set of plugs has never hurt a bike. Fuel starvation sounds skeptical because you said it would run fine for a few minutes at 5k-6k RPM's before it started to die. Try replacing your plugs. I would suggest an NGK plug because they are much better than other brands, especially Bosch. That's for both cars and bikes. Hope I helped...

Answer 2

Sounds like it is running out of gas. Check fuel filter or make proper adjustments to carburetor.

Answer 3

I just took my Piaggio BV250 to the shop for the same thing.  They are looking at it today actually.  I'm thinking either the fuel filter may get clogged when the throttle is open for a long time, or maybe the jets on the carb are getting clogged or something.  I didn't have the problem on surface streets, but only when on the freeway going about 70mph or so.  Like you said, when I slowed down it started working okay again.

I will post an update when I hear back from them later today.

Answer 4

If your bike has a fuel filter, check it.  Chances are, it may not.  If not, then it sounds like the float level in the carbs is set too low.

Answer 5

take it to the shop

Answer 6

Your motorbike is not designed to go extremely fast.  Make sure you follow the speed limit on the highways.  

Answer 7

Definitely a fuel blockage, could be a filter, could be the fuel valve, could be dirt in the carbs.  If injected, it could be the injector pump.  You need to investigate on that one.  Maybe you shouldn't go that fast except on the track, but it is a problem that needs to be addressed.

Answer 8

check your fuel filter

Answer 9

Weird, but if you want to go above the speed limit ( 55MPH in the US and 70MPH in the UK, you should be on the track )

Answer 10

my V65 magna did the same thing, the carb floats were a bit off once I adjusted them it stopped... Took me forever to get them right though, but now that they are all synchronized man it rips!

did you clean your own carbs recently?

Answer 11

I once has a similar problem and it turned out to be a pinched fuel line.

It let just enough gas through for about 45 mph but beyond that it lost power.  Check fuel filter and hoses.

Answer 12

Fuel Starvation, You may have a partially clogged Fuel filter if it has one or the Screen inside the tank may be partially clogged. If it isn't either of these, You may  need to rebuild the carbs.