1971 - 1614 with an ongoing Vapor Locking problem (that I mainly attribute to ethanol gas & the gas tank being mounted directly above the engine & the sediment bowl being in direct line of fire with the hot air flow of the Head) .... Remember .... this is the PK model that the tank sits on top of the engine & has a thru hole for the spark plug.
This engine was completely overhauled/rebuilt in 1990. Bored .. 3 angle valve job .. yadda yadda ...not a "Paint Job Rebuild".
I have several other PK's .. but this is my slightly modified "Work Horse Tractor" & sometimes it gets Worked pretty hard. Heavy mowing .. Snow Plowing .. etc.
In hot weather .. after a couple hours of mowing high grass & weeds ... the typical signs of vapor lock ... sputtering & dying .. yank the choke on & it would run a little longer.
My entire dash & key switch area would get so hot you could hardly touch anything.
For some time now .. my plan has been to add a tin heat deflector from a later model PK. You know ... the angular box looking thing that directs the heat from the head down to the hog head area.
I snagged a deflector off of fleabay a few months ago & yesterday, started in to the project.
I knew there were going to be some modifications involved .. but no big deal. I knew the typical deflector mounting .. of 2 of the head bolts with studs sticking up was out of the question, because the studs & nuts had no clearance between the head & tank.
Flipped the hood up ... removed grill & gas tank .. then removed the existing head tin. Hmmm ... grass & funk plugging the air flow into the head fins. Now there's a sure fire heating problem ! This prompted me to remove ALL of the engine tin & clean it out good.
Tin back on .. proceed to figuring fitting of the deflector ... Wondering why the spark plug hole in the deflector wasn't jiving with the squareness of said deflector ... WOW ! WHAT'S THIS ! ? .... 2 cracks in the head .. radiating out from the spark plug. One crack with visible sign of combustion gas leakage ... DANG ! Yes ... dumbass me should have cleaned out the funk a long time ago !
Not so much of a problem .... went to the barn & grabbed another head off the shelf.
Hmm ... What's this ? The spark plug hole is in a different location.
Original head .. the plug is located between the intake & exhaust valves .... barn head , plug is located over the exhaust valve. Back to the barn to look at a spare/rebuild able K321 on the shelf. Plug over the exhaust valve. Looked at my other 2 PK's that are here (with deflector tin) .... plug over exhaust valve. That's why the deflector wasn't fitting correctly in relation to the spark plug. Ahhhh ... now , on with the project. New head installed ... original head tin modified for new plug location .... some deflector whacking with a zip-saw because the deflector now sits lower without the extended head bolts .. & it was down onto & hitting the hog head in the rear & the carb on the side & needed a large slot for the exhaust pipe & some more zipping for starter wire clearance. Some zipping & bending for coil mounting clearance .. pop-rivet the deflector to the original head tin .. & bingo .. done.
( Pop-rivets protruding into air flow may prove to be a bad idea ... if they start grabbing grass & funk in the fins. I may end up removing them & stitch a few welds to hold the new deflector to original head tin)
WHAO !!! WAIT !!! What about the dang new spark plug location ??? Is it going to fit in the gas tank Thru-Hole ???
Yes it did .... but just barely !!!
Just thought I would share this project & ask if anyone else has noticed that the spark plug location had changed on these engines ... assumedly .. AFTER / DURING the change to the "Long Hoods" ...
Or ... have I just not been very observant in my long history with PK's ???
I can take some Pictures if anyone is interested ...