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Vintage Triumph motorcycle strip & rebuild. Part IV

Here is my 1934 250 Triumph L2/1 which I bought as a non-runner. It had compression and a spark and the carb seemed in good condition.

So welcome to the last section last video in the compilation of putting this 250 triumph back together this is the photograph that where we left the the the last flip and it shows the engine fitted into the frame a few things to do to get the thing ready the first thing i do is before you actually do any of the fitting of the magnet or anything else is to make sure

That these sprockets are lined up so you have the drive sprocket on the engine here and you have the pickup sprocket on the gearbox and that is absolutely drive sprocket to the rear wheel it’s important that the lined up and i use a steel straightedge to make sure they’re lined up correctly you can move the gearbox so you can move the engine i find it a little easier

To move the engine because they’ve got a little bit more flexibility the gearbox itself runs on this pin here and it it rotates like this to make sure you’ve got the right tension in the chain going to the back wheel that’s the adjuster for tensioning the rear chain it’s important that when you’re lining this up that when you’ve got it aligned like this and you’re

Happy that it’s straight that you go through the full range of movement on that sku to make sure that the the sprocket doesn’t move out of alignment as you start to tension it so that was the the the left-hand side of the engine the right-hand side of the engine and as you can see here i’ve put the the gears in i will take them out and i’ll show you why in a moment

But i just wanted to make sure that it all fitted or got all the push rods and everything sorted if i put the exhaust valve lifter cable in here that just may put that in to make sure that it actually stays attached and it doesn’t flop down and this is the handy pivot for the hand gear change and so it’s that’s the right hand side of the engine the next part is to

Fit the magneto and the alternator the magneto runs off the paper and it does this so it allows you to change the timing of the magneto and so therefore you have a a tapered section here there’s no key in it because you need to be up rotate the gear on it but it’s important that the tape was in good condition and the threads in good condition you can see you have

The threads a good condition and tape present and so the first thing that i’ve done here is to get the mating gear and it’s a taper on the inside of the gear here and it’s the taper on the outside of the shaft that i’ve got this grinding paste and basically i just rub the two together until i get a good matching taper between the two there’s no point in having

A perfect taper on one and a different taper on the other or a good paper on warning a dodgy shaft on the other side it’s important that both are in good condition because they do need to grip so it’s worthwhile putting the effort in to make sure that the those two mating surfaces are are smooth are aligned i’m not going to to bind with you when you tighten this

Nut or so make sure you take all the the grinding paste off before you put it all back together but what done now is i’ve put the the alternate that this alternate is a part at the top and the magneto’s at the bottom and that fits in an assembly that sits on that plate it is completely adjustable so you need to make sure that it’s properly aligned in this direction

And in this direction as well so you want to make sure it’s it’s straight and level in this direction but you want to make sure that it’s properly aligned to make sure that that gear is driving correctly on my shaft there’s no it’s only a simple strap that holds it together this is a brass strap by the side held together with a little set of nuts on there and then

This is the advanced cable that is going to go back up to the handlebar i put all the gears in here just to make sure it’s all properly aligned i’m going to take that off to ghost intersect magneto but you can see how it’s all set up this can be adjusted afterwards so i wouldn’t worry too much about it but you mustn’t forget to get that aligned because it will

Cause you issues on your timing it will cause wine in the gears if it’s not quite set up right and ultimately it’ll cause you wear on your memory directly in the end of the day if it’s not properly aligned so this is the left hand side you can see here i fitted refitted in the drive shaft with a spring coast drive i’ve got the chain right in everything so that’s

Now all settings and they sustain your change it’s going to work well and what i’ve done is i know that wound magneto roman until such time as the contact breakers just a to open and have made a little mark so i know that the angle of that contact breaker arm is just when the contacts are starting to open and so i’ve made a mental note that that is the position

Of that that the contact arm needs to be in and when we just passcode top dead center so therefore i can narrow i know that magneto position with the rest of the engine this is the advanced line here and what i’ve done is i’ve made sure that that is a maximum advance and so therefore i’m in a position where i can then adjust this afterwards because of the the

Adjustment system will allow me to then move backwards from that position but as i say that is i used just a standard cigarette paper test where you basically rotate the put a piece of paper in between the two contacts and they rotate the magneto around until it’s just open you can pull the contact the paper out and that’s when you know that the contacts are just

Coming apart and that is the angle at which that happens on the other side of the engine you have these two these are the camshafts and this these are basically sitting the simple bushes in the housing the engine housing and they also sit in bushes in the outer

Transcribed from video
Vintage Triumph motorcycle strip & rebuild. Part IV By Alder Marsh