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Valve guide question

#1

J

JimmieG

I have a question about valve guides. Specifically in a Kawasaki 14HP motor in an older JD 245. How far should the valve guide extend into the exhaust port or the intake port or should you not really see much of them. I am not a mechanic so please don't be too rough on me..

Thanks for your help.
Jim


#2

B

bertsmobile1

About 1/2 to 2/3 .
In mowers both the exhaust & intakes sit at the same height
So if one sticks up higher from the head then it has shifted.


#3

J

JimmieG

So the valve guide should extend about 1/2 to 2/3 of an inch into the exhaust and intake ports? I have a couple of pictures that I can upload to look at.

Thanks
Jim


#4

B

bertsmobile1

So the valve guide should extend about 1/2 to 2/3 of an inch into the exhaust and intake ports? I have a couple of pictures that I can upload to look at.

Thanks
Jim

No 1/2 to 2/3 the diameter of the port.
The important thing is they are the same height off the head'
I doubt any one ever looks at the protrusion.
All I ever check is at full depression there is 0.010" or better between the coils of the spring and that the inlet & exhaust rockers look roughly parallel when piston is on the power stroke.
Trying to measure the protrusion is difficult.


#5

J

JimmieG

I understand. I appreciate your help because I am not much of a mechanic. I am trying to fix this mower for fun and so my in - laws can have their mower back again.

Thanks
Jim


#6

B

bertsmobile1

Well you might like to try telling the list exactly what you think is wrong.
What it was doing before you pulled it apart.
Why you are worried about the valve guide protrusion
What you have done to it so far.
No question is too silly to be asked but stupid is not asking.
Nothing you see hear ,see , smell or feel is too trivial to be mentioned.
We only know what you tell us I am 1/2 way round the world so all I know is what is on the screen.
DO you ave a manual, if so which one ?

Valve guides shift when the head gets way too ( stinking you can smell it ) hot.
Once they shift, pushrods bend or break.
They can also do this for other reasons like a valve sticking ( overheating ) or hydraulic lock ( leaking float valve or tipping the engine on side ) .


#7

J

JimmieG

This will either be a funny, sad or make you mad story for you. Long Story, but... The mower a John Deere 245 14HP Kawasaki motor was my father in laws and he had it at gentlemen's shop for repair. He was told he needed a new motor, but he is older and easily taken advantage of so I bought the mower from him with the intent of repairing and returning it to him. The symptoms were that it would not start and occasionally backfiring out the exhaust. I tracked it down and the mower had zero compression so I pulled the head. The exhaust valve guide had dropped just enough to keep the valve open so no compression. Remember I am a farm kid rather than a mechanic. My auto mechanic next door neighbor thought it a good idea to "tap" the valve back down, first bad idea. Tapping the valve caused the guide to break. I did not damage the valve because I really did tap it lightly. The valve guide is no longer available, from what I found from the on line parts store. I bought a used head off of EBay and installed it. The mower started, moved about 70 feet and died. We pushed it back into my shop checked the compression and once again had zero. I removed the 1st Ebay head and found that the exhaust valve was open. This time there was some corrosion around the valve stem making it difficult for it to return to normal position. I removed the exhaust valve cleaned it and swapped it with my original head exhaust valve because the stem was free of any corrosion. I lapped the valves and replaced the head and the mower ran perfectly for over an hour. I turned the mower off and restarted a few times without issue. Until the last time i turned it off when it seemed to backfire, spin reverse one or two revolutions and stop. It would not start even after a few hours to cool. I checked the compression and once again i had zero. I removed the head(getting good at this by now) and found the exhaust valve seat dislodged holding the valve open. The neighbor was convinced that the valve guides were dropped and it the wrong place, from his experience and I don't know. Some how he pushes the valve guides almost flush with the intake and exhaust ports, most of the guide is now up inside the valve cover. We also pushed the seat back into place and staked it. One thing to note is that I was running the engine with out all of it's shielding in place and may have over heated the head or that is what has been suggested to me why the valve seat came out. I have also been emailing the very helpful EBAy person that I purchased the head from. He read that there might be a compatibility issue if I swapped a USA head with a Japan head. He sent me a Japan head for me to use. So I have a USA head with the valve guides maybe out of place and a staked valve seat and a new used Japan head that looks ok, but the valve guides extend into the ports and I am getting tired of taking the head on and off. I wanted to find out from someone who knows more than me what the valve guide positions should be so maybe this is the last time i install the head. One last thing is this carburetor has an electric shutoff solenoid that screws into the center of the bowel holding the bowel in place..I think to prevent backfires. initially his mechanic told him that was the problem so he bought one($80). I don't think it works so I bought a metric bolt and a nut to temporarily bypass it and I did have the solenoid bypassed when the mower was running. I am thinking about using the 2nd EBay head rather than the one we have messed with.
Thanks
Jim


#8

J

JimmieG

I do not have a manual. The motor is a Kawasaki FC420V 14hp.

Jim


#9

B

bertsmobile1

No Jim,
We are not the CIA or FBI so no such things as too much information for your own good.
Sometimes I think this is the dentist forum because getting information is rather like pulling teeth.
So first problem solved
http://www.mymowerparts.com/pdf/Kawasaki-Service-and-Repair-Manuals/
Third manual down is yours so you now have a manual.

Yes running without the blower housing for more than 10 minutes or so will overheat the head and soften it so don't do it again.
Once softened it is effectively useless

If you had a backfire then a run on you will most likely have sheared the timing key in the flywheel so now the timing will be off and the engine will not start.
The cut off solenoid is spring loaded and rarely give any trouble unless the float bowl get full of water or gummy evaporated fuel.
IF it has 1 wire then it needs the body to be grounded to work and should retract when the ignition is turned on

Kawasaki sell valve guides #49002-2107 so the manual should have descriptions on installing them ( note I have not checked this ) or at least dimensions.
As for weather the USA & Japanese heads are different, no idea, I go to my first Kawasaki service school next month.
To check things more closely we need the spec number off the side of the engine.
Should be S?? ( ?=01 to 29 )
There is only 1 manual listed for the engine on both the USA & Aust web sites and we get both USA engines, installed in mowers & Japanese engines ( in boxes )

When you assemble the head again, put about 1mm thick plasticine across the top of the piston then turn the engine over a few times with the starter, remove the head and check for valve marks in the plasticine


#10

J

JimmieG

Thanks for the manual and your advice so far. Sounds like I should go with the 2nd EBay head that I just received. I will check the flywheel key, I have already had the flywheel off once. I tried to attach a picture of the engine tag, but that didn't seem to work so I have the information included in this email.
The Motor Code is FC420V - FS00
E/NO FC420VA93136

Thanks
Jim

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