motoswm

Just loaded parts books, engine manuals and other info for most of the SWM trials models. Available to view or download here http://www.motoswm.co.uk/tech/

Hi, thanks for all the comments. Since taking the photos in James report, the project has moved on. When the bike arrived it was seized solid on the kickstart. I pulled the motor apart and found that the oil had started to solidify and was enough to jam up the kickstart. I took the entire motor apart, spent hours on the parts washer and rebuilt it with all new bearings and seals. It has had new throttle and clutch cables, new plug, chain and fresh fuel and oil. Apart from a bit more of a clean up it has remained untouched and will stay that way.....even down to the very cracked original Michelins It gets a ride around the field most weeks and handles a runs great. Will it ever get ridden again in a trial ?? .......well that's up to Bernie. Martin

The 2 holes for shock mounts are original. The forward mount with the nut is for solo use. When you use the pillion (passenger) footrests which attach to the hole through the side of the swingarm you use the rear shock mounts to increase the damping.

I sent a message to Mauro Sironi. He doesn't have the exact production figures any more, but for the trials bikes between 77 & 83 he reckons about 3000. The Rotax engined Enduro models for the same period 5000. Cheers Martin

These are now being remanufactured....problem sorted

Sorry guys been a bit busy....yellow and black wire for 125 kill switch

The other area to consider is the swing arm. The distance between the swing arm spindle and bottom shock mount on the steel units is longer than on the later alloy Jumbo type. Various differences on the stock footrest positions, I will try and take some photos later in the week when I get back

Ross, there are about 4 different clutch centres an 3 different depth baskets, Add to this the washers either side of the centre bearing on the clutch......same thickness on most 320's.......one thick and one thin on 125's, some enduro 250's and some of the early 320 Guanacos........which is 1mm difference and the same as a metal plate. I have tried pretty well every combination of the above, there isnt any that make it better, plenty though that make it worse. Stick with the standard set up where possible.

Take a look at the following, its the SWM 240/280 clutch set up You will see there are - 6 x Friction plates 5 x Metal plates - 1mm thick 1 x Metal outer plate 1.5mm thick I have found that the Sureflex kits do not run exactly the same thickness plates as the standard Rotax. Easiest thing to do is measure the combined thickness (stack height) of your original plates and compare it to the stack height of the Sureflex ones you have fitted. If its slipping, my guess is that the Sureflex plates will be a lower stack height than the originals.

Hi Need a bit more info. Is it still making the noise or did it just happen on the two occasions you mentioned? Have you drained the oil to see if there's anything floating about in there ? Gearbox problems with the Rotax motor are rare. It happens occasionally on the enduro lumps when they throw a chain at speed and the final drive shaft bends. Would have problems selecting gears and would make a noise all the time if this was the case. More commonly though the 2 D clips that are on the end of the gear shaft will break...easy way to check. See if you have any movement in/out on the gear shaft. If you have, you will need to split the motor. The other cause of the noise you are describing is the clutch. Pop the cover off and check for any signs of anything touching the inside of the cover or outside of the basket. Check the clutch has not come loose or the 6 plate retainer bolts are coming undone. I have plenty of spare gearbox bits if anything has failed, but would think it's unlikely. Give me a call if you need more help Martin

Yes, its privately owned and has been for about 15 years. This one has the original matching frame and engine numbers, and I've even seen the log book. Think there would have been more than one development Bultaco in Sammys hands at any one time, this one is probably identical to the one in the museum, no doubt would have had bits swapped between them....just happens to be the bike that was registered,

Yes, you can run without the counterweight, the early red/white SWM's and the later Aprilia TXRs ran with just a nut. You will need the correct nut, I have a couple here if you want one You dont need a impact gun to remove the weight, just a half inch drive ratchet/bar. Either hold the flywheel, to lock the crank and remove the counterweight (std right hand thread). Or you can lock the crank directly......look between the fins on the crank case, just below the exhaust port, and there is a 13mm hex head bolt. Take this out, poke a clean screwdriver down the hole and it will touch the crank. Slowly rotate the crank, and when it reaches top dead centre there is a hole. If you find a long M8 bolt and screw this in, it will lock up the crank to remove the counter weight or flywheel nut. Also handy, if you need to set the disc valve. Cheers Martin

Hi Ross The military motor uses a Bing carb as its based around the early RSGS enduro motor. So the carb rubber will be too big for your Dellorto. I have a couple of new original 125 carb rubbers here.....but the hole on these is too small for the 320 valve and carb. Martin

Welcome to team SWM With Marzocchi forks your bike is a 1980 model 1200cc of fully synthetic light gear oil in the motor 220cc of 10w oil in the fork legs 50:1 fully synthetic Premix Carb settings

The Italian government got involved with SWM. They planned a second factory elsewhere in Italy to produce road bikes to rival the Japanese who were starting to take a big slice of the Italian market. The original SWM factory was based in Milan and was producing around 7000 bikes a year. The trade unions believed that the government involvement would eventually shut the Milan end of the operation down and thinking that there would be huge job losses, instigated a series of strikes and factory sit ins which eventually crippled the firm. I think at that stage, Pietro Sironi owned the whole company, he sold it to his family who started up SVM, which never quite got to the same level.

Just found this film of the SWM factory from about 1978.........how I would have liked to take a trip around there. https://www.facebook...&type=2

I have a 125 front pipe and middle box here. You need the middle box to suit the smaller diameter front pipe. Rear tailpipe is the same for 125 & 320 Martin

Here you go

Heres a flywheel that I took from a 240 Armstrong Rotax, this ones been reduced by 50% vertically. Might give it a try to see what difference it makes.

Ross Are you using that dodgy Aprilia carb ?? Would suggest you look at the main jet first. I have had a few that have tarnished so bad that the standard 95 opening is reduced to a fraction of that size and they wont rev out. If that doesn't cure it, and its smoking a lot when you try and get it to rev out, it could be the disc valve crank seal or O ring....you can check the settings when you change them. Martin

I have points and condensers if you get stuck. To hold the flywheel I use a strip of steel approx 25mm x 5mm x 450mm long with an 8mm hole drilled in one end. I bolt this to the side of the flywheel (using one of the 3 threaded holes) and then use a socket and torque wrench. As you rotate the flywheel the strip will lock onto the top of the footrest allowing you to unscrew the nut.

Hi Ross I have used RAL5002 on my blue frames. Hope this helps Martin

http://silodrome.com...orenzo-buratti/ Now I realise where I am going wrong. Dont restore them back to original.......just sell them off as "custom creations"

It's an Aprilia Climber bottom end with an air cooled barrel and head (apparently they will fit straight on !) Bike is also using the swingarm from the Climber that is longer than the standard SWM unit and gets the wheel base back to normal after the front end was altered to suit the "modern" forks.