Recent Find - One Owner 1981 Wr 430

Late 2021 I was privileged to be handed the torch as custodian of this one-owner 1981 Husqvarna WR430. I got it from the original owner who bought it new in 1981. Very well looked after, and hasn't worked hard. Rims still bright gold. Best part is that when it was new he removed many parts and put them in a box, such as the lever covers, sprocket cover, chain guard, plastic sidecovers, headlight, speedometer etc, and also replaced the rear mudguard/tail light with an MX style one, fitted a camel tank and Renthal bars. Engine guard and some other bits are Preston Petty from 1981. I have the original handlebars. The sidecovers look fresh off the production line, the Aluminium tank doesnt look like it has ever seen fuel, and the speedometer is on 90 Kms. The trip meter matches the odomoter - both on 90 Km. Original seatcover with Husqvarna script. Original pipe and silencer. Unfortunately the headlight number board which is white as snow and looks fresh off the production line, got snapped at some stage during storage. Got a leather rear fender tool bag with some original Husky tools.

It hasnt run in a good few years, so I have the carb off for cleaning. And I expect I should do a leakdown test as I dont want to damage that piston or barrel which I expect are in very strong shape.

How do I do the leakdown test?
I've watched the few '81 WR430 videos on Youtube, and can't wait to hear it run!

Any other '81/'82 WR430 owners please make contact. I love to see pictures of them.
I plan to fit all the original parts for a photo shoot and a few light rides, but then will take all those parts off again, so that I can ride and enjoy the bike. I do ride on the Vintage enduro and MX circuit, but will save this one for light use (and no rocks!).

Thats a nice find. Of the couple dozen Huskys that have pasts through my garage over 50 years I regrettably skipped the early 80's due to a busy life and went from the late 70's to late 80's. All of them were great rides.

Leak down test is definitely a must. I can say with confidence that your old 430 will have a leaking left crank seal. How bad the leak is can only be determined by testing all other leak sources first.

How I do it.

1. I remove the exhaust, carb, and ignition cover and ignition.
2. The pressure source needs to have a low pressure gauge with graduations no higher than about 10psi in order to be able to read the graduations easily, and a valve to turn off the flow once 6psi has been reached. I use an old hand pump garden sprayer, its cheap portable and doesn't build up so much CFM that I risk over pressurizing.
3. Plug the exhaust and intake. I've used plumbing expansion plugs in the manifolds and on a few occasions have fabricated 6mm thick plates with gaskets and sealant to cover the ports although this technique doesn't allow for testing the manifold to cylinder connections.
4. Connect the source of air pressure to the top end via the spark plug hole. Make sure the trans is in neutral so the piston can free wheel to the bottom of the stroke, then turn on the air until 6psi is reached.
5. As the gauge drops in pressure as it most likely will, spray water that has a few drops of dish soap around the base of the head where it meets the cylinder, and at the exhaust and intake connections, and at the cylinder base, and at the right crank seal. Look for foam or bubbles.

If the pressure drops below 5psi within 5 minutes after fixing all the leaks then the left crank seal or center case gasket is leaking, most of the time it is the seal but you'll have to split the cases to replace it so the center case gasket gets replaced anyways.
Once you've finished the testing report your results and I'll share how I seal them. I can promise you that you'll get a lot more help from others by posting low resolution pictures of the bubbling-foaming sources. Good luck!

Thanks very much, that is a great help. Bit of prep and time needed there. I'll post updates, thanks

Some additional pictures