feetupfun

They used rolled plate because that was an economical way to make them. What do you think the expensive modern aftermarket yokes are made from?

Man that sounds a lot of $$$ for those yokes. They are so plain and simple. I know Jared Bates advertised NOS ones about 6 months ago for very low $$$. Jared no longer sells Montesa parts but the person who bought Jared's stock advertises Montesa parts on eBay (USA) Have you looked at the Spanish shops that sell trials bike parts from that era?

metisse while the alloy LH pedal does look nice, the ones I have seen in use and ridden with are not very grippy when wet and I've seen plenty snap when they whack into a rock.

They can drag for a few possible reasons: The plates may not be moving parallel when pushed, although it sounds like you have been pretty careful to avoid this. There can be grooves in the basket fingers that cause the plates to push together if they see any contact. One or more plates may not be perfectly flat, meaning that the axial travel of the pressure plate may not be enough to free the plates from contact due to the increased effective thickness of the bent plate/s. All-steel plates spanish clutches typically have a long engagement because the plates are not quite flat. The original plates are stamped while modern replacement plates are laser cut, so they are flatter. As well as starting out not quite flat, steel plates sometimes distort with use, because they are so thin. the flatness of the plates can be checked on a flat surface like a quality piece of glass or a surface plate if you have one. It's possible that when reassembled, the plates were not put back in the same sequence and position in the basket and the effect of any grooves in the fingers may be now more severe. There may be insufficient axial clearance between the clutch hub and the basket and this may make the problem temperature-sensitive. If the clutch action improved again once the motor cooled down then I would be looking there. Next time you assemble the clutch put some oil on the plates and you won't have to worry about them not having oil. From what you've said i don't think that lack of oil or too heavy an oil is the problem. I use car manual gearbox oil in my Cota 348 clutch casing and it doesn't drag.

In that case you could use a thinner gasket for the magneto cover or use a slightly longer pushrod or shorten the pushrod by just less than a ball diameter and use two balls

You say it is dragging and later say it is grabbing. Is it doing both or just dragging? Dragging can be caused by lots of things but on an all-steel clutch, grabbing usually means lack of oil

You can fit the arm to the next position on the spline

You can measure the ID and OD of where it fits and buy a gasket from an exhaust shop or off the internet. There a few different types and which one works best depends on the geometry of the joint and how much movement it is going to get in service. Google "exhaust gasket" and you'll see what's available.

Dan what would be a common use for that Everclear product? There's nothing like that available here.

I didn't even know that disinfecting was a thing. I just wash my helmets out with warm water.

Very hard to diagnose over the internet using words. Can you post a video on youtube of it misbehaving?

Don't worry chappo I got the 348 out again today and have now fitted the plug to the central spark plug hole and it all fits fine. The other night when I looked at it I didn't twig at the time that you can very easily access the plug with the tank tilted up

Maybe there were more than one 348 exhaust pipe design. With mine it would be extremely hard, maybe impossible to get the cap off if the plug was in the central hole and it was a standard height plug. I see in the brochure photo, the plug is in the central hole but also in the brochure photo showing the left side of the bike, the exhaust looks different to mine where it goes over the head, maybe a smaller diameter pipe. I'll have a better look at mine on the weekend and try and work out if it is different to the pipe in the brochure photo.

I just had a look at mine. If you can remove and refit a spark plug cap on the plug when it is in the central hole with the exhaust in place, I'll be very impressed

Does it all still fit nicely with the exhaust pipe in place?

Yes they normally use a barrel that fits in the end of the brake arm and a nut on the adjuster thread. What advice do you want? I could do a photo of mine if it will help

Like this one?

Don't throw away the standard fork yokes. You may decide to revert to them after trying alternatives.

Have you got a photo of what you are after? I'm a bit lost by the description

One 348 I bought in about 2000 still had visible cross-hatching on the fork tube chrome and in the cylinder bore and it still had the original sprockets, handlebars, levers, cables etc. It had been ridden in trials but very little. I have a suspicion that some people bought them new and found that they were not as easy to ride as they had thought and just parked them up

Yes you can normally operate a clutch actuation arm like the one on your bike with a suitable tool to increase the leverage but you might have to make something due to the space being a bit tight on that motor. I have previously operated a clutch arm on other bikes using an 12" shifting spanner to provide the leverage. It's a very common thing on those motors to bend and sometimes crack that arm next to the weld

What ignition system? What plug gap? What fuel? What premix oil? What does the spark look like? Are there any whiskers on the used plugs? Did the fuel type get changed recently?

Corroded yokes is a common thing with 348s but there are usually some being broken down for parts in the UK. Be aware that the yokes from a 247 look very similar and will fit, but have slightly different geometry. Both 247 and 348 yokes were made from rolled aluminium plate which lends them to that sort of failure. I saw some NOS 348 yokes advertised a while back in the US. Sorry not allowed to mention suppliers on here. As for water getting inside things, one of my 348s came with collapsed forks and I found they were full of water. Lots of corrosion on the insides of the tubes.

That sure looks great. I'm intrigued with the black shields/guards inboard of the footpegs

Wow we had one of those CZ scooters too! I also remember our CZ scooter was 12v electrics when most bikes were 6V