1978 390AMX - The Resurrection

[Colin Jay]

A few weeks ago I started the process of resurrecting my 1978 Husqvarna 390AMX.

 I originally bought the Auto on 5th July 1978. I bought it mainly for enduro use, and over the next couple of years rode it in a whole heap of enduros including two 4 Day enduros (DNF’d both). I also rode it in a few MX meetings in SA during the same 1978 – 1981 period.  After DNFíng the 1981 4 Day at Broken Hill (my home town), I fitted a SR500 Yamaha engine into the frame, and a YZ frontend and did a few club MX and enduro events with it.

The Husky bits were consigned to some boxes and have spent the best part of the last 30 years cluttering up the shelves in a variety of sheds.  After reading VMX  #42, I started to feel a bit guilty about having trashed an Auto Husky and had a hunt through the shed to see how much of it I could find.

And this is most of what I dug up.



After sorting through everything and finding that I still had all the important bits, including a brand new gearbox mainshaft and engagement gear in original packaging, I stripped the topend of the engine to find no rust or corrosion and everything in almost perfect condition.

So the decision was made to resurrect the old girl. I ordered a few gearbox bits and gaskets and some replacement mudguards and now have thing well and truly on the way. The plan is to just reassemble what I have with a minimal amount of “restoration” work. I am loathed to do a full restoration on her, because it would mean destroying the bikes history. This is one of quite a few “Part Markings” that have survived since the 1981 4 Day enduro, where I was No. 111.



CJ

[frostype400]

Very nice fox shocks and everything if not one of the best built bikes huskys have to be up top for best looking bikes.

[PEZBerq]

Do it! Do it! You wont DNF a 3 lap VMX race! Do you recall the reason for the DNF's - was it the tranny?

[Colin Jay]

I can't remember the reason for the ealier DNF's, I can remember breaking a final drive chain (masterlink) at an enduro at Wagga, but the 1981 4 Day DNF was definitly due to the gearbox problem, with the 1st gear/crankshaft clutch slipping. I made it to the 2nd last checkpoint on day 2, and when I tried to get underway to head back to the finish the tranny would just slip when there was any load. There was some degree of drive if I wasn't sitting on the bike, just walking along side, but as soon as I got on, it just wouldn't pull my weight. I had arranged to do a full gearbox swap in the work period at the start of day 3. Having organised to borrow the gearbox internals from a guy from the Cessnock MCC who also had a 390 Auto. I had practiced doing the change over and had it down to well under 10 minutes, which would have still left time to change the aircleaner element and do a few other bits of minor work on the bike. After the event, re-cutting/grooving the clutch shoes fixed the problem.

CJ

[LWC82PE]

Well here is a photo for your collection

[Colin Jay]

The TT500 engined Aberg special will be rebuilt eventually, I bought a 2nd hand '78 390CR frame a while back for it. All that I need to rebuild it is a seat, rear swingarm, time and money.

CJ

[shoey]

Hey CJ


It is recommended in the service manual that the first gear sprag bearing is regularly changed out.

It is also a service requirement to regroove the clutches regularly.

Apart from that type of first gear sprag bearing failure and the odd second and third gear spring breakage transmission failure should not be a problem.

Put it back together and you will soon remember how much fun thay are to ride.

[Pedro]

  Gday Col,
                  You are what vmx/vinduro is all about a bloke reliving his past  ; what a top post and some great real life pics the fire extinguisher certainly caught my eye  that looks like an old Metzler tyre sticker on the air box. So keep us posted on up dates of the resurrection champ.
                                                                                                            Cheers!
                                                                                                           Husky AU

[Colin Jay]

Shoey,
In the 3 to 4 years that I raced the auto, I had very few real problems with the gearbox. Problems that I did have were;
 I had a first gear clutch hub/spider crack,
 I also had the 8 screws that hold the clutch drum onto the mainshaft gear wheel shear fix by having the drum tack welded to the gear in addition to usinf the std screws,

I never had any of the springs break.  I used to regroove the clutch shoes after every MX meeting or enduro along with regular replacement of the first gear spag bearing, I also replace the other sprag bearings and the various gear shaft bushes as required, which wasn't that often. I also replaced a few mainshafts and engagment gears.

I can't recall ever having any problems with the gearbox at an actual MX event. But the gearbox just wasn't up to long / multi-day enduro events. In the '81 4 Day I changed the gearbox oil during the work period at the start of the 2nd, and tried to take it easy, but it just didn't make the distance. I supose that I can't really complain as I helped set and marked out most of the course for the '81 4 Day and was responcible for an awful lot of the shit hills that we had to ride over.

Husky AU,
Yes, that is an old Metzler sticker on the air box lid, and there it will stay. I was there to stop my boot rubbing on the actual airbox lid and was replaced regularly. The tyre on the 500 Yamaha wheel in the swigarm is one of the old Metzlers that I used to run, unfortunatly it has a split in it, so it won't be used, and I just fitted a set of Michelin AC10's onto the wheels yesterday.

CJ

CJ

[Colin Jay]

Well, some progress has been made. I have built-up the rolling chassis and fitted the engine into it. I still have to install the transmission, and I am waiting for my freindly local machinist to make up a couple of spacers that I cant find in the box of bits.



I have ordered some new guards etc and should get them in the mail soon, so hopefully it will be up and running in time for the SA Classic scramble championships on 24th Oct.

CJ

[Colin Jay]

IT LIVES!!

I got a chance to get back into the shed this afternoon, and put the gearbox back into the engine. Spent way more time trying to find the toolbox that contains the first gear clutch holding tool so I could tighten up the nut, but it all went back together quite easily. Suprisingly, after 30 years I hadn't forgotten how to put the thing back together, and only had to use the workshop manual to find the torque settings. As I couldn't find a husky throttle cable I had to modify an old Yamaha YZ one to fit the Magura throttle.

As I still don't have a servicable fuel tap for the tank, one is in the mail along with a some mudguards and an aircleaner element, I rigged up a dummy fuel tank, and after about a half dozen kicks, she burst into life, but the engine just wanted to rev it tits off. After shutting it down, I checked the carbie and found that I had made the inner for the throttle cable about 10mm too short, DOH! Back into the big box of bits and found a length of throttle cable inner, and remade the cable. She started up again after 2 kicks and settled down to a steady idle. Standing back listening to it idle, I couldn't beleive that after 30 years in pieces it would start and run so well. I am starting to think that I should have gotten my shit togther and done this years ago. I can't wait for tomorrow, I need to go into town and see my freindly machinist who is making up a spacer I need for the top triple clamp and pick up a parcel that is at the Post Office, which hopefully has the fuel tap and guards in it. All things going well I could get to ride the old girl for the first time in 30 odd years tomorrow arvo.

CJ

[oldmxracer]

What triple/fork/wheel setup are we looking at here?.?.?.

[Colin Jay]

The clamps and forks are 38mm Yamaha IT ones from about 1980. The front wheel is 1980 YZ465G (TLS brake). When originally built in 1981, I used a complete YZ465G front end that I bought new from my local Yamaha dealer. I eventually sold the forks on to a freind in the late '80's when the bike was dissassembles. When resurrected in 2000 for CD2, I fitted a 2nd hand set of IT forks that another freind had kicking around in his shed, unfortunalty the exact year/model is unkown to me.

To get the forks to fit the Husky frame I had to make a custom steering stem to suit the husky head bearings.

CJ

[oldmxracer]

To get the forks to fit the Husky frame I had to make a custom steering stem to suit the husky head bearings.

CJ

Thanks.

[Marc.com]

cool don't renovate a thing its like a time capsule, keep the period dirt even



love the blue carb on the HL

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