oldaz

Mine has +30 thou stamped on the piston, so I guess it's like car engines where oversize usually goes up in 10 thou increments. I think maybe a better option is to see what size piston you can actually get before you bore it out. I used to repair drive shafts by welding and it was often difficult to get them 100% true to centre - in that industry/application the shafts were in slow rotation so being a few thou out didn't matter, but in an engine turning a few 1000 rpm they need to be 100%.

Almost finished rebuilding my VUK and finally got to TRY and install the kickstart return spring I got from Inmotion. Problems are, the hook that goes in the notch in bottom of lever is level with the pin that goes in the case - so the spring has to be "wound up" half a turn (180 degrees) to get it in there - if this is even possible. Second problem is IF I ever get it in there, when I operate the kicker it will load the spring another 180 degrees which seems way too much tension - I don't think the spring would last long this way. Does anyone know the correct method to fit the spring?

If you really want to build it yourself, do yourself a big favour and check out Michael Waller's video's on youtube before you start.

This type repair has been done since welders were invented, so it's indeed possible. However the cost will be extreme unless you can do it yourself, and in this application it will be difficult to get it 100% true. I've seen cranks on eBay that would cost less and a better result. I'm almost finished a complete rebuild on a basket case Version Ulf Karlssen 247, so appreciate what you've been going through, also appreciate how much it costs to repair/restore these things.

The picture is "photo-shopped" from the 247 parts manual, I just took out the part numbers and assembled the kick lever on computer to demonstrate what I was talking about.

Thanks, but I'm referring to the external kick-start lever and it's return spring on the 247 engine. The inner part of the spring locates in a hole in the timing cover and as near as I can see, the outer part has a hooked end to locate in a notch in the clamping area of the lever. Problem as I see it, is the spring has to be pre-loaded by half a turn to get into the notch, then it will be loaded a further 180 degrees as the lever travels through it's throw. This puts way more tension on the spring than is needed, so I ask the question "is this arrangement correct"? Or maybe do I have a wrong lever?

Now I have another question re the kick start return spring. I've looked at the drawings and the spring from Inmotion and the lever appear to match the drawing in the parts manual. I assume the hooked part of the spring goes into the notch at the base of the lever. To assemble these parts the spring will have approximately half a turn of tension on it with the lever in the home position. That means a full turn of tension at end of lever stroke - is this normal? It seems like a lot of tension, certainly far more than is needed.

If it's got an Amal carb, you can download their "Carburettor tuning guide" which takes you through all the steps needed to get it right.

Near enough $250 Australian plus shipping from Spain - last quote I got was 80 euros (about $125 A) shipping from Spain for a small part - makes for an expensive silencer IMHO.

The original steel pusher was totally trashed, so made a new brass one with an oil groove across the face to replace it. The 3 leg pusher was really badly scored from the steel to steel contact, so set it up in the lathe and re-cut the contact face - made it slightly convex to help centralise the brass piece and improve lubrication at contact point.

Back on the rebuild topic, I've managed to get a bit more done - exhaust system rebuilt, put new guts in expansion box, straightened and knocked the dint's out and heat wrapped the header pipe, then fitted the new silencer - all parts painted with high temperature semi-gloss black - continued with stainless fasteners. Completed the carburettor, fuel line, fuel filter and airbox. Waiting on kick-start lever from chrome plating, so now moving on to tank unit refurbishment - will have to brush up on my fibreglass skills. Checked tightness of fastenings all over and added lubricants.

Being in Australia most of our gas is non-additive, not all petrol stations sell ethanol gas, so we don't have a problem and still have a choice of 3 octane levels. The general rule is if the vehicle is over 10 years old, don't use ethanol gas. Son in law did in a collector car and it cost him over $500 to get everything cleaned out and all new rubber though the gas system - took about 6 months to get the thing running right again - then he totalled it. I use 40:1 synthetic 2 stroke oil with 91 octane unleaded, it doesn't eat rubber or fibreglass, but tends to go off if stored too long.

Had to go to shop, but capacities I have are - clutch = 200 cc 10/20w or ATF, gearbox = 300cc 10/40w or 75w (should be a GL4 oil due to brass/bronze parts in there), forks = 190ml 10, 20, or ATF (use different weight oil to suit rider, but action should be "soft" compared to dirt bike), original mix is 25:1 with engine oil, but modern synthetics can run up to 50:1 - I use 40:1 with top grade oil and non additive unleaded gas in my older 2 strokes. Others may have different opinions about the mix, depends on type of fuel, type of oil and whatever works for you.

