motoswm

Dont think your 1980 would have been anything other than a black frame with yellow plastics and tank. However.....there were a batch of 1981 models sold in the UK with odd colours. The factory held an end of season party to celebrate Gilles Burgats World Championship to which all the UK dealers were invited. On display were the trials, enduro and mx models but in various combinations of plastic and frame colours which they got the dealers to vote on. They ended up by choosing the blue frame/yellow plastic option for the trials bikes. There was an SWM dealer in Yeovil called John Gillard who ran Stoford Motorcycles who did a deal with the factory to sell off all the display bikes. I have a set of blue plastics from one of these bikes which had a silver frame, and have seen another with red frame, genuine red seat and yellow plastics.

Hypothetical question. If Sammy Millers original prototype 4 speed Bultaco 669NHO was to come up for sale, what's it worth ?

Yes its the bike that was mentioned in CDB, although it doesn't get used much as I am mainly riding enduros on SWM's this season. The Aprilia case is a big benefit, apart from the action which is loads better than the standard set up, the case is a lot slimmer, its 2 piece - so you can change the plates without removing the kickstart and you dont get the "kickstart punching a hole in the cover" problem. Glad you got your clutch sorted.

You have to replace the counterweight, which is easy enough as all the Rotax enduro motors use the correct nut. For the "eagle eyed" amongst you.........its also possible to use a kicksart with this case I broke this one before I rode the first section and had to bump start it all day. Martin

Or go the Aprilia route

Did you adjust the screw on the clutch arm when you swapped the cases ? If not unscrew it a quarter turn at a time (take up the slack on the cable) and see if that cures it. If not it sounds like clutch springs. I rebuilt an Aprilia TX300 recently that had exactly the same problem. This one was running on 4 clutch springs and was super light in the first 3 gears and slipped like hell in top. I stuck another 2 springs in and it cured it.

I have a TX300 for a motor tune up at the moment. The Rotax motor is nearly the same as the SWM unit, although the clutch is fitted with the later actuating arm that runs on the larger ball bearings. Clutch action with this is very light, its running on 4 springs and is probably better than the later TXR clutch version that I have fitted to my SWM. Carb is a standard Dellorto PHBH26BS, jetting and slide are different to SWM, although I'm not sure if this is because someone has been messing about with it.

You could be right with the mix and match seat. The long seat didn't use straps but had a rear fixing bolt that went through the Mudguard. Yes, I have the lower pins on my Gusnaco, they used what looked like a long O ring to secure the back of the seat.

The last ones were welded by a guy at Westland Helicopters, I will try and find out what was used. The case I sent had a split in it, when it came back the weld was the size of a 50p. When it was filed back it just fell out.... Result one wrecked case that could have been repaired with plastic metal,

Hi Ian Thanks for the pics. I reckon that's a long seat that's been chopped down to a single. Whoever did it has made a tidy job. Cheers Martin

Not had any success welding 30 year old oil impregnated magnesium . Tried it with various specialists over the years, and no luck with the clutch covers. For small cracks or splits a decent chemical metal (like JB Weld) seems to do the trick. I guess if you have a big hole in your clutch cover, it's worth trying to weld. Let us know if it works .

I have only ever seen 3 styles of seat on the 320. The short vinyl covered version with the SWm logo used from 78-82. The solid foam lower version 82-83 and the long version used on the TL320MW. Would be interested to see a photo of yours Martin

Ross. The front triangle section has the baffle and fibreglass packing in. The square part of the silencer has 2 baffle plates one with the hole at the top the other at the bottom. Unless the plates are loose and rattling, there's no point in cutting all of it open just the front section. I prefer to burn the carbon out ....think I described how to do this on here before . Re aftermarket silencers, the MadDog units that Kev Nolan uses and Dave Dawson had on his bike are straight through units. They rev great, but loose bottom end performance. I had Daves bike in over Christmas for a motor rebuild and tried the MadDog unit back to back with a standard silencer and found the stock one was better (in my opinion) Cheers Martin