Montesa Cota 247

[oldaz]

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.

[fourex]

Oldaz and Motosolex, you pair have me confused.  Are you both comparing apples with apples, so to speak ?  Oldaz has a 1975 UKR 247 with 168mm (approx) between centre of fork tubes and Motosolex has an early 1980's 349 which possibly has the narrower fork tube spacing which appeared on some models, but I can't remember which years or 348/349 models that was. There are so many variables between a '75 Cota and a '79/ '80's Cota 349 front end, that it's difficult to compare one against the other if you get my drift. I can confirm that the 349/4 Cota returned to the wider 168mm fork spacing but I'm sure at some point previously Montesa experimented with narrower spacings which in turn would have altered hub /spacer/ speedo drive dimensions.

PS: Not to mention the very brittle conical hubs that the 349/4 and 350 wore.

Edited February 27, 2018 by fourex
PS added.

[feetupfun]

From the bikes I've seen, the second model 349 (the white tank model) was the first 51M to have the fork tubes close together.

Edited February 27, 2018 by feetupfun

[oldaz]

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.

Edited February 27, 2018 by oldaz
More details

[motosolex]

Thank you fellows. Will keep looking into the matter and play around more with it in a few days. If in the meanwhile you happen to come across and info please pass it along. 

 

[oldaz]

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.

[motosolex]

Nice work. Keep us posted. 

[motosolex]

On 2/20/2018 at 12:13 AM, oldaz said:

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.

What sort of refurbish work on pushers did you do?

thanks. 

[oldaz]

1 hour ago, motosolex said:

What sort of refurbish work on pushers did you do?

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.

[motosolex]

26 minutes ago, oldaz said:

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.

Superb. Nice to have a lathe. I need to look through the bin of parts to see how our pushers etc.  are. Did you happen to get some PCs? Thanks for the info. 

Edited March 1, 2018 by motosolex

[oldaz]

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.

[motosolex]

Greetings Oldaz. 

Here is the 349 set up. Maybe this will help. Keep us posted on what you do to arm the spring. We will need to do the same soon we hope  

Perhaps posting a picture will help solve the issue. 

 

[motosolex]

Here’s a note from a rare guide on assembly of the 349 engine. 

Can anyone out there please paraphrase step no.11?

[oldaz]

On 05/03/2018 at 12:02 PM, motosolex said:

Here is the 349 set up. Maybe this will help. Keep us posted on what you do to arm the spring. We will need to do the same soon we hope

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?

 

[turbofurball]

That's how my 349 is, it was a bit of a struggle to get it on but feels like the right amount of pressure on the bike (I had a new spring with a new kickstart lever from InMotion, the old one was pretty sloppy in comparison)