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Compression Release Kaw Fr651V

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#1 troyport OFFLINE  

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Posted April 11, 2014 - 11:34 AM

A few weeks back, I was asking questions about an electric clutch for this engine, the concern was the diameter of the output shaft.  Kawasaki clearly listed the diameter at 25Mm or .98".  Well, I bought the engine, the diameter of the shaft is absolutely 1".  So who knows?

Anyway, the engine looks brand new, but has been run.  I have a question on the compression release for this engine, the service manual does not talk about how it works..   I removed the spark plugs and turning the engine over by hand only one cyl will produce compression against my thumb.  Uh oh. If I apply power to the starter, both cyls will produce compression, hard to tell if they are the same.  Does anyone know if the compression release just completely makes one cyl drop out?  Or do I have a problem?  Thanks, Mike.

#2 EricFromPa ONLINE  



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Posted April 11, 2014 - 02:35 PM

You might want to check the valve clearances.It's showing a 2 piece single cam for that engine so it should hold both exhaust valves open a bit.


It's saying the valve lash is 0.004~0.006 on all 4 valves.



Here ya go It's on Section 2-10~12  pages 26,27 and 28.






That's a very good manual.It also has torque specs for every nut and bolt on your engine.

Edited by EricFromPa, April 11, 2014 - 02:40 PM.

#3 troyport OFFLINE  

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Posted April 11, 2014 - 03:18 PM

Thanks for the reply.  I have that manual already.  How can you tell from that manual that the spoiler will hold open both exhaust valves?  Please explain if possible.  I did find one other thing since my first post - the spark plug on the questionable cyl does not look like it has been firing correctly due to the ground electrode being bent down way too far.  The gap is only a .002" !! I don't believe it has been hit by the piston, no marks anywhere to suggest that.  In a short amount of time, could it have carboned-up the rings and they are a little stuck?  I didn't measure the clearance on the valves, but they do close all the way on both cyls since I can wiggle the rockers at TDC. I will measure, maybe the cyl that I am calling "good" is getting NO compression release due to too much clearance.   The engine turns over by hand smooth as silk, I can't think there is any internal damage. 

Edited by troyport, April 11, 2014 - 03:19 PM.

#4 JDBrian OFFLINE  


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Posted April 11, 2014 - 03:30 PM

You really need to talk to someone who has worked on one of those engines or who is familiar with how that CR works. Maybe a tech at your local John Deere dealer. JD has been using Kawi engines for a long time. With one plug nearly shorted it wouldn't have run very well.