Yes, outer one is clutch, lots of people suggest ATF in there, second one is gearbox, originally supposed to be SAE-80 gear oil in there, but modern multigrade is used by some. I don't have capacity to hand, but you need to fully drain what's in there, then add the correct amount as there's no recognised way to check the levels. Also I believe your bike is pre-'75 as it has the under clutch arrangement. I'm told '74 was the biggest selling model. Frame number is stamped into the left side of the head-stock and engine number is stamped into the top of the front engine mounting lug of the crankcase. Usually engine and frame numbers match from the factory and will start 21M????

Both fair comments guys, problem is Motosolex's bike came in pieces and he's trying to figure out how parts of it go back together. Whilst there are a lot of differences in the 2 models, the assemblies are similar. The front hub in the picture above is very similar to the hub in my bike and as such the bits still assemble basically the same way. So if you look at a front hub with speedo drive that works the same way as another that looks similar, mechanically they will assemble in a similar manner, only the dimensions may be different. I've explained how my speedo drive and spacers work and the bits he has are similar, so he just needs to sort out the bits he has to make the assembly fit. From an assembly point of view, it doesn't matter what the fork spacing is, the wheel has to go in the middles, so if you get the guts of it right, then you only have to work out which spacer goes where and that's what I'm attempting to help with. Hope that makes sense. I suppose I should mention when I got my bike, the front wheel was in backwards and the speedo drive was hanging in there but trashed (like the rest of the bike) so I had to delve into how it was supposed to be assembled. This meant studying the parts sheet for the particular wheel assembly and figuring the mechanical logic for why it was made this way. After that it was fairly straight forwards to figure out what needed to be done and how it fits together to make it work. I don't intend to fit a speedo, so didn't waste any more time attempting a repair on it, so I designed and made a new spacer to completely replace it, but staying true to the original design concept. The new spacer matches the outer of the original and works in conjunction with the original type seal, while meeting the criteria for the total assembly width to fit between the forks. I had to get personal with it to figure exactly what was needed and it worked out fine - even looks like it's supposed to be like that.

Wheel looks the same but the speedo drive is quite different on the inside. Looking at your second picture, it looks to me like the stepped spacer goes between the wheel bearing and the speedo - one diameter will line up with the original seal that would be against the bearing. The bit with 2 prongs on it locates in the slots in the wheel hub, next will possibly be the small spacer you have arrowed in third picture, but you'll need to figure which way around it goes for the recess to line up, next should be the speedo drive unit and finally the stepped spacer shown on the axle in third picture - the larger diameter goes against the fork leg. Spacer on the brake side is about 15mm wide to align the wheel in middle of forks. Hope this helps.

Looks like same wheel as mine, I still have the speedo drive and associated bits in the shop, so I'll have a look when I'm there later today. The flat and spring washers in the last picture look like the originals for the outside of the front axle. Axle nuts go on left (brake) side of bike.

Do you have the parallel or tapered hub? The positioning of the spacers will generally only work one way to centralise the wheel. With the speedo drive in place - if it's same as 247 with 3 tabs holding it - the spacers will be similar both sides. If you have stepped spacers the larger diameter goes against the forks. Inside the hub is usually a stepped sleeve carrying the wheel bearings, then a seal on the brake side that matches to the boss on the backing plate. I'm told if you use fully sealed bearings you don't need the extra seal, but I used it anyway. If you don't use the speedo drive, you'll have to make a wider spacer for that side.

Maybe start a new topic and ask about the 349 clutch? There are others who should know more about it. Those springs look like a later version of ant-rattle springs and I don't think they will make much difference to what you want to achieve. Remember the clutch lever puts a huge pressure to release it, you have the lever at the handlebar ratio multiplied by the lever at the outside of the gearbox, then the tiny lever inside the case, so lots of pressure needed. You might be able to set a strong bar across the plate with a clamp each end?

Like I said earlier, I haven't worked on other Montesa models, but it looks to me like there's pins coming through the basket from the inside and being held in place by those small, maybe 3mm pins that locate into the cover. I assume the clutch pressure springs are on those same pins, so I would look at maybe compressing the clutch and take out those 3mm pins, then the cover should come off?

I made a new pusher, did some work on the lever arrangement and refurbished the 3 leg pusher, but I didn't strip the basket as it looked good. That said, your clutch looks different to mine in the way it's assembled and it doesn't appear to have the little anti-rattle springs around it.

