Kat flutters

[greencupbay]

My Kat flutters (almost like a rev limiter) at around 6-7.5k rpm if I try to accelerate quickly. If I just ease on the throttle, then it will redline O.K., but not like it should and not in 5th or 6th gear. I have adjusted the T.P.S. (somehow came misadjusted; thanks Psycho) adjusted my Idle adjustment screws by the Carb. bowls to 2.5 turns out, carbs are not jetted, float bowls are to spec, petcock has plenty of flow (I'd like to test this for sure if anyone knows how many gallons per minuet it's supposed to flow), new fuel filter, cleaned carbs, clean airbox, no hoses pinched/cracked/leaking? (if there are some tricky ones, let me know), new manifolds and manifold seals, oil is fine, using high ocatine gas, everything is tight (that I know of), diaphragms seem to be fine, and synced the carbs. (will do it again if told to). This use to be much much worse (not rideable) until the T.P.S. was adjusted. Does anyone else have this problem? Any fixes/tests I can run/ideas/questions? Thanks guys/gals.

[kevin2502000]

http://www.factorypro.com/tech/carbt...m_engines.html




2. Midrange (full throttle /5k-7k)

Step 1 (Best Main Jet) must be selected before starting step 2!

• • Select best needle clip position
• To get the best power at full throttle / 5k-7k rpm, adjust the needle height, after you have already selected the best main jet.
  • If the engine pulls better or is smoother at full throttle/5k-7k in a full throttle roll-on starting at <3k when cool but soft and/or rough when at full operating temperature, it is too rich in the midrange and the needle should be lowered.
  • If the engine pulls better when fully warmed up but still not great between 5k-7k, try raising the needle to richen 5k-7k.
  • If the engine pulls equally well between 5k-7k when cooler as compared to fully warmed up, the needle height is probably properly set.
    • Do not pay too much attention to the low-end richness when you are changing needle clip positions - you still need to be using the clip position that produces the best full throttle / 5k-7k power in conjunction with the main jets (Step 1) that produce the best power at high rpm. You will deal with the low-end / cruise next.

    
    

[greencupbay]

I don't have jetted carbs. I can't adjust the factory needle at all. This does seem to describe a portion of my problem because it runs better when cold, but worse when hot.

[kevin2502000]

Mine is completely stock too but following this diagram found out my float ht. was way off. Your sure the mains are stock, and you have a good clean OEM airfilter? ALmost sounds like you're running a K&N.

[greencupbay]

My mains are stock. It is an OEM, not K&N. What is that diagram that you are talking about?

[kevin2502000]

Click the link at the top of my other post.

[greencupbay]

That was great info. I am going to adjust the heights and see what it does. Ill post back. Thanks Kevin.

[kevin2502000]

Your welcome, I got it from Court93. It should be a sticky!

[Court93kat]

A sticky it should be.

[greencupbay]

Hey, I just wanted everyone to know that I did fix the fluttering with the help of this website. After adjusting my Throttle Positioning Sensor (TPS) which was causing my bike to not be rideable, after it WAS rideable it fluttered. It was indeed my floats. I had cleaned my carbs, adjusted the fuel idle screws (which were all messed up to 4,3,2.5,1.5 turns out with the brass cap still on), replaced my manifold and manifold seals, cleaned my air filter, tuned my carbs (about 7 times), adjusted my idle screw, and many, many more. The problem with the fluttering was the floats were messed up. When I cracked it open to check it, the floats were at 14,13,10,12 mm. All messed up! After adjusting it, I had my motorcycle back. If you are having the same problem where the bike flutters at high RPM's or when you punch the throttle, this could be your problem. A way a friend had me test to see if my floats were messed up was to roll the throttle (while riding it) to about 4-5K rpm (rpm's are subject to change depending on your carb adjustments, etc.), then punch it and if it just dies, your floats aren't getting enough gas. If you are able to gradually roll the throttle (while riding it) to the RPM's that it normally flutters, that is because the gas was gradually introduced and filled the carb bowls allowing it to have a sufficient amount of gas. Test your kat out if you are having this problem. It's a very quick and easy test. And a special thanks to Spraguepsycho1, Court93, and kevin2502000 for the info and their help. THANKS KATRIDERS!

Links:
Carburetor Site/ Info: http://www.factorypro.com/tech/carbt...m_engines.html

Throttle Positioning Site/ Info (TPS): http://katriders.com/wiki/index.php5...osition_Sensor

[Court93kat]

No problem at all man. Sharing information is what this site is all about!!