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04 King Cat RPMs Falling Off. Help

nielnich

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Jan 10, 2010
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Lusk, Wy
I have a stock 04 King with a can. I've been having rpm problems since last year. I took it in at the end of the year for work. I got a new spider kit with MTX weights. Got it back and only rode a couple times. It shifts great and tachs out about 7300. But while climbing the rpms drop way off. 7000 or lower. So I thought this was a secondary spring problem. I was previously in the middle hole. I twisted the spring tighter 2 holes to the tightest setting. I rode it and still the same result. Tach drops way off and its like a big turd trying to climb. Also after doing some reading I wonder if its even lower than I thought (Tach may be off by 200 rpms?) I'm going to try a new belt next ride. Any other thoughts or suggestions??
 
G
Dec 24, 2008
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Check your helix and rollers for grooves. also if your secondary spring hasn't been replaced in the last 2 years swap it out. When you put your secondary 2 holes tighter did it raise your max rpm's?
 
Last edited:
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diggerdown

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Apr 25, 2004
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Deer Park Wi.
It's impossible to give much help without knowing the whole setup. Could be engine tuning or one or both clutches. Watcha got? If you're jetted right, I'd say you are throwing too much weight into the primary or the spring is too soft. You should be turning more R's to start with, 7300 would be alright on a long pull but not for a max number.
 

nielnich

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Jan 10, 2010
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I'm really not sure on my jetting. The primary has 71 gram SLP MTX wieghts and a gray spring (? probably stock). In the secondary, its a red and white spring - its probably old/weak. The rollers have been changed recentley. Should I try a new spring? Helix is a 55-53 and seems in good shape. Other suggestions??
 

JMCX

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Nov 26, 2007
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Sounds like you have the stock titanium spring in the primary. Someone has put a steel one in the secondary. Does it still have the Attack 20 track? If not just about every other track requires a change to a straight 51 helix to get the back-shift.
 
D

diggerdown

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Apr 25, 2004
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Deer Park Wi.
Don't know much about the MTX weights but if you are riding at much elevation the 71 are pretty heavy. R/W secondary is stock and will work fine as long as it is good. They sack out pretty fast and should be replaced every 500 to 800 miles. You need to check your jets, it sounds like you are running too rich plus a few clutch issues
 

nielnich

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Jan 10, 2010
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Lusk, Wy
Yes I'm running the Attack 20 in the hillclimb position. The spring in the secondary hasn't been replaced in at least 2 or 3 years. Maybe I will try that. I'll also check on my jets. Where should I be riding in Idaho around 7000 - 9000 ft?
 

JMCX

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SLP says to add 4g to what ever weight you were using when going to their MTX's because they are heel heavy.
 

Rixster

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Oct 20, 2005
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Springville, UT
SLP says to add 4g to what ever weight you were using when going to their MTX's because they are heel heavy.

good info, I know nothing about MTX weights. When my sles was doing the same thing, I discovered it was the SLP pipe. I changed back to stock and fixed the problem. My 900 just would not run with the slp single on it. No matter what clutching-jetting i tried!
 
G
Dec 24, 2008
135
63
28
I would start with the basics first. If you know the spring has not been replace in 2-3 years and your belt isn't new I would replace the spring and belt then ride it again and see how she does. If you do to much at once it's hard to tell what is making progress towards repair and what isn't my .02
good luck
 

nielnich

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Jan 10, 2010
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Lusk, Wy
Thanks for the help. Today I got me a new r/w spring for the secondary. I'll try that with a new belt this weekend. Also got a 51/49 helix that I may try next.
 

nielnich

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Jan 10, 2010
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Lusk, Wy
Rode Saturday with new r/w spring and a 51/49 helix. That fixed me right up. Thanks for all the help and good suggestions.
 
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