factory

I'm certainly doing well to solve/identify some of the mystery parts & tools. There are still a few more to solve though. Thanks to Andrew for adding the pictures as the link will become dead a few months after they are sold. I've edited the pictures and it looks like there is an adaptor plate between the carb & the induction housing flange, I would imagine it has some countersunk screws hidden inside. Both the adaptor plate and air filter plate look like they could be made without too much trouble, if Webhead hasn't got spares of either of them. There also appears to be an extra pipe fitting on the crankcase with the remains of the tubing & retaining spring. David

I've built up a good selection of UNC/UNF taps & dies over the years (for repairing my both collection of O&R engines and vintage HP test equipment), most of them were bought second-hand at reasonable prices from the stalls at steam & vintage shows. It can take quite a bit of searching though if they are mixed up in boxes, as they usually are. I have also found a few suitable screws (for the earlier O&R engines that use slotted screws) as well, usually on the ex military surplus stall. Webhead has helped with supplying the Fillister head Philips screws that are found on most O&R engines. The starter/blower housing screws are the most often to be missing, or damaged by people using the wrong type or size of screwdriver.. David

The rubber seal is a not just a flat piece, it's attached through the diaphragm arm and seems to have a little movement to allow it to seal properly. Not sure how you could make one or work out the correct material to use. Here are a couple of pictures of a diaphragm arm with the rubber seal. David

Finally found an engine with the Tillotson carb, looks like it was intended to be used on the Groomer weed trimmer. http://www.ebay.com/itm/Vintage-OHLSSON-RICE-O-R-COMPACT-Gas-Engine-Pull-Start-/182606956279?rmvSB=true Unfortunately the seller has the ebay international communication block activated. David

That's not a silly question at all, there were a few different types of imperial thread commonly used in the UK in the past, but the O&R engines use American UNC & UNF threads which weren't used much over here (apart from some computer parts & connectors, some of which still use them). UNC/UNF is also known as ANC/ANF but sellers often only use the number or fraction and the number of threads per inch e.g. #10 x 32tpi. Below is a chart I use, created from several pages in an old reference book. All the threads apart from the spark-plug are either UNC or UNF, the spark-plug thread is metric. The starter/blower housing & carb mounting screws are both #6 x 32tpi UNC, these screws have a Fillister head. And the power output shaft (tapered version) is tapped #10 x 32tpi UNF, there is also a D shaped output shaft with no hole found on some engines. David Edit Here is a PDF of the thread chart, as the picture above has been automatically reduced in size by the forum software making it harder to read. UNC UNF Threads & Drill Sizes.pdf David

Here is an exploded parts diagram for the O&R carb (slotted needle version). David

That explains it then, I've seen the same freely available article (re-typed) being sold on ebay, full size plans are also available as well. Octura Models are still going, but they don't seem to have a website. The clear one-way valve was originally made from the same black rubber as the diaphragm, the rubber valves perish too and sometimes the valve part falls off. I don't know when they changed to making the valve from clear plastic, as they didn't change the part number for the newer part. Here is a diagram for the carb, I will add it to the carb repair thread too. David

That looks a nice clean engine, it probably hasn't had much or any use, which may explain why it's running with the original diaphragm. They tend to harden & crack after being exposed to fuel, it's rare to find an original that is OK. Those earlier style carbs are quite hard to find, I have a few O&R engines that may have had RC use in the past, often the governor vane is missing and the carb permanently modified for the RC servo. Google has scanned the entire archive of the US Popular Mechanics magazine. The article for building the White Heat V hydroplane by Tom Perzentka (of Octura Models) is in the June 1962 edition, available for free on google books here; https://books.google.co.uk/books?id=mtwDAAAAMBAJ&pg=PA124#v=onepage&q&f=false It's on pages 124 to 130, pages 186 to 188 and page 190. Seems that your scans slightly are different, is it from the Australian edition? David

You should be able to find gasket paper/card available in small amounts on ebay, I got a pack of various different thickness for a couple of pounds. Then choose the size closest to the original and cut a new one, don't forget the vent hole. I would have measured mine, but don't want to damage it as it won't come out easily. David

Someone probably didn't use a screwdriver of the correct size, seems to happen far too often judging by the amount of chewed up screw-heads I find. I too could only find the manufacturers manual for the standard type HU carb on the web. Here is a picture of the correct diagram, I'm now slightly puzzled why the one in the first post has an extra inlet, has someone swapped the cover? David

Looks like your Chicken Power is fitted with a carb primer button, I also noticed it was made under the Advanced Engine Products Inc name (which is on the box, instructions & the engine blower housing), so it probably will have the rubber seal on the diaphragm arm. David

Here are some more pictures of my model 400 DC generator, which I'm currently working on. Both the commutator & carbon brushes show little wear, there is some corrosion the steel laminations on the armature, hopefully it will clean up OK. There is still some magnetism left in the field coils, some filings/swarf can be seen on the ends of the coil blocks. Not sure how I can easily flatten the card on this one as it won't fit past the fan, it may have to be done in situ. David

