Author Topic: Strange RPM drop at 7k  (Read 2348 times)

Offline interfuse

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Strange RPM drop at 7k
« on: July 03, 2007, 10:37:41 AM »
My bike developed a strange problem yesterday. I've never had this one before. When cruising at 7k the bike would hicup and drop 1,000 - 2,000 rpm then kick back in. Almost like hitting the rev limiter. If I'm on the gas, no problems.

I'm stumped. I'm obviously going to have to start pulling stuff apart when I have a second. But does anyone have any idea's where to start? Does this sound like a blocked jet or a stuck slide? or does it sound like a bad coil? Water in the gas?
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline gsxr400 racer

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Strange RPM drop at 7k
« Reply #1 on: July 03, 2007, 05:18:57 PM »
lean surge maybe mess with fuel screws or jetting  :shock:
1988 gsxr 400 sp (sprint bike)
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Offline interfuse

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Strange RPM drop at 7k
« Reply #2 on: July 05, 2007, 12:08:26 AM »
Thank Jay. I'll focus my efforts there. The only thing that changed was a 10 degree celcius tempeture drop outside. It might have actually fixed itself now the temp has gone back up. I'll see.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline andrewsw

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Strange RPM drop at 7k
« Reply #3 on: July 06, 2007, 05:46:18 PM »
well, a temperature drop would make it run leaner...

A

Offline interfuse

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Strange RPM drop at 7k
« Reply #4 on: July 07, 2007, 12:26:35 AM »
Temp went up and its fixed. I dropped down the MJ when it got hot and the bike seemed to run better. But I must be a little lean a 7k and the temp drop sent it over the edge. Next time I take the carbs apart I'll go back up.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.