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Discussion Starter · #22 ·
Wow nice pic. That explains a lot. Is that for all carbs or just Yamahas small engine? Anyways while I was soaking the pilot jet, I checked valve adjustment again. At TDC the intake valve had 2.5 mm of play. Spec says .06-.1 mm
 

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Administrator "Loose Nut" - From Houston, Texas
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Wow nice pic. That explains a lot. Is that for all carbs or just Yamahas small engine? Anyways while I was soaking the pilot jet, I checked valve adjustment again. At TDC the intake valve had 2.5 mm of play. Spec says .06-.1 mm
All CV carbs. A CV carburetor (Constant Velocity) incorporates a vacuum operated slide that varies the venturi size within the carburetor, thus maintaining a constant velocity. The slide also holds a needle that when lifted by the opening slide varies the amount of atomized fuel delivered.
 

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Discussion Starter · #25 ·
I swore I wasn't gonna mess with it anymore and just take to the shop next weekend but I can't help myself. I was messing with the air/fuel mixture screw on the bottom of the carb. It was 1 and 1/4 turns out before I started and it runs best at 1 and 1/2 out. Adjusting the screw doesn't change anything at idle, even closing it all the way. Shouldn't that kill the motor?
 

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Did you ever resolve this problem? I have 04 kodiak 400 sounds like exact same thing. Started with no spark Put a new coil changed nothing put a different CDI in that change nothing and finally ordered a pick up coil and now I got a good spark. Fires up in idles but rough same knocking noise they’re not ticks or loud text their knocks. As soon as you start giving it a little bit of throttle it’ll backfire and a hard stop and die usually with a loud knock. Seems like a carburetion fuel issue And took the carb apart many many times. I finally bought a brand new Mikuni carb and ruled out any carburetor issues. Did not change anything. When I put a timing light on it and I hear these knocks the timing light cuts out like it’s losing spark momentarily? Any help would be much appreciated I see a few other conversations like this but nobody ever gets to the bottom of it and reports back it seems.
 

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Pick up on line and cdi used oem from local atv parts junkyard
Has anybody else experienced this same issue. This kodiak has very little hrs. Owned by an old timer for around the yard. When I got it I forgot to mention that the needle and seat were leaking and gas ended up leaking into the engine. My next move I think will be to check again the pick up coil it’s a cheap knock off part from Amazon or eBay. And the magneto. ? Any thoughts.
 

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Discussion Starter · #30 ·
Very well could be the cheap pickup coil. I think the general consensus on here is to stay away from cheap online parts. I got a stator that came with a pickup coil from rmstator, it was less than 200. Are you sure the cdi you got was good?
 

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No I’m not sure.
Very well could be the cheap pickup coil. I think the general consensus on here is to stay away from cheap online parts. I got a stator that came with a pickup coil from rmstator, it was less than 200. Are you sure the cdi you got was good?
So when you got your new stater with a pick up coil and installed that that didn’t change anything either?
 

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Discussion Starter · #32 ·
Yeah no change after stator and pickup coil so I replaced cdi. That fixed no spark issue. Guess it could have been cdi all along, but I wasn't getting any voltage from pickup coil so I started there.
 
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