Author Topic: 78 Invader 440 is boggy  (Read 2345 times)

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DaveP

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78 Invader 440 is boggy
« on: February 13, 2021, 04:16:40 PM »
So I just purchased a 78 Invader 440 and took it out for the first time.  Its in great shape and starts in 2 pulls.  Owner said the moter had been rebuilt years ago.  I was disappointed in the sluggish takeoff and when it did get going it seemed to stop pulling around 40mph.  Could it be the carb jetting and if so doe anyone have the jet sizes?  Could it be the clutch spring?  I can tell theres a yellow spring in it.  My kid was blowing me outta the water with a cyclone 340 so i need yo fix this issue.  Any opinions and help would be greatly appreciated.

mswyka

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Re: 78 Invader 440 is boggy
« Reply #1 on: February 14, 2021, 10:14:38 AM »
The Invader is an amazing sled.  Clearly the performance you are seeing is not what this sled is fully capable of.

There is no way to fully know the condition of the engine.  The fix, while simple, may take a while to sort out from all of the many factors that can affect sled performance.

From what you have said I am suspicious of two things, the carbs and the clutching. 

The sluggishness suggests to me the  carbs.  And the topping out at 40 suggests clutching.

I would suggest a thorough carb cleaning and new jets.  And, I am not a wizard with clutching, there are others here who can give  you better advice on clutching, but recently we found that a number of our sleds, because they sit so much were not allowing the secondaries to open.  Just polishing the jackshaft on one Intruder  found us an additional  10 mph!  And I think that there is a little more that she can do if I work at it.

So at the end of the day you probably have a number of little issues that are adding up to the observed performance.  The really good thing is that she runs and you  know that you have spark.

Also, I am assuming that you are using fresh fuel.  They never run right with old fuel.
Intruders:  1978, 1979, 1981 Custom (Pink)
Invaders:   1980 440
Projects:    1981 Invader 440

DaveP

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Re: 78 Invader 440 is boggy
« Reply #2 on: February 14, 2021, 03:49:09 PM »
Thank you for the reply.  I do have good spark and put fresh rec gas with klotz oil as the sleds previous owner got rid of the oil injection.  I plan on cleaning the carbs this week and am hoping thats the issue.  I have read some clutch posts that people are using the black spring to obtain higher take off rpms, like in the 4100 range.  Any idea what the best jet numbers to use.
Thanks for all the help as im new to the kawasaki sleds.

mswyka

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Re: 78 Invader 440 is boggy
« Reply #3 on: February 14, 2021, 06:56:50 PM »
Jets on the Invader are 30 pilot, 150 main, 120 powerjet

There have also been a rash of primer failures lately.  Check the primer operation also.  Problems that develop can be leaking air into the fuel system and/or leaking fuel into the carbs.
Intruders:  1978, 1979, 1981 Custom (Pink)
Invaders:   1980 440
Projects:    1981 Invader 440

DaveP

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Re: 78 Invader 440 is boggy
« Reply #4 on: February 15, 2021, 05:01:04 AM »
Thanks for the info on the jets.  Hopefully a deep cleaning is all thats needed.

DaveP

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Re: 78 Invader 440 is boggy
« Reply #5 on: February 21, 2021, 07:29:28 PM »
Msywka..fyi..i pulled both carbs off and the jets were pretty dirty and one of the carbs the powerjet was broken off.  I was able to fix the powerjet and clean up everything.  I put them together and it was still boggy.  I pulled them again and replaced both tiny O rings in the carbs.  Runs great and is a fast sled.  My problem is now that my brake rotor seems to be warped becaus my lucks are sparking a bit.  Any ideas or advice on replacing the rotor.  I know the chaincase has to come off.  It just looks like a pain to change the rotor, if i can find one. 
Thanks again for the help.
Dave

mswyka

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Re: 78 Invader 440 is boggy
« Reply #6 on: February 22, 2021, 06:39:08 AM »
Msywka..fyi..i pulled both carbs off and the jets were pretty dirty and one of the carbs the powerjet was broken off.  I was able to fix the powerjet and clean up everything.  I put them together and it was still boggy.  I pulled them again and replaced both tiny O rings in the carbs.  Runs great and is a fast sled.  My problem is now that my brake rotor seems to be warped becaus my lucks are sparking a bit.  Any ideas or advice on replacing the rotor.  I know the chaincase has to come off.  It just looks like a pain to change the rotor, if i can find one. 
Thanks again for the help.
Dave

Glad to hear that you found the problem.  Those little "O" rings can be fussy.

Changing the brake rotor is not as bad as it seems once getting past the realization that "the long way is the short way."  The chain case cover will need to come off and the secondary will need to come off.  After that, if the brake rotor will slide on the shaft, it is pretty easy.  If you want I can look to see if we have a spare rotor that spins true.
Intruders:  1978, 1979, 1981 Custom (Pink)
Invaders:   1980 440
Projects:    1981 Invader 440

Interceptor398

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Re: 78 Invader 440 is boggy
« Reply #7 on: February 22, 2021, 05:56:28 PM »
My 81 Invader could use a fresh brake rotor.  The bore get warn a bit and they can bounce around a bit.  The rotor and pucks are kind like "wear parts".

DaveP

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Re: 78 Invader 440 is boggy
« Reply #8 on: February 25, 2021, 12:01:34 PM »
I bought some new pucks and will see how well the rotor spins with them.  I did find a rotor on ebay and will try that if the wobble persists.
Thanks again!