Tom,
You can e-mail me directly if you're having any problems constructing a leak down tester. I haven't had the need to adapt my leak down tester that I use on my Hodaka's for my KDX 200 yet but I'm sure that they will come a time.
For my Hodaka's I have to make adapters for the different exhaust configurations, i.e. for the 71 Super Rat I use a length of old two-ply bicycle tube and a hose clamp and cinch it down. Pressurizing the crankcase to 6psi causes it to bulge like a balloon. For the Super Combat and Combat Wombat's which use a completely different exhaust manifold, I use a piece of 1/8th" thick rubber gasket and COMPLETELY cover the exhust port, then install and bolt down the exhaust manifold, sealing the exhaust completely. Once I tried to start the engine, not realizing that I'd forgotten to remove this seal and had a difficult time figuring out why it sounded so muffled. <grin>
One the intake side, I buy PVC caps that have an OD diameter the same, or close to, the rubber intake manifold. If they're close, I use my bench grinder to grind them to the approximate OD as the ID of the rubber manifold. Then I buy a Schraeder valve used on big trucks from NTB (National Tire and Battery) and drill the PVC cap and install the air valve, and insure that it has an airtight fit. The air valve that I'm referring to has threads and a nut that you can use to cinch it down. I've used regular all rubber air valves before too but you have to closely match the valves size to the hole you're going to drill into the PVC cap so that you'll be assured of an airtight seal. Then I remove the innards of the air valve. To pressure test, seal up the exhaust, remove the carb, install your custom PVC cap where the carburetor was, cinch it down, attach your hand operated air pump to the PVC caps air valve and slowly pressurize to 6psi. Don't overpressurize the crankcase or you run the risk of blowing either one of your crank seals. Presurize to 6psi and see it it will hold it for at least 1 minute without dropping to 5psi. Spray soapy water around everything looking for bubbles. Where you see bubbles you've to an air leak. Often I've found up to 3 air leaks in an engine even when using new gaskets all the way around. I've always found that surprising, so I go back and use Yamabond in these areas or hi-temp sealant on the head or base gasket. I always try to get them to seal without using this since it makes rebuilding more difficult then next time around since you have to work harder to remove the gasket material since it's BONDED really well.
Phil Ketchum
Moderator, Hodaka Owners Group
http://groups.yahoo.com/group/Hodaka
'94 KDX 200 (new owner, no experience)