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Discussion Starter · #1 ·
Hey guys...

I ruled out reeds, carbs, bellows....Sled wont turn more than 7k, and feels LOADED as soon as you blip the throttle. I have spark...could this be a bad crank seal?
 

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Tip to check for leaky crank seal.
Start the motor and spray carb cleaner in back of the primary clutch. If the engine increases RPM's you have a leaky seal. just don't go crazy spraying and spraying and spraying..... you know what I mean
 

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440man said:
Hey guys...

I ruled out reeds, carbs, bellows....Sled wont turn more than 7k, and feels LOADED as soon as you blip the throttle. I have spark...could this be a bad crank seal?
[snapback]296091[/snapback]​
if the crank seal is leaking there will be black greasy film on the back of the primary clutch. should only be dry belt dust!!
 

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You may also see iso-grease on the belt gaurd up near the primary clutch which is where I saw it on mine
 

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Discussion Starter · #5 ·
So if theres a leak, i will see evidence? Or will i need to spary some starting fluid?
 

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Doo Pilot
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440man,I would think your clutch side plug would be leaning out also !
if you had a bad crank seal.
Is it a fuel pump problem ? at high rpms not being able to keep up
clogged filter screen.
You did do a compression test

Rich
 

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Discussion Starter · #7 ·
compression is perfect...I dont think it would be a clogged filter screw because as soon as you blip the throttle she feels like PIG!
 

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Trust me. I read that tip in the newest snogoer about spraying the carb cleaner behind the primary.
 

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Don't know if the moon is not aligned right or what, but I've gotten about 6 calls from different 440 owners lately with the same symptons.
My guess is still the warm humid temps and carb ice is forming over the air screw causing the sled to run pig rich.
Everyone is coming up with same answers....reeds look good, good compression, leak down test good, good spark....runs like crap and drinks fuel like mad.
 

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The symptoms that I have seen on 440's with leaky seals are:

Boggy performance...even from initial ride away speeds.
Hanging idle....especially when HOT.
White plugs or burned piston tops.

Pig rich performance and 7500 MAX rpm. This happened on my '02. There was a small leak and it interferred with the way the engine was supposed to pull fuel. The negative pressure created within the cases is what pulls fuel from the pump. If there is a case leak then it could cause your problems.

Before you do anything, check if your primer is leaking and make sure your air/pilot circuits are clean.
 

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Went and looked at an 03 rev 800 last weekend with 2300 miles. Started ok, seemed to run ok, went into reverse ok, but when I pulled the clutch cover off there was greas on the inside rim by the primary and on the inside of the primary between the seal and plate. The plugs were blacer than black (I don't know how they weren't fouling). I told the guy his seal was leaking and he called me yesterday to tell me he spoke with a doo dealer and they said it was just belt dust. I told him belt dust isn't grease. So I feel for whoever buys that one. It's on ebay right now.
 
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