That is almost certainly a Universal Motor Company two stroke engine made in Derby, available in sizes of 1/2 & 3/4HP and thought to have been produced into the 1930's.
Please note the value depends on condition and is not necessarily the maximum quoted.
It's a Whitney Simplex gas engine made to the Bathe design, dates to around 1908 to 1910 and was made in London.
Can you take a picture of the underside of the cylinder so we can see if the valve gear is still there. The value without the valve gear would be somewhere in the region of £400 to £450, with the valve gear about £750, but this depends on the mechanical condition, which is difficult to assess from photographs.
There is a article on Bathe engines in the Stationary Engine Magazine, August & September 2016 issues.
Here is a nice picture of the ad from 1908, £5 in 1908 is around £500 today.
The engine in the first photo in post #1 is from the first one or two years of production, the brochure/price list from 1961 doesn't give a option for a vertical tank, only the standard, jumbo, or base tank seem to have been available.
Another Ohlsson tool I haven't seen complete before, remains of an Acme Engineering Co. powerhead. It's possibly for a tree trimmer, as the patent number on it relates to a tree trimming saw mechanism, the patent is a bit earlier than any O&R's though as its from 1953, patent document is linked below.
Unfortunately the serial number is missing from mine (should be on the missing cylinder plate/cooling baffle) so it's impossible to tell which is later, unless someone has one the same.
According to an O&R service bulletin the "cooling baffle is seldom, if ever, lost"
The service info I have gives a starter cord length of 44" for engines below S/N 099151 and 54" for those above 099151. The length changed as a different spring was used for later engines.
The later instructions for starter repair (newer type) that I posted in the linked thread below, says that the cord is looped to form a knot on the reel (see Fig 10) to prevent the cord being pulled from the anchor wire.
Here are some pictures of my Bridges Mini-Mota drill, the tank on mine must have leaked as someone has repaired it with solder. I wonder where all the chuck keys go, none of my O&R drills came with one.
There are plenty of Champion UY6 plugs on ebay.com , that's where I bought a NOS box full a few years ago, as it worked out cheaper than buying them over here at the time.
I've had many engines with missing or incorrectly fitted long reach plugs. some of these were fitted by unhelpful sellers before they shipped.
Yes the forum did seem to go off-line for a few minutes when I first tried to reply and the post didn't appear. I then went into the shed to check the size of the carb screw as it wasn't on my notepad list. The pictures were still there when I started the reply again though.
I didn't realise the plastic check valve was now available again, I will probably need some more when I use the last two spares I have, as the early ones seems to deteriorate in the same way as the diaphragms, I even had one check valve completely missing the flap section.
The side mounted needle valve is original as it's an earlier style carb, there should be a #10x32 screw (half inch long with lock washer) that is missing from yours.
Webhead on here sells replacement carb diaphragms, the originals have often gone hard & brittle, it's rare to find one that is still flexible.
Here are some pictures of the carb from my Petro Chug-A-Pump that I restored last year. Check that you have all the bits shown in the first picture, the small roller & ball bearing are often missing if someone has been in there before.
The starter spring can be repaired by heating the end section with a blowtorch and bending to the correct shape with a pair of round nose pliers, make sure that it goes back in the right way round when reassembling, as shown in the second picture below.
I bought one of these drills earlier this year, here is a scan I have done of the manual that came with it.
The condition isn't great, but manuals rarely seem to stay with any of the tools. Also there is no mention of Ohlsson & Rice anywhere in the manual, instead Bridges refer to the engine as the Mini-Mota.
I used a couple of pictures found online to send along with the carefully removed old decals for reproduction. Titch @ Machinery Decals has done it again! perfectly recreated decals to adorn both these machines....... Here they are wearing their new clothes! The Mustang's bar decal has proved a little more difficult, however it is being worked on!
Very nice restorations, I have a few in need of a repaint, also its good to know you can get the other decals too.
First one I've seen with the newer style recoil and housing. Curious about that expanded metal for a debris screen in the recoil too. Don't remember ever seeing that before either.
Definitely the only fairly complete one I've seen with the later starter, I do have the engine from one in my collection, it also has the mesh debris screen. Never seen one fitted to anything else though, must be something Turbair added.
My PC has Windows 10, I usually use Firefox for the web. This site is working OK with Firefox and the other two browsers (Internet Explorer & Edge) on my computer. If something goes wrong I usually try the other browsers to see if they work or if the problem is somewhere else.
As Karl says, posting a screen capture and what you are using (the operating system and browser) to access this site may help with identifying the problem.
Here are some pictures of my Orline Challenger Mark IID chainsaw, it has the larger model 20A engine, with a different (early?) starter housing to other model 20A engines I've seen.
I had intended to take some better pictures, but started work to find out why the fuel line was missing, after looking at the carb to identify the type for another forum member.
To get to the fuel outlet on the tank requires removing the engine from the saw frame, unfortunately I'm currently waiting for a socket to arrive to remove the last part preventing engine removal, the compression release valve. Everything else has either been removed or loosened ready.
I also found the missing (when bought) carb choke lever screw stuck to the flywheel magnet!
I managed to obtain maintenance manuals for both the model 20A engine and this chainsaw, they have been scanned & turned into pdf files and added to the manuals thread.
They are definitely a lot rarer, I certainly couldn't find pictures of any others on the web, although there were some on the old forum but I never saved a copy of them.
Here is the only other information I could find, from magazines scanned by google;
Mini stationary engine
in Stationary Gas Powered Machines
Posted
That is almost certainly a Universal Motor Company two stroke engine made in Derby, available in sizes of 1/2 & 3/4HP and thought to have been produced into the 1930's.
Please note the value depends on condition and is not necessarily the maximum quoted.
David