Author Topic: 79 invader 340 problems  (Read 10374 times)

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fimbob793

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79 invader 340 problems
« on: October 17, 2014, 02:05:50 PM »
Hello. I have a 79 invader 340 in awesome shape all the way around. It has around 3000 miles on it. I bought it about 3 years ago and was running ok a little rough though. One day i was blasting across a lake and heard a pop and just died nvr could get it started again. Fast foreward to now i finally have time to work on it and found fuel was not getting to the carbs from fuel pump. So i replaced fuel pump cleaned carbs fresh fuel new plugs and all the lines were new wen i bought it. I am now getting fuel to carbs but it just wont fire up. Its close and it wants to but wont. Wen i pull it a mist of fuel blows out of carbs (on filter side). Im lost i dnt know what else to do. Any suggestions will help thanks.

gixxer6

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Re: 79 invader 340 problems
« Reply #1 on: October 17, 2014, 05:57:43 PM »
Do a compression test

mswyka

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Re: 79 invader 340 problems
« Reply #2 on: October 17, 2014, 05:58:10 PM »
Agreed, and do you have spark?
Intruders:  1978, 1979, 1981 Custom (Pink)
Invaders:   1980 440
Projects:    1981 Invader 440

fimbob793

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Re: 79 invader 340 problems
« Reply #3 on: October 18, 2014, 09:38:19 AM »
Yes i do have spark. I was thinking of doing a compresion test. It feels like theres good compresion but the only way to know is test it.

rminier

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Re: 79 invader 340 problems
« Reply #4 on: October 18, 2014, 11:04:37 AM »
Unfortunately, I have experienced that dreaded "Pop" sound when at full throttle, and it was always due to a siezed piston. If you don't have a compression gauge, you can always remove both spark plugs. The motor will pull over very easily with the plugs out. Leave the ignition off (obviously) and place your thumb firmly over one of the spark plug openings. Give the recoil a good pull and the compression should pop your thumb up. Check the other side, and if one side is noticeably less pressure, and won't even pop your thumb up, then you know....you have suffered the dreaded burn down. A gauge is certainly a better test. If you have good compression on both cylinders, continue to pursue the fuel system.
75 SnoJet Astro SS, 79 Kawasaki Invader 440 (two of them), 81 Scorpion Sidewinder, 82 Blizzard 9500, 83 Yamaha Vmax 540, 97 MXZ 670....and holding...for now.

fimbob793

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Re: 79 invader 340 problems
« Reply #5 on: October 18, 2014, 07:20:52 PM »
Ill give it a shot in about 20min and let you know results
results

fimbob793

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Re: 79 invader 340 problems
« Reply #6 on: October 18, 2014, 08:04:09 PM »
I put my thumb on holes. My thumb popped up on both cylinders. My gf suggested turning key all the way like i would be starting it with electric start and pull the cord so she held key and i pulled and it sounds like it wants to start even more then before. Could it be a electrical problem? Mite i add wen i first gotsled the headlight bulb would melt everytime i put one in. Does this trigger anything for anyone?

jimvw57

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Re: 79 invader 340 problems
« Reply #7 on: October 19, 2014, 12:38:31 AM »
Yup, sounds like a melted piston / cylinder. If you don't have at least 100 lbs of compression, it won't start or run right. If the mag side melted (most likely) then it will affect your fuel pump.

Lloyd (ljm)

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Re: 79 invader 340 problems
« Reply #8 on: October 19, 2014, 07:21:10 AM »


 I would use a gauge to check compression.  The pop you heard was likely a melted piston. I have heard that sound once too often.

77 SST
78 Intruder
79 340 Invader
80 440 Invader
80 Drifter (bought new)
80 LTD 4/6    X2

Several Deeres

Greg

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Re: 79 invader 340 problems
« Reply #9 on: October 19, 2014, 09:51:30 AM »
I have a 340 parts sled with a complete motor in if you need anything.....

fimbob793

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Re: 79 invader 340 problems
« Reply #10 on: October 19, 2014, 07:01:08 PM »
Well upon looking further the numbers on motor tell me its a 440 not a 340. The guy i bought it from told me it was a 340 but i guess he is a idiot

Interceptor398

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Re: 79 invader 340 problems
« Reply #11 on: October 20, 2014, 05:07:25 AM »
It was common if a 340 melted down to put 440 jugs on.

rminier

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Re: 79 invader 340 problems
« Reply #12 on: October 20, 2014, 12:02:53 PM »
Hmm, surprised that you found both cylinders popped your thumb up. Really expected you would find one side noticeably less than the other. Still, that popping sound you mentioned almost always means a seized piston. The only way to know for sure is to get a compression test gauge.
 There are 3 separate, tightly wound coils on the stator behind the flywheel. One is dedicated to only the lighting circuit. The other two coils work together with the CDI box to produce spark. The lighting coil typically puts out 18 to 20 Volts (same with most sleds, not just Kawasakis) and the voltage regulator regulates the voltage down to 13-13.5 Volts, which is normal for a 12 Volt system. Ordinarily when you start poppin' headlight bulbs, the voltage regulator has failed and will have to be replaced. If your sled initially popped some light bulbs and then started working OK, I can't explain what happened, unless the Voltage Regulator had a poor connection, and then "healed" itself. Your earlier problem with the bulbs should have absolutely no connection with the spark, however.
Try checking compression with a gauge, double check that you have a good spark on both plugs, and we will go from there.
75 SnoJet Astro SS, 79 Kawasaki Invader 440 (two of them), 81 Scorpion Sidewinder, 82 Blizzard 9500, 83 Yamaha Vmax 540, 97 MXZ 670....and holding...for now.

kawhead

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Re: 79 invader 340 problems
« Reply #13 on: October 20, 2014, 12:08:27 PM »
if you dont have a gauge, pull the exaust y pipe , look at the pistons.