oldaz

Thank you, I'll check the space available at the drive sprocket and the chain guide - looks like it will be a standard type chain.

I read somewhere to not use an O ring type drive chain? So many options, gold, plain, O-ring, X-ring - what's best and why one type over another?

Thanks Graham, when I measured the bike I figured the rear mudguard needed to be at least 980 around the curve. the Gonelli rear is 930 (don't quote me) and the Stilmotor is just over 1 metre, so I went with the longer option figuring I can always make it shorter if I need to.

Looks great fourex. I've got to a point where I have to pull my head in a bit with parts for a while. Hard chroming $360 plus shipping each way, handlebars $110 for Renthalls, muffler $250, chain $85, need to replace the spoke nipples in 2 wheels, probably spokes as well, so another couple hundred there and I haven't looked at the power unit yet. Way it's going it's going to be a 7k bike when it's done. Anyway, I bit the bullet today and ordered the rear mudguard from inmotion.

I appreciate the comments fourex and I know it's longer, but it's what was on there to match up with the muffler that came with the bike and can always be shortened if needed. The muffler that came with the bike is a serviceable type where you can strip it and add/remove filling and is rubber bush mounted. I would like a genuine one but am not prepared to pay over $350 to get one here. Just got a response from RAD in Brisbane to refurbish the fork tubes at $360 plus shipping each way, apparently there's nowhere in Melbourne that do it any more and RAD have the market. I haven't been able to find replacement tubes either - makes me wish I still had my engineering connections who could easily modify a set of common size tubes from a different model. I may still attempt to try that. Any idea where to get the plastic trials type rear mudguard in Oz??

Thanks Graham, I've sent them an enquiry. I'll also check if anyone in Victoria is doing that sort of work.

Got the new seat back from ACM seats in Melbourne, Pete did an excellent job and built it on my custom made base in the Ulf Karlsson style. OK it wasn't cheap and I had to make the base myself, but a LOT cheaper than a genuine Ulf from Europe - and it fits :-) Also finished off the new alloy chain-guard and finished repairing the foot rests - what I would consider productive - think the rest will slow down a bit now. BTW using all stainless steel fasteners as it goes back together. Also need at least one good replacement fork tube/stanchion - any clues where to get one??

(Thanks fourex, I'll check them out. I also found one on a Spanish site last night for about 8 euros, but shipping to Oz was over 80 euros, making it into a very expensive part.) I ended up making one, took about 20 minutes, used a block of hard rubber and filed to shape with a wood rasp, finished off with a ******* file - jobs done :-)

I'll be facing a similar problem on mine when I get to the tank. Plan A is to remove the damaged bottom of the tank section and glass in a new section. Plan B is to remove the bottom altogether and fit a smaller aluminium tank, then fit the original as a cover over it. Probably have to do something with the filler, but it would retain the original look and seat mount.

Finished welding repairs and got the first coat of black on the frame and swinging arm ready to go back in.

The "summer project" seems to have started a bit earlier. The more I took off the bike to find out what I would need to bring it back to life, the more I found needed repaired or replaced. The price on the parts has long passed the initial purchase price and probably still another $600 or so to go, but that's what you get with projects. I eventually got the frame stripped right down and sand blasted so I could do a full inspection. Sadly there were cracks I hadn't expected as well as all the broken mounting tabs and stripped captive threads. The frame now has a custom strengthening collar around the top of the front down tube, the cracks there were ground out and welded, stress relieved and ground smooth, then the collar welded over the repaired section to overlap the double walled section already there. All missing mounting tabs replaced including captive nuts welded where needed, swinging arm also.

Thanks fourex, I'll check them out. I also found one on a Spanish site last night for about 8 euros, but shipping to Oz was over 80 euros, making it into a very expensive part.

I'm in the process of stripping down the Ulf Karlsson I recently bought, to identify what parts I need to restore it. When I pulled the swingarm there was a rubber guard sandwiched between the front of the swingarm and the rear frame cross piece. It was roughly "H" shape in section and was there to stop the chain damaging this area. It had obviously been reversed at some time as there is significant wear on both surfaces. I'll try to attach a rough sketch of the cross sectional shape in the hope that someone may recognise whether it's actually a Montesa part and where I might get one from.

The picture of the front forks in your manual looks very similar to the 247 forks. They use 2 seals in the top of each lower leg, the lower one to keep the oil in and the top one I believe to keep the dust out. The size on the 247 seals is 35x47x7 and a circlip hold them in place.

Thank you, but they are different shape and I'm going for original where possible. Cheers. Latest news, using a different search function I just located and bought a complete original set, thanks to all for helping.

I guess I figured it couldn't be that easy - top and bottom clamp are same shape, same holes for forks, but stem hole is about 5mm different to give trailing angle of forks.

You're right, it's a bottom clamp. I've been in touch with David, he's measuring some stuff for me. Seems the bottom is the same as the top except no threaded holes for the handle clamps, but waiting for confirmation. Thank you.

Thanks Fourex, got it and will keep you in mind. Currently chasing a top for the triple tree, the one on the bike is badly corroded, looks like acid or something has attacked the aluminium - you may be able to zoom in on the top piece in this picture. I'll be chasing up various parts in preparation for the project, taking lots of pictures and comparing them to others on the internet as I build parts and repair lists. So far the list of parts looks like it will cost over $1200 just for parts, then postage as most stuff looks like it will have to come from overseas. Plan is to photograph and document everything that's needed, everything that needs or can be repaired, find where I can get parts at reasonable cost, then strip and clean, inspect and repair, then paint. When I get to assembled and working stage I'll make up my mind whether I put original style lighting on it. I'll post pictures of progress when I start actually working on it.

You're not alone, even though I'm in Australia. I just bought a "Version Ulf Karlsson" Cota 247 in very poor condition. I used to ride trials late '60's - early '70's and couldn't leave this thing to die - I plan to bring it back to life over the coming summer. Who knows, maybe I might get back into trials on it - if they have a class for over 70's - years that is :-)