feetupfun

The 247 is a model that went for many years with the same round fork sliders so it wouldn't matter if it was a 1972 247 or a 1978 247, they would be the same part. The word "Montesa" wraps around the curve nicely with fairly small letters. 348 has "M" probably because the square sliders that were introduced for the 348 in 1976 had limited space to fit writing (it wouldn't be visible as a complete word from any angle if it had to wrap around two corners, and the characters would be too small to see properly if the whole word was on one face). The replacement model for the 247 (the 248) shared the square slider design with the 348 and 349.

Custom rear sprocket carrier 520 chain Swingarm protector Chain tensioner retained by a screw Aluminium snail cams Aftermarket shift lever Rear wheel axle Standard-looking carby I still like that seat Be careful that the ignition cables don't get damaged by the heat from the cylinder fin Looks like you've made the new exhaust header

I'm still undecided Guy. The Majesty damper rods make the front end feel less busy than standard TY on stream bed rocks. The gold valves feel like the front suspension is more supple than with the Majesty rods and they provide an equally good (calm) feeling to the front end. Overall both make for a more relaxing ride in rocky stream beds compared with standard but I can't decide which is better. I find the Majesty rods make the front suspension action feel similar to a Bultaco front end. As for rough downhills with the front end loaded up, the Majesty rods work very well straight out of the box. The gold valves require careful setup to get the right balance between compression damping and fork spring rate and fork spring pre-load to be as good as the Majesty damper rods when riding rough steep downhills but are just as good for this when set up.

Wouldn't PW50 forks be too short?

The rubber dampers inside do develop play after a while. The rubbers can be replaced. I made new rubbers and rivets about 35 years ago for one of my TY175s, thinking that the play there might be affecting on-off-on throttle work, but I could not feel any difference in the behaviour of the bike between before and after, so I have never bothered doing it on any other TY175s. The subject comes up on these forums every few years.

I confess not reading the instructions with the damper rods and set mine to 125mm dip with Dexron ATF, rode a trial, then set them to 125mm dip with 5WT fork oil

It's a Victorian bike and Jared rode it at a Denman Club (Hunter Valley, NSW) event a few years ago ( a long way from home for both Jared and I). Are you going to make a standard shape header? That's a comfortable-looking seat. Did you make it? I bought a set of the Majesty brand damper rods too and am impressed with the damping action

Here is another TY250 (not mine) with a DT250 head showing the other side. It has the cut-away cylinder fins of the A or B model cylinder

Maybe there is also a thermal benefit with the DT250 head which could be important up here

What I think I can see apart from what you have already mentioned are: DT250 cylinder head. The exposed section of the fork tubes below the bottom clamp looks a bit longer than standard. Handlebar clamps are a bit further forward than standard.

Lifting the rear is a normal thing in trials riding. Some people call it unweighting the rear

Yes I bent mine to get the tip the right height after replacing the fixed footpegs with folding footpegs. I see the arm that the rod connects to on mine is at a completely different angle too

12 52 is good for trials competition use with a standard motor. 428 chain is good.

maybe crankcase contains a lot of petrol

I've ridden an EM 5.7 and found it did have flywheel effect. On any bike the smooth application of power has a lot to do with the mind-body connection of the rider. I have found that any bike (including the EM 5.7) feels right and works well once I have tuned myself to the way it responds.

I bought one like that from Keith Lynas

I'm wondering why you are limiting so much your choice of what bike to ride

Try Jared Bates at Southwest Montesa in USA

I'm using an OKO carby which gives a bit of clearance there

WES two box or good custom exhaust, ignition with a decent advance curve, free flowing airbox, lighten flywheel, non-offset carby-to-reed cage adaptor, light seat, light tank. Standard size carby is fine for 175cc

I've got a 348 (which is pretty much the same in that area). I usually fit the airbox last. Fit cylinder connector to cylinder, fit carby to cylinder connector, fit airbox connector to airbox, fit airbox

That was great to see. Thanks Dave

Here is I photo I have already showing the brake pedal. The bike in the photo is a very early M49 which shares many components with the M27, including the brake pedal. I will take more photos to show the pedal and mount better, maybe taking the footrest off I don't have any way to show the stand mount because I removed what was left of the broken-off mounting.

Q1 sounds like a restricted pilot jet or low speed circuit Q2 sounds like the fan motor bearings need some lube Q3 Yes make sure there is not too much transmission oil, then if it still does it, the gearbox may be getting pressurised

I can do close-up photos and take measurements if you want to make a replica