Help Wanted ...Forked Forks

[PEZBerq]

On its maiden track outing at QVMX practice day last weekend the forks on the 87 510 Husky locked solid on the vinduro loop  Not a pleasant experience on the lose rocky tracks. Kind of ended the day for the 510 but fortunately the 390 auto was there to ride also so I went home knackered but happy from the first ride of the year. Aches and pains since disappeared 

The forking culprit was the conical floating non return valve on the damper rod of these Marzocchi design forks used by Husky in the late 80's. It had been pushed backwards into the valve housing and distorted to grab the damper rod locking up the fork solid. It was assembled as per the manual and parts book diagram with the cone facing up to the triples clamps. However I reckon this is backwards and it should be cone down to seal against the housing chamfered lip and not get distorted out of shape.

Does anyone know what the correct was to fit this conical valve is. See photos showing the two ways it can go.

Parts book way. Note pick up on damper rod.

What happened. Pushed backwards into housing and distorted to grab damper rod.


My alternative way


Valve housing



Appreciate the good oil so it doesn't happen again. Other fork leg is probably waiting to do it to me also!

[PEZBerq]

For anyone interested Andy from HVA Factory in UK confirmed the manual and parts book are wrong and the valve should be fitted with the rebound non return valve cone facing down. Hopefully this will stop the forks locking up in the future 

[Simo63]

For anyone interested Andy from HVA Factory in UK confirmed the manual and parts book are wrong and the valve should be fitted with the rebound non return valve cone facing down. Hopefully this will stop the forks locking up in the future 

Wow they admitted their manual (and parts book) is wrong 

I wonder if they've taken steps to rectify that problem or have they just let it go and not care about their loyal customers ?? 

[PEZBerq]

Perhaps there was a service bulletin? Husky issued heaps of them often with corrections to part numbers or other specs. Many are available on line from various sources but I don't know where to source a complete set for the 70's and 80's. Does anyone here know where to get a full set of service bulletins?

 BTW just in case you were unaware HVA Factory is a private business selling NOS and some repro and modified parts but is not affiliated to the actual Husqvarna factory - in Sweden, Italy or wherever the hell it is now - Austria?

[euro bikes]

Yes it's a bit sad the way the company has been sold and sold and sold dosen't help with confidence in a product.

[PEZBerq]

It's a valuable brand with many world championships so I am not too concerned. I dont think the new owner (MD and major shareholder of KTM) would buy it to close it down.  The sale price was not disclosed but it would have been substantial especially after the investment BMW made in R&D facilities, street bike range etc. GFC hurt Husky sales volume but its picking up again.

Wonder how long the new owner will stay with KTM - seems very odd. Can't see KTM needing to own Husqvarna so looks like a conflict of interest.

 Just wish they would start making parts for their 30 year old bikes again  ;Do

[80-85 husky]

I got a nice tip on setting up the early forks from Andy the other day but of no use to you for the Mazza's

[PEZBerq]

Pray tell John. I am sure my earlier forks could do with some tuning

[80-85 husky]

copied verbatim...
"Take a set of Evo sliders and mill off the disc lugs. Alloy weld up what is left of the holes from the disc lugs and machine back to make them disappear. Powder coat white and they look like the 83 / 84 bottoms. Take a set of damper rods from an 88 Enduro bike and fit them together with new seals and bushes. Fit some hva-factory Titanium bottom fork washers (they have an 'O' ring groove to seal the bottom and don't crack when you tighten the damper rod) Make sure the forks are compressed when you do up the damper rod - You will need a special socket to stop the damper rotating... Fill with 5w oil to 220mm air gap compressed with the spring out. Fit some springs and you are there. I will do a damper upgrade in the near future. One of the advantages of the evo fork is that they use a topping out spring - so no more 'clunk' when the top out washers are not under oil or not flat! The main advantage is that the damping is conducted at the bottom of the fork..."
There you have it - easy

[euro bikes]

Thanks for sharing that , so you use 88 fork springs when you change over?

[PEZBerq]

Spring size is the same. You just need to get the right spring rate for your weight and speed. I have cut my springs down a little to increase the effective rate and used a spacer to fill the gap.  Still plenty of travel left to avoid coil binding as original springs are very long and hence soft.