'78 OR390 shocks

[Tony Two Times]

I'm new to Sweden so have been scouring the web for info on my shocks but not coming up with much except that they appear on variosu Huskys of the same era. Anyone help on make model and their rebuildability?

[Tony Two Times]

Curnutt!!

Praise geebuz!! (and google).

At least I know what they are now. Still don;t know what the hell to do with them? 

[shelpi]

sorry to hijack, just interested how well the curnutt's work? never used them but have heard good reports

[Scootern29]

The Curnutt's you have work really well in cross country and desert type terrain. Motocross they work good if you get used to them. The faster you go the better they work. You really can't tell if they are working properly unless you are riding the bike. They are somewhat easily rebuildable if you can get seals down under, charging them with Nitrogen would be your problem without the special tool. Those shocks you have were set up for an average rider at the time of#180lbs. They are somewhat a delicate shock as you don't want to turn the rods with the shock extended as you can really screw up the internals. You need to compress the shock about !1/2 way to not damage them. I more than likely assembled those as I worked for Charles Curnutt from 1975-1982.

If you need help with them just ask. I am doing a service here in the states. Their are only 2 people that know about these more than me........Charles Curnutt and his son Charlie Jr.

[shelpi]

Gday Scootern29, do you sell the shocks and ship to Australia?

[Tony Two Times]

Holy smoke. Thanks mate. The internet for all it's cat memes really is an amazing thing sometimes.......

So many questions...........

1. Are they supposed to mount rod end up or down? I've seen both it seems.
2. Gassing - I am not an overly smart man and I don't doubt your advice but i can't see how they would be gassed? Were there also un-gassed versions?
3. I've read that ATF fluid was originally used but shock oil of say 10wt can be used as well?
4. How much ATF/oil?
5. From what I've read seals seem to be generic sizes which might make them available from a dedicated seal supplier?

But it sounds like the show stopper could be re-gassing. If the tool ain't available and its more complicated than my home garage engineering certificate enables me to build I might be looking for replacements unfortunately. 

T.

[shelpi]

rods up thats it for me

[Tony Two Times]

Found this at http://www.thumpertalk.com/topic/615414-rebuild-curnutt-gas-shocks/

Not sure how legit it is and still doesn't really explain how to get the gas in there................

•   Fill and bleed the dampers.
•   Screw down the seal head until seated, then back off one half of a turn.
•   With the damper shafts facing upward, push the rods until bottomed (the oil should come out of the threads.
•   Seat the seal heads.
•   Place the dampers in boiling water; the shaft should raise about 2 inches.
•   Loosen the seal heads and push the shafts down again.
•   Charge with 100 PSI nitrogen. The charge tool has an oring on the seal head and one on the body. Loosen the seal head and let the pressure equalize, then tighten.

Curiouser and curiouser..........

T.

[LWC82PE]

Modern Cycle Issue July 1975 has a Curnutt rebuild article.

[Tony Two Times]

Progress...........

[Tony Two Times]

Thanks LWC. Found that one on the web but it appears to be for a different shock. Assume 1975 version vs 1978 etc.

T.

[Tony Two Times]

Well in lieu of any other option for gassing I've shopped 'em out. Will report back once I get them back on the bike.

[Tony Two Times]

So some further research tells me the OR's may have been developed for desert racing in the US market and the Curnutts may have been stock items on them seeing as how they were a California based company.

But anyway to close the thread out, I ended up taking the shocks to Rad here in Brisbane. Gave them a full service, new seals, a little machining here and there to tidy up some rough edeges, and gassed them using a combination of modern technology and 17th century alchemy.

Gave them a workout on the weekend and they work great for 40 year old technology. Could go a little heavier on the springs given my weight but they'll do me just fine.

Most of all I'm happy to have avoided going for brand new shocks out of China. Understand why some poeple go that route but seemed to be important to use the original items.

T.