Magneto refurb...

 Quite a while ago, I refurbished the magneto drive (K2F) but like the rest of the bike, I am dubious as to how well it was done, so another strip down was done - you guessed it - a few bits missing and the end float was wrong. New bits are now ordered and I await their delivery. One thing that is not available at the moment is a points set (brass plate variety) but I have a spare. I did manage to get a decent spark out of it, however!! 

And it's - off we go!!

Well, it's been a while but I have now progressed to getting the workshop mainly sorted and now I'm turning my attentions to the 3T.

When we moved, the gearbox was behaving strangely and the kickstart didn't seem to work. When the bike was put up onto my lift, I then found I could not even turn the bike over, so I have decided to start again and dismantle the gearbox. (I may even do the same to the engine!!)

When I eventually got the cover plate off, the kickstart spring was broken and it was not engaging in gears.

I think that the box was not indexing correctly. Once dismantled, I noticed that one camplate roller was very rough and if looked like the index was wrong. In fact the fork selector and roller were blued and very rough.....a spare to the rescue again!

The photo below shows the mounting lugs for the speedo drive. There is a gear above the sprocket (hidden) that drives the speedo.

Photo below shows the use of a vertical bar in the vice to support the gearbox - much better than trying to use blocks of wood etc.

These are the components for the kickstart ratchet - Somewhere in the garage is the washer on the right which decided to fly off the bench!! Good job I had a spare.

The camplate seems to have been using a pointed plunger. The older ones are more like a chisel point. I will use that type - see photo below.

Now the gearbox is back together and the indexing seems to be working much better with all gears being selected correctly. A new kickstart spring has also been installed. I will put gasket sealant on the mating faces and then it is ready to go back into the bike.

Still not finished.....

I still haven't finished the bike.
We are now in the throws of moving house and once my new workshop has been sorted it will be back to the rebuild again!! Watch this space......

Seat frame mock up and test

I never had a seat with the bike and it has proved quite difficult to get any sensible answers relating to the seat and fixing. It would appear that the nearest is the Trophy or T90 style seat and I managed to get some photos of a seat on the bike together with a couple of other 3T's over the last few months.
The salient information is that the spring centres are 8" apart. Armed with this I bought a Wassell copy seat (Indian) and set about modifying it.

The frame requires the removal of the lower rear underneath bar.

Brackets to mount the springs are 1" wide and 1.5" x 1" angle (about 3mm thick)

The seat fits fairly well now and I shall make the brackets for the springs and rivet on. When it is finished, I will post a photo before fitting the cover.

Photos of current progress - Tinware trial fit before painting....

Not much to say about this. I am still unsure as to how the toolbox fits to the frame - any suggestions?

The bits of blue masking tape are reminders of holes to be welded up etc.

There are a few queries on how the front mudguard mounts....

So, its taking shape.....

Engine build up etc

For convenience, I decided to choose the +10 barrels and pistons. These barrels were not worn and so I decided to hone them, and fit new +10 rings to the existing pistons.

You can probsably just make out the 010 on the upper face of the barrels - signifying that they are +0.010" oversize





The piston rings were fitted to the pistons and then the pistons fitted to the con rods. Nothing very difficult there! The cam followers were held in place with tie-wraps and the piston rings compressed down to enable fitting into the barrels using jubilee clips.



You will spot that in the above photo the casings have studs for the barrel and below they have changed to bolts. I forgot to check for this as I was selcting barrels and I also wanted to use the re-plated bolts.



The studs were removed and the bolts tested for fit in the casings. The barrels were then sprayed with spherex high temp paint (see head below) and fitted to the casings.



Next, a few trial fits of the head and working out how the engine stay fits to the head.





I had new valves to fit and the rockers, arms, spring spacers and wahsers were all cleaned up. The valves were lapped in and I even tried blowing down an exhaust outlet to test the fit - air tight with no springs! The only problem was that when I tried to fit the rockers, the inles valve seemed wrong. It transpired they were about 5mm tool long!! So I managed to seach through the boxes of bits and find two decent inet valves. New springs were fitted and all seemed OK fitted together.




It is quite fiddly fitting the rocker shafts with all the various washers etc but if you push the rocker gradually through and use tweezers to locate the various washers at the various stages then it all fits OK.
The head was then degreased, most of the rust removed and then masked up ready to be sprayed with spherex high temp paint.



Fitting the head was not so easy.....

Various stainless parts

It becomes a bit obsessive but once the decision to start using Stainless steel parts  I want to make sure they all are (within reason). This picture is an example of one I remade.

It is one of the domed gearbox nuts.