LH Colt restoration

[Paul_Linden]

At some point in a bike restoration there comes the time where you have to clean, prepare and paint lots of small pieces. That time has come. Here's a selection of brackets, trays, carriers etc that need the treatment. This sort activity seems to eat the time up.

And here's the headlamp shell. Ghastly.

Halfway there, same brackets as before but primed. I promise not to post any more pics of dirty brackets.

[Paul_Linden]

The 1954 Colt was not fitted with an oil pipe to the head, but from 1955 onwards Colts were fitted with one. Obviously the oil mist was insufficient to keep the valve gear lubricated and Ariel fixed it by adding an oil feed to the head. The olier was also made available as a retro fit kit. (BSA did the same on their C11s in the same year.)
I know this won't be a high mileage bike but it seems prudent to fit the oil feed kit while it's all dismantled. I picked up a later trunnion, which has a groove down the middle for the oil to flow down to the rockers, and fitted it to the head. With hindsight I'm sure it's possible to adapt a trunnion by cutting a groove in it. Old and new trunnions below.

Some GOOD NEWS. The cases came back from the engineer today. Of the three bushes only the main one needed replacing, the other two were within the limits of wear.
The new shiny bush stands out here.

Some BAD NEWS. The flywheel has four cracks in it radiating out from the hole for the big end pin. You can just about make out three of them at 1, 6 and 8 o'clock. The engineer who broke the bad news to me told me a great story of a friend of his who raced Velocettes in the 1950's. One day his friend was in a race and following an Ariel. The Ariel's iron flywheel broke into pieces, which flew out in every direction at high speed. One piece of flywheel punched through the Velocette's engine and destroyed it. From that day the racer never followed a bike with iron flywheels!
The other strange thing is that where the shaft of the crank meets the flywheel looks like it underwent an amateur repair at some time.

[simon.holyfield]

Really enjoying your story.

Where are you planning on getting your tank plated?

[Eero.Korhonen]

Yes me too, it is good that someone is making big job with pics and text.
Br, Eero

[Paul_Linden]

Simon - the chrome plating is being done by Doug Taylor Ltd, which is near Bristol. They did a good job on the Colt brake arms for me last year so when it came to the petrol tank I was happy for them to do it. The tank will be ready next week. They had a stand at the Shepton Mallet Auto Jumble last year, so they know the bike market.

Thanks for the feedback - I hope the technical info is useful, and I'll try to keep it entertaining. Spoiler alert - I found a spare crank, so that issue is now resolved.

[Knud.Degnbol]

Some BAD NEWS. The flywheel has four cracks in it radiating out from the hole for the big end pin. You can just about make out three of them at 1, 6 and 8 o'clock.

In 1959 I saved a similar cracked crank by turning the outside diameter down 5 mm, and then shrinking a steelring around it.
Knud

[Paul_Linden]

Hi Knud, that is a great fix! That sounds similar to how iron rims are fitted on to cartwheels.

Luckily I had a worn out crank in the garage, so that was sent to the engineers to have the new con rod and big end fitted. It came back looking like this:

Next was the replacement oil seal for the drive side of the crankcase.

[Paul_Linden]

So now we can start assembling!
For some reason in this picture the very thin smear of gasket goo looks like strawberry jam that's been applied with a spoon. Remembered to oil the bearing and bushes.

Cases together and bolted up.

and dropping in the breather ring, holes closest to the crank.

[Paul_Linden]

The engine stand took me half a day to knock up, but its one of those things that when you have one you wonder how you ever managed without.

The first part to go back in to the case is the oil pump, but it needs to be inspected. Remember this stood unused in the bike for 10-15 years and for the last year has been soaking in oil. It was too stiff to turn by hand but pliers would turn it, so not seized, but in need of some remedial work to get it to run more smoothly and free. The mazak metal casting was lightly bubbled on the surface, but underneath that it was solid.

Here is the oil pump stripped down. Top row from left to right are; the lower geared wheels; the body of the pump showing the lower chamber; the upper gear wheels; and the inside surface of the top plate of the pump. The bottom row is the inside of the bottom plate and the two bolts which hold it all together. After cleaning out some black goo I put it together, and although it was a little better - it could now just be turned by hand - it was still a long way from usable. To free it up some more I tested the pairs of gears individually and found that the top pair were the problem. A small spot of fine valve grinding paste, and a few minutes with an electric drill worked out the stiffness. After a thorough cleaning and oiling it moved completely freely - it felt like winding a swiss watch.
You might see some yellow marks on the toothed wheels - these were to allow the gears to be meshed against the same teeth when the pump was re-assembled.

[pete.collings]

I can understand the concern about the oil pump appearing too stiff to turn easily, but this may well be the design of the pump. In the Huntmaster/A10 oil pump, a good pump should not turn by hand, but be able to turn under firm pressure.
As the Colt is a deritivite of a BSA single, I think the same logic may apply.
If you have the pump too free, it will just wet sump easier, not a problem if you are using the bike regularly, but needs consideration if it is laid up (eg. over winter).

I have just been dismantling and checking over some FH/A10 oil pumps, the thing to look for are grooves in the body where a bit of something hard has passed through the pump. Any slight wear on the mating faces can be eased down on a surface plate with fine emery paper. I just check that everything turns freely after oiling but before reassemby, even if it needs a bit of effort to make it turn. The more clearance, the more opportunity for oil to leak past the pump. I rarely find the gears in a pump worn, there is more likely to be a problem if the pump has been stored badly so that water can get in and corrode the gears.