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Inside the Kavan FK50 Four Stoke

TonyHallo

TonyHallo

640cc Uber Pimp
As most know I picked one up at a very reasonable price, it was mounted in the plexiglass display. The box had Version I on it, I understand the made three versions while in production. When I removed the engine from the stand to check to see if the timing gear was plastic or steel I found Version II written on the Hall sensor holder. I was pleased to find steel gears in the timing case. Apparently the idler gear in the middle is the one that could be plastic and it is equipped with needle bearings.
IMG_4757.jpeg

The timing cover has two hall sensors and it looks to be adjustable. There are two plugs on the cover, three wires go to the ignition and three wires go to a micro switch mounted to the carb. The switch appears to be wired to both the NO and NC contacts. Don't know if it is a kill or a timing adjust? There are two hall sensors mounted 180 degrees arat in the timing case cover and there are two magnets on the cam gear, sound like an old dual point distributor! Need to spend some time with a multimeter to figure out the wiring
IMG_4758.jpeg

I removed the oil pan and found no oil but looks good so far. Ordered what gaskets are available from MECOA.
IMG_4759.jpeg
 
TonyHallo

TonyHallo

640cc Uber Pimp
As I study the two hall sensors and how they are connected to the micro switch on the carb, I' leaning towards believing it retards the timing at idle. Hopefully I can determine the wiring embedded in the plastic and get it set at 28 degrees BTDC. There are very limited parts available, I bought valve cover gaskets, lower push rod tube seals, cam cover gaskets and an oil pan gasket. The cylinder to crankcase gaskets and head gaskets are not available, the Roto 85 uses an aluminum gaskets, I can make that on the lathe. I see engines listed for $2000 on eBay, don't know if they sell for that or not. I possible I hope to make the modification so they can be reversed.
 
dhal22

dhal22

GSN Sponsor Tier 1
I don’t remember how much I paid for mine, $900 I think. Plus the CH Ignitions conversion.
 
TonyHallo

TonyHallo

640cc Uber Pimp
Took a look at the heads again and realized there are no head gaskets, the cylinder and head are one piece, the black cylinder as seen above gives the impression of two pieces. The joint between the cylinders and crankcase are very close so I'm guessing it is sealed with crankcase sealant.
 
Snoopy1

Snoopy1

640cc Uber Pimp
So Tony what is your plan to reverse the rotation or just do a general cleanup and get it ready for a plane..
 
TonyHallo

TonyHallo

640cc Uber Pimp
The gaskets arrived today, don't get much for $60, must be the tariffs! Plan to do a full inspection and see what we see.

IMG_4767.jpeg
 
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