[vhgmcbuddy]

Hi Charlie, thanks for your reply, it was silly of me to miss the absence of a sump so it is obviously a two stroke do you have any idea of the type and where I might find some info about it ?

[vhgmcbuddy]

Found this maybe you’ve seen it already. There’s a few photos there too.
Practical Machinist.

https://www.practicalmachinist.com/vb/antique-machinery-and-history/ot-crawler-tractors-196276/index16.html

believe this to be an “Orolo” track unit, or a copy of one. “Roadless – The Story of Roadless Traction from Tracks to Tractors” by Stuart Gibbard has this to say about the “Orolo” track unit.

“One of Roadless‘s first and most commercially viable ventures was the introduction of the Orolo track units. Originally designed for the British Admiralty to transport a 6 in. naval gun over soft ground, the Orolo unit consisted of a self-contained bogie with rigid girder tracks running around two or three rollers. The track was designed to be self-locking so that it would form a predetermined radius to give it the same performance as an extremely large diameter wheel with very low rolling resistance.
The Orolo units were available in several different sizes, and could be used in place of the wheel in a variety of applications, including bullock and mule wagons for Africa, India and South America, log carriers and lifeboat carriages – and the Roadless drawing books even show details of an Excelsior washing machine so equipped in 1932, but for what purpose is not known.
When the Orolo unit was first conceived, a scaled-down version was tested on Philip Johnson‘s garden wheelbarrow. So successful was this unit, that Roadless decided to put the tracked wheelbarrow into production. A couple of hundred were made towards the end of 1927, and it became a popular addition to the company‘s early product line. At the other end of the scale were the D8 Oro1o track units, introduced in 1929 and capable of carrying 12 tons per pair. The company eventually built units during the Second World War which would carry 20 tons on each track-bogie. The Orolo track units remained in production until well into the 1960s.”

I can’t help but notice that at least two of the gentlemen at the John Allen & Sons (Oxford) Ltd. stand at the Royal Show are wearing spats.

The pub model(?)…

…and the export model(?). (Manufactured in 1929 by Khasia Sillimanite Company in India).

You can see one of the original patent documents for this type of track <here>.

G2 Orolo brought out in 1930 with rubber jointed tracks.

[vhgmcbuddy]

Do you have photos. I dont know anything about it but I’d like to see it.

John

[vhgmcbuddy]

Excellent idea…I’ll try that as soon as I can get another pair of hands on the crank.

[vhgmcbuddy]

The split pin is there to stop the rings turning in the groove. As a 2 stroke it is important that the ring gap does not line up with any of the ports in the cylinder bore, this could happen if the rings did not have the split pin to prevent then moving.

Seems a fairly crude way of achieving the desired result. Is the split pin an original feature or some “Bush mechanic’s” bodge after a happening of some sort?
Even Villiers have a more elegant way of doing it.

Attachments:

1. 

[vhgmcbuddy]

Try removing the fuel injector and reconnect it outside the engine,crank the engine with various throttle settings and watch the mist see what happens when you shut the throttle down, sounds as if the governor fuel rack link may be set wrongly. Good luck.

[vhgmcbuddy]

Thanks, that is a valid point. Being two stroke, it uses the crankcase pressure as part of the cycle and maybe I should double check the flapper valve. There must also be a link between the rear crank chamber and the front gearpump chamber for oil movement.

I have double checked the fuel pump ‘spill angle’ It was at 25 degrees BTDC, now adjusted to the required 30 degrees BTDC.
Tappet adjusted to correct 6 thou. Decompression ‘fork’ needed a tweak and now works as required with the new tapped adjustment.

Will try for another start this eve and see what we can find. J.

[vhgmcbuddy]

An uninformed guess, check for air leaks.

[vhgmcbuddy]

John E-W

Every day’s a school day. What I thought was a split pin is the bottom piston ring divider. I attach a photo.

John

Attachments:

1. 

[vhgmcbuddy]

To remove gudgeon pin (wristpin) remove the clips part number 10297, see parts manual plate 2 for illustration.

If it’s an alloy piston, with clips removed, suspend it in a pan of boiling water for five minutes and it will probably expand enough to allow the pin to be just pushed out. Failing that make a tool similar to this to push it out. No apologies for its rather crude appearance as I made it in about 1960 when playing with Lambretta scooters. Amazing how many pins it’s pushed out on a variety of engines since then.

Attachments:

1. 

[vhgmcbuddy]

Wristpin

No I think you’re getting it wrong. Read it in this photo….not the one you added

Attachments:

1. 

[vhgmcbuddy]

Ah, looks like we are talking about a different product, but even so the blurb for your tin seems to be saying that it’s for “penetrating wood” preservation, not as in penetrating rusted / frozen metal components. However, if it works for you, so be it.

Attachments:

1. 

[vhgmcbuddy]

Hi Wristpin

Attached is photo of the can of Owatrol oil.
It’s definitely better than WD40 anyway.

Attachments:

1. 

[vhgmcbuddy]

#38778

aquila787

Participant
I bought a can of owatrol oil yesterday. Supposed to be good. I’ll try it and see.

No one commented when the above was posted, but……
Owatrol is a paint additive or patina preservative, not a penetrating oil.
Plus Gas is probably the best proprietory penetrant – preferably in a can and not aerosol. Diesel of either colour or Kero is very good, particularly if the parts can be dropped into a bucket of it and left for a few days.
Our transatlantic cousins seem to favour a home brew of Automatic Transmission Fluid and Acetone.

[vhgmcbuddy]

Thanks Charlie. Any clues on how to age my Rotavator?

[Author]

Posts