feetupfun

Sounds like a tight time challenge. Good luck. Those mudguards look great. There's a few things that MK 1 MARs benefit from that you didn't mention. The standard ignition wiring comes out the bottom of the casing and typically gets squashed between the bashplate and the motor. There's an easy fix by rerouting it out the front of the engine casing. Only a problem if the bashplate touches things. The fibreglass bashplate will fall apart real fast if it touches things. That carby may annoy you enough to replace it with something different. If the bike is leaned over, it will flood. The rear axle bends very easily. A common fix is to extend the hub to the right with an extra bearing closer to the RH end of the axle. Kits for this were very common back in the day. The axle holes in the brake backing plates are not all on the same centre as the brake linings. Common fix is to enlarge the axle holes. To get it geared low enough for modern sections using a small enough front sprocket you will probably need to machine the sprocket nut to provide chain clearance. If you fit 360mm shocks with that set of sprockets, the chain will need careful attention to its adjustment to avoid sawing into the cross tube under the lower chain run.

The Scorpa 125 fourstroke with the Yamaha engine is a nice bike and incredibly reliable and long lasting. They are fine to ride but were seen as underpowered by many potential customers

Should be only one ball in total, but if there is three then it is probably just a work-around for the pressure plate being too far to the right

Yes not all threaded clutch hub spring studs are the same length and also yours may have had the original studs replaced. Also there is more than one length for spring buckets, but you said it was the studs hitting not the nuts hitting.

I don't think this is what you were describing but maybe it might jog someone's memory

You can buy them from Yamaha shops

Yes I give many ****s about geometry and have a strong interest in the geometry of 1970s trials bikes. They are great fun to experiment with. I make my own drawings because manufacturers specs are way too vague, sometimes wrong and usually refer to an unladen bike. Modern bikes have excellent geometry already and people fine tune it with the suspension, handlebars and footpegs.

I just remembered how much I liked that avatar

Could indicate air ingress and if so, most likely the magneto side crank seal. Could also indicate a sticky throttle cable or slide. In neutral the revs should go straight to idle RPM when the twistgrip is released.

The only difference I can see is that chappo's frame has sidecover mounts that look like M198/199/198A/199A while the photo from the book looks like it would suit something earlier.

Doesn't matter if it is a 348 or a 349, a 26, 27 or 28mm carby would be ideal. If you post up a photo of the carby someone will be able to ID it. Same for the bike and motor. The engine number is definitely a 348 and frame is likely to be a 349 but 349 frames change over time, hence the photo.

I have a few sets of Magical fork springs in use and love them but am having trouble trying to find where to buy more from since Yamaha-Majesty.com has been incorporated into In- Motion

There's nothing wrong with asking noob questions. Rear tubeless trials rims have a groove that the bead pops into like a tubeless car rim and tyre does. The beads are so tight in those grooves that you usually need to break the bead with a special tool or using a bench vice or similar. It's a very reliable design. The original rim on your bike will have a sealing band for the rim well. These are rubber and get hard with age and the rim surface can become rough from corrosion. If it leaks there you can always try a new sealing band or use a tube. If your wheel is holding air now and you don't disturb the sealing band while you have the tyre off, it will probably work fine with the new tyre. Yes good idea not to take the old tyre off till you have a new tyre ready to go on. If it was me and the old tyre is really old (they have manuf date on them) I would have a new sealing band and a nice lightweight tube on hand too.

I ride 1970s off-road bikes. I bought a Tubliss for using with tubeless rear trials tyres on tube type rims on trials bikes but when I weighed the Tubliss and found it was heavier than a tube, I continued with my normal method of trimming the beads on the tubeless tyres to fit the tube type rims. The $160 Tubliss is still sitting on my shelf Your Rev3 should have a tubeless type rear rim and if the rim sealing band is still sealing, it will work fine with a tubeless trials tyre without a tube or a Tubliss. Some people have problems with the sealing band not sealing against the rim and end up using a tube to avoid air loss. Once a tubeless tyre is seated on a tubeless type rim, it usually stays put but there was a problem a few years ago with IRC rears in this regard.

I bought the right size perforated steel tube for my 348 in the form of a go-kart muffler core and it was very economical. I didn't need to curve it though

It's a non-standard hole made for the ignition cables to protect them a lot better than the standard hole which is underneath. If the cables come out the hole underneath, they tend to get squashed between the bashplate and the engine casings

Handling will be lighter with the WES and the sound is a bonus. Same for the TYoffroad TY175 exhaust. Lots lighter and sounds great

Now I'm really confused ?. I was thinking that Kiwis call them Jandals, a shortened version of Japanese sandals

Yes the 213 is a wonderful thing but does take a serious kick to start. I wouldn't be game to try in jangles which I suspect are the same thing as flipflops/jandals/thongs

The first models of Alpina (85 and 99) have a fairly short seat but the models after them are fine for two-up riding for two people depending on how big their bottoms are. No Alpina is what you would call powerful but the 325cc and 350cc models have enough suitable pulling power for two-up riding. I don't know what "shes quite up for a scooter" means

Normal thing to do. Can use most any automotive points ignition condenser. The important thing is to get a reasonably fresh one. If you go for a new condenser made in 1975 it may not be any better than what you are replacing. I usually look for one with a long tail and a nice mounting lug to make it easy to fit and connect up. I've had success with Bosch products made for old Mercedes cars

I have an array of 1970s twinshock trials bikes because except for two, they are the bikes I wanted when I was a teenager but couldn't afford. The exceptions are the TY175B which I did own at the time and a 250 Godden Majesty which is a bike I didn't even know existed until about 1995.

Larry I'm going to have a go at re-writing what I think you have written to see if I have understood your posting. "I can't find a Rickman forum. I've got Rickman Montesa and Rickman Hodaka project bikes. I bought the Rickman Hodaka frame from a wrecker in Michigan. Most small Rickmans are for Zundapp engines. The frame has a H stamp. I found parts to complete it on ebay. The 100cc motor runs and shifts. The forks and wheels are from super rat 125. Either the motor or the frame is 6/71 which was on a small tag on the left side. The whole project has cost $US1500 so far. The motor is either stock with some Super rat parts or I might try and use some super rat parts or I might look for a better performing Hodaka engine. The gearing on it is very high. The Montesa did run but a few hours after I bought it, I found it had a broken gearbox shaft which needed the cases split and parts to fix it. The motor is the same as what came in a 1973 250 Cappra VR. It was stored in a barn in East Washington State for 20 to 30 years, was ridden by two brothers then a son. It was delivered to me. I could not believe how high the compression or the power was for an old engine. I am sure it has a pickled cylinder. It has rust in the tank and wheels. It's been pulled apart and stored in boxes. I have bought parts to fix it from a dealer in Oregon for when I can get to it. I've rebuilt some Bultaco motors. These Rickmans are not for sale. I like seeing photos of Rickmans but there are not many photos on the trials forum. I lost my Rickman photos when my other PC died. There are pictures of me at "Happy Hodaka Day"."

Not related to the liquid compatibility as such, but there is an issue with modern pump petrol forming a very strong and adherent gum when it dries out.

If it's just the brake action you want to improve, why do you also need to swap the shifting over? Lots of people ride trials with shift and foot brake on the same side