Slow going due to other priorities, but I manage to keep chipping away at it - with the power unit back in the frame I've managed to complete the clutch set-up, complete the timing side, fit chain, overhaul and fit carburetor, throttle cable done, single wire for coil works, chain tensioner works, kill switch wired in and then started to fit the air box. Rear mudguard was too far forwards at the front edge (if you've been following, the mount was missing, so I guesstimated where the new one should be) to allow the air box to fit in, so back wheel out and mudguard off, make up and fit new front bracket extension, modify mudguard to suit and put it all back together. Have to get new stainless clamps to mount air box, then I can move on to exhaust. The exhaust poses a few problems, not the least being the damaged clamp nut and most of the thread is missing from the barrel - another challenge ahead. The Ulf Karlssen stickers for the tank/seat unit just arrived so the end is now in sight - still have to repair the fibreglass and re-paint though.

Looks like PO lost the steel slips that go between the brake shoes and the actuator, so came up with their own version. At least yours had linings on them :-) Mine had one lining on the rear with the other one lying in the drum, no linings on the front and a bead of silicone around the front backing plate.

Hard to envisage unless you have the parts laid out in front of you. For want of better terminology you have the shaft, end spacers, circlip, spring, inner and outer ratchet sections (what I call the outer one is the one with the ramp on the side of it - also the spring goes in it) the "keeper" that is held into the case and the inner and outer bushes - the inner one is in the blind hole in the crankcase half. I believe the first thing to do is set the shaft in the outer bush and rotate it so the stop is about 1 to 1.5mm from the case web (where the damage is) and clearly mark where the kick lever goes - it should be one spline past BDC when the shaft is in this position. Reasons for doing this are that it's very difficult to kick the lever any further past BDC and it helps to ensure the lever is in the right position when it's in the home position - it can be difficult to decide if the home position is exactly 1 o'clock or maybe 5 past 1, which could cause damage all over again. You need some end float when it's finally assembled (about 1mm should be enough) or the mechanism will tend to stick and be hard to return to home. There's only one spacer shown each end on the drawing I have, but I believe there should be a second one on the outer end so there's one each side of the circlip, otherwise the spring fouls on the circlip or the circlip bears against the bush. Make sure the inner bush is pristine, because the spigot end of the shaft only goes part of the way into the bush and it will self destruct over time - I made a new replacement out of good quality brass and cut a small oil gallery into it as it's much stronger than the oilite type original. The outer ratchet section must go on the shaft spline so the flat part of the ramp (not the wedge section) is held by the keeper. You will notice the keeper can be rotated and locked in place by the nut, so set it as close to the wedge as possible - if you're looking at the head of it, set it as far clockwise as possible. Like I said, hard to explain unless you actually have all the bits in front of you. By using this set up the ratchet will engage cleanly in the first position so you get a positive engagement as early as possible and because the kick lever can go slightly past BDC there's minimal tendency to over-stroke and damage the case. I used the OE spacer on the outside with a second one about 1mm thick between the circlip and spring, making sure it fits into the top recess of the outer ratchet section - this spacer bears against the circlip and the spring, adding slightly more tension to the spring and also keeping the spring square to the shaft and bearing evenly. Due to the design short-comings you can't use a thin spacer on the inner end, even though it would be much stronger as the spigot would go full depth into the inner bush, so you're stuck with the 4mm (approx) spacer there. It wouldn't have taken much extra development to have a longer shaft. Also when you fit the new bushes, put the shaft in, temporarily put the crankcases together, then put the side cover on and make sure the shaft doesn't foul in the side cover, I had to relieve mine slightly to ensure I had a good return - the lever spring would have done the job, but a bit of crud in there would have made it difficult.

The frame repair meant fully grinding out the tubing cracks to expose the extra tubing inside, then welding to the inner, welding it shut, dressing the weld, repairing the edges of the original gusset/s where cracked and welding them back to the down tube, fabricating the "wrap" reinforce, tack on one side and clamp tightly to the repaired area and finally fully weld in place and clean up. Where it was cracked at the rear support, simply grind out the crack, weld and clean up. By "grind out the crack" I don't mean V it out, I cut the crack right through, then rebuild - extra work, maybe not really needed, but there's no crack left to maybe start over - yes, it could crack beside the weld, but stress relieving it should minimise the risk. Cracks in the head-stock area appear to be caused by a combination of dropping the front end heavily (imagine coming down suddenly off a wheel stand and you get the idea) and poor design in this area. The internal reinforce ends almost exactly where the gusset/s end creating an area of flexing, so a weak spot. It could have been much stronger by either extending the gusset/s another 50mm or so, or extending the internal reinforce a similar amount. A different material may have also been a good option. Test run won't happen for some time yet, lots of little things to sort out yet and some extra little bits to make and fit to help with maintenance. Exhaust system to rebuild - need to burn out primary muffler, open it and repair inside, same with rear non-original silencer, then the fuel tank. I'll probably strap on a temporary tank to test things before I finish the fuel tank.