81 invader problems

[maxspeed6]

Hi, i have some trouble with my sled, a 440 invader 1981. I have it since 6 years now and he always run great. Since 1 month he start to have some running issues. The sled don't want to speed up past the middle of throttle, he doesnt want to rise in RPM. I already change carburator flanges, i have rebuilt my primary clutch, diassembly and cleaned my driven clutch. The compression is 150 each. The sled start fine, idle fine cold and hot, it run great on acceleration and take all the power still i reach some speed. The spark plug is brown that indicate to me that i don't run lean.
What is your feeling with that?

[maxspeed6]

When i have rebuilt my primary, the sled run great for 3-4 hours and the problems come back

[mswyka]

Two thoughts that you should look at in addition to the clutching:

1:  Brake could be dragging
2:  Track too tight

Also, we have never bought a new belt - we have so many parts sleds that we have just used old belts and when one goes bad, we grab a new one from the stack.  We have also had problems when we grab one that may have either shrunk or might not have been the correct Kawasaki belt.  So sometimes we have to swap in a different belt to keep everything spinning properly.

[maxspeed6]

How did you know when the belt goes bad ? I have the correct width but maybe worn anyway ?

[mswyka]

How did you know when the belt goes bad ? I have the correct width but maybe worn anyway ?

They are bad when there are threads flying out, lugs/cogs/teeth missing, or it doesn't sit correctly between the shivs

[kawhead]

when everything is warmed up and you can pull the belt backwards thru the sheeves the belt is too long/narrow[engine off]  i'd check my carb o rings, they could be mushy

[maxspeed6]

After another test ride , i have recheked my spark plug and i have a mid brown color on one side and a carbon fouled plug on the other. Seems to be over rich. I dscovered that i tie wraped my enrichiner cable since a month before rebuild of my primary clutch. Maybe the cable doesnt return to her place and make me run rich! I will buy some new plug today and test this tonight. I will be happy if that solves my problems

[maxspeed6]

The enrichener cable is not my problem. I put new caps and plug and after a 30 min ride , the left side is already black. The other side seem to be good with a brown color.
I can solve it with the air screw or i need to remove and clean ??

And to finish, my limiter ( strap ) on my rear suspension arm is broken. Do you know if it's stilk available? If not what i can do ?

[mswyka]

Kawhead had suggested checking the rubber "O" ring at the bottom of the needle jet.  Did you check this?

Also, after a 30 minute ride is the sled performing well or still running poorly?

[maxspeed6]

No, i missed that. I will check that. Its the oring on the needle jet seat ,right ?

And after my ride, no, the sled still bog at hi-speed WOT

[mswyka]

The o ring seals between the bottom of the needle jet and the bowl of the carb. The main jet feeds through thr bottom of the bowl into the bottom of the needle jet through this connection. If the o ring leaks the main jet is no longer limiting the fuel and the engine runs rich.

[maxspeed6]

I removed my carbs and my oring in my rich cylinder carb is not sealing perfectly. I will change that and test the sled. Itis normal that the float handle adjustement is not the same in 2 carb?  And i have a throttle cable broken. I have at least 3-4 little wire still there on the cable.

[mswyka]

There is a proceedure in the manual for adjusting the needle valve shut off.  The two carbs should be fairly close.

If the throttle cable is frayed it would be best to get a new one.

[maxspeed6]

My sled finaly run much better. He don't bog anymore and power at WOT is back.

For the cable, he come in a whole piece or i can buy just the carb section before the diviser?

[mswyka]

My guess is that while you might be able to find just the piece from the throttle lever to the junction block, it would probably be easier to get a whole cable.  I believe Dennis Kirk has them for Invader.  Also, check with JDMatt, he may have them also.