Author Topic: A problem I noticed when syncing carbs  (Read 777 times)

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SySteMAtiC72

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A problem I noticed when syncing carbs
« on: March 20, 2018, 02:55:51 PM »
I have a few invaders. I've been riding one for years but it's beat up looking due to a crash. I had another one with an engine I rebuilt that was giving me a headache. So I pulled the engines and put the one from the beat up looking invader in the frame that is in solid condition. I will admit that I haven't changed crank seals in this engine. However, a couple of years ago I synced the carbs with no problems and have had no problem with cold starts. Typically I could get it to start on the second pull with no effort. Well after rebuilding the carbs and getting the engine back in the good frame, it gave me the same headache as the one that I rebuilt. Same problem as the rebuilt engine no start and backfires. I have a ton of br9 laying around from my former dirt bikes and sea doos that I still have. Swap plugs with the ones I used prior to pulling the engine. Bam, fires first full. So I probably pulled an engine that was fine over a bum spark plug...grr. So I get her warmed up to sync the carbs. After I hook up the homemade sync tool that I have, the clutch side pulls the fluid to the top. I've swapped carbs around and it's the same. If I pull the clutch side spark plug the engine will die but I pull the other there is no change in rpm. I've changed CDI, coil, and boots with no change.

Even though I'll hear it, I don't want to hear about crank seals, lol. If I have to pull an engine again I may just get rid of them because I have devoted to much time to these machines already. HELP!

mswyka

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Re: A problem I noticed when syncing carbs
« Reply #1 on: March 20, 2018, 05:33:56 PM »
I will begin by saying I am not an expert.  But we have been through many similar exasperating experiences with these sleds and with patience, hard work, and generous advice from this site we have overcome each and every obstacle. 

The plug exercise tells me it is running on only one cylinder.  Since the engine runs, the fuel pump is providing fuel to at least one cylinder.  Since the plugs are made to spark at the same time, they are likely both sparking and I am not assuming a spark issue.  My gut is that the carb on the dead cylinder is not pulling fuel.  Either there is some blockage in the pilot jet circuit or the needle/seat is stuck closed, or the floats are adjusted too high.
Intruders:  1978, 1979 X2, 1980, 1981 Custom
Invaders:  1979 340, 1980 440, 1980 440 TOC Custom
Projects:  1981 Invader 440, 1979 Invader 340, 1980 Invader 340, 1979 Intruder 440, 1982 Intruder 440, 1980 Drifter 340 F/C...

Checkmarks

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Re: A problem I noticed when syncing carbs
« Reply #2 on: January 03, 2019, 07:29:20 PM »
SySte,

Don't want to hear about crank seals?  How is it possible to begin to diagnose problems when the absolute canker sore  is the Kawasaki crank seals. In short, two hours and that very first problem can get ruled out.
I will try a shot at confirming what I likely already know.  On the poor running cylinder side try putting in a 45 pilot jet and running that one side with lots of extra fuel.  Run that poor running cylinder carburetor with the air mixture screw closed off.  Does it run better?  Let me know if the piston flows out the exhaust pipe.

Mswyka, can you still form up invader windshields?  How about an Ltd windshield?

Boomologist

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Re: A problem I noticed when syncing carbs
« Reply #3 on: January 05, 2019, 03:33:28 AM »
1. Try a NEW plug in the dead cylinder. Many times a plug will fire when laying on the engine but when under compression it won't fire.
2. Compression test?