steve

Ok, so this is a bit late, but I did get to the bottom of the problem. It was a carburation problem as I thought all along. So the std Amal must have a blocked drilling in the pilot circuit. No amount of cleaning managed to dislodge it. The 26mm OKO turned out to be a Chinese copy. It was after I'd tried the OKO on a TY Mono and had exactly the same issue, the penny dropped. I had a Keihin PWK28 flatslide off a Gas Gas 125, so put that on the Armstrong, WOW, bike was suddenly running almost perfect. Just a clip on the needle and a different pilot jet was needed.

I spent hours trying to work out the forces etc.... Came to the conclusion that the leverage from the cam would be slightly weaker by moving the arm to the front. But I did it anyway on my Armstrong, mainly for the cable run. I was wearing a hole in the bottom yoke. On braking forks compress and you can feel the effect on the lever as the cable is bent. Fitted some new forks as my old stanchions were knackered, so I needed to make some bits anyway. I made a custom mudguard risers with a cable pull anchor (drilled and hollowed for weight saving). Custom fork brace which is flatter and helps reduce twisting. Also made a nice strong torque arm. I tried to keep all the angles optimum for best efficiency, which meant a new brake arm with slot at a different angle. Less outer cable = less flex and no deflection on fork travel. I used 2mm Cable, but I also have a 2.5mm to make up to try. Tested it Saturday. Overall result = Awesome Works better that I'd hoped, lever feels so solid, not too vulnerable for damage and I think it looks good too. What do you think? Sorry to muddy the SWM forum with pics of an Armstrong!

Hi all, I recently bought a used TRS 250 RR and so far I've been delighted with the bike. I went through the rear end greasing linkage and swinging arm and was very pleased with how easy it is to work on. My only minor gripe I found was the airbox lid didn't fit very well. I remember seeing the bike once with the previous owner and noted he was using a ring of pre cut clear vinyl to cover the gap. The problem seemed to be the sides of the lid were lifting up, i.e the lid had flattened. Having fitted a clean air filter I didn't fit the lid immediately, instead I put the lid in the vice and gently squeezed it closed a little and left it a week. Today I removed the lid and was delighted to find it now fits perfectly. I did a little search and didn't see anything else posted about this, apologies if it's already been discussed to death!

Can anybody help with jetting for a Mikuni VM26 for use on the Yamaha TY250R? The carb is new and was supplied supposedly set up specifically for this bike but it is way out. It'll barely run past idle it is SO rich, as if the choke is on. Supplied jetting is - Needle 5L8 Needle Jet 182 N8 Main 125 Pilot 35 Slide 2.0 Or at least I think this is right as I can't see the flipping numbers and had to photo them and zoom in as best I could.. Thanks. Steve.

Just stumbled across this post. Some great work, the lever bushes have long been on my to do list. I spent a long time looking to see if I might be able to fit a little needle roller bearing in there but couldn't find anything suitable. Anyone else find the right bearing? I think the feel would be greatly improved.

interesting, especially the 11 x TRS, with 3 of them taking awards I believe.

Thanks, that killed a few minutes

Interesting to read peoples opinions, I suppose what we are looking for from an aircooled engine now is very different from the 70's / 80's & early 90's. In the day the bikes were ridden by riders in their prime doing full Nationals and OTC road Trials Etc.. We'd think nothing of losing 80 or more marks every week. The sections and events the bikes are being used in now have changed, not many mud bogs and climbs now and severity is far, far easier. Tighter sections on closed courses. People using a Twinshock tend to be over 40's, often riding easy routes in trials such as Kia rounds. Several lads have demonstrated even an 80cc bike is capable enough so hardly surprising the little 156cc Fantic is a popular choice.

I've shared this before but thought you might like to see me riding my 92 Aprilia, bit of inspiration for your project perhaps! https://youtu.be/UqcqkP5qN5s

I'd go back over the carb again, perhaps get it cleaned in an ultrasonic tank. If it'll only run on choke that's telling me a blocked jet / passage. What carb, I can't remember that long ago!! would the Sherco carb fit to give it a try? Might not be jetted right but should give you an indication.

I'm making a weekend of it with another rider and his family so we are looking for a camp site to stay 2 nights. Must have toilets and showers. It'd be nice if there were things for the girls and kids (between 11 + 15) to do whilst we are riding. Don't mind a little drive from Trial, if anyone know of a nice site?

Smashing video.

That's an interesting issue, I'd have thought the training would help. Perhaps you are not reacting to the dynamic forces fast enough. Lots of things throwing you off balance compared to your static training. More bike time,!

I made a tool with nuts and bar as I have a welder, however I remember visiting a friend many years ago who was doing the forks and they simply rammed a wooden broom handle down the forks, the end had formed itself into a nice hexagon.

I am interested to know if this has a detrimental effect on your trials? I used to ride with a guy who does weight lifting and he was so stiff and rigid on the bike.