I will have a look tomorrow, but I'm pretty sure it's made from thin gasket paper. David

The fuel/gas cap usually has a thin gasket inside, maybe it's missing or damaged, the cap for the Tiny Tiger base tank also has a vent hole, I have a Champ generator where the cap has been modified to allow the vent to be open or sealed. David

The service manual gives engine model numbers 13A-181, 13B-328, 13B-340, 13B-341 & 13B-406 as being used for the Chicken Power, the first has the ball bearing and the last has the rubber seal (spares were only available as part of a repair kit), I haven't got info for the others. I have a few later engines without the carb primer button, any engine with a gravity feed fuel tank doesn't need the primer button, however two of the later engines I have with no primer button have a base tank. I had questioned this in the past and it was suggested they should have a primer button, the later parts diagrams don't help as they show both types in the exploded diagram. The parts lists for both the models 13A-181 & 13B-406 give the spark-plug fitted as type CJ14. David

Well I've failed to find any pictures of any model 13B engines fitted with this carb, my service manual folder doesn't have it either, I guess it must have been available towards to end of production of these engines from Advanced Engine Products as in the book in the previous post mentioned. I only have a couple of engines (including a Drillgine) in my collection with the AEP name instead of O&R. The next question is does it need any extra parts to fit to a 13B? I don't suppose you could save me one for when I next need some spares? Which could be soon as I have just run out of the early style bearings with the plastic housings. David

Didn't take too long to figure out. It's mentioned in the book "Small Air-Cooled Engines" 16th edition from Intertec Publishing, I have had two different editions of this book shipped over here, the 16th edition covers the Compact I, II, II, 13A, 13B & 20A models of O&R/Advanced Engine Products engines. Your mystery carb is a Tillotson model HU and it was apparently fitted to late production model 13B engines for constant speed operation, it is pre-calibrated for constant speed operation only and has no fuel/speed adjustments or throttle, the primer button is is used for starting enrichment to allow extra fuel flow. Also no air vane governor is fitted. There is also an exploded diagram of the carb. I now just need to have a look for a strange 13B in my saved pictures. David

No complete engine or tool/kit would have been supplied without a spark-plug, someone has lost it. Looks like it would have had a Champion CJ8 or CJ14 fitted as it's the 14mm cylinder. The oil could have leaked from one of the seals or from the gearbox gasket, the only way to find out if they used a rubber seal or ball bearing in the carb would be to take it apart. David

Ouch. I wouldn't recommend trying to repair a flywheel with broken fins if the taper was OK, it would be completely out of balance. I have one here that someone has glued some bits of sheet aluminium to, it's scrap in my opinion. Also check the flywheel nut hasn't got stripped threads. David

If it's running why do you need another key & flywheel and what happened to for it to land on your foot? A flywheel shouldn't be to hard to find, but you may have to make a key as we mentioned before, if no one has a spare one. David

Very very rarely you come across an original diaphragm that isn't dried out or cracked, has yours been changed already or by the previous owner? As you have had it running before. Some carbs have a second small fuel filter in the bottom half of the carb, I had a similar problem with a Tiger that wouldn't run after being restored the previous year, it had the filter which was clogged preventing fuel getting to the carb. There was an O&R service bulletin recommending that the carb fuel filter should be removed as it caused too many problems, later carbs don't have the second fuel filter. I just cleaned the filter on mine, as the tank filter is missing and the in-line filter I bought still lets some dirt through. I should really replace the missing tank filter, I haven't yet tried removing the steel panel from this type of tank, but others on here have successfully removed them by heating around the panel to loosen the glue/sealant holding them together, you could probably fix your original larger tank if it was leaking from the seal around the panel. Also I had a closer look at the picture, are the two gaskets missing from between the carb assembly and the induction housing? That is the only other thing I can think of, as the screw holding the carb looks too long and I can't see the gaskets, you will get air drawn in if the gaskets are missing. David

The water-cooled cylinder with 10mm spark plug can be found on both the early ¾HP engines as well as the later 0.85HP & 1HP engines, the water-cooled cylinders don't usually turn up without an engine though. It was available from O&R in 1962 (part no. A-40-3) as well as Octura Models but doesn't appear on any other parts lists I have seen. Here are the specifications for the ¾HP, 0.85HP & 1HP engines, note the compression ratio & stroke is different depending on the engine rating, the first is from 1961 and the second is from 1966. I have also seen 14mm cylinders that are water-cooled, but they look like a modified version of the standard cylinder, these do appear in the UK occasionally (both 10mm & 14mm cylinders), but I have always wondered if they were modified by model makers/engineers as the water pipes are never in the same place and the starter/blower housing is often cut down. I even saw one with a hole in the starter/blower housing for a water pipe. I have not found any articles/information about this though, probably not helped as some magazines such as "Model Engineer" don't have a on-line archive. Here is a picture of one of these modified engines (not mine). David

That will be a Champion UY6 10mm spark plug, later engines with the 14mm spark plug used either a Champion CJ8 or Champion CJ14. You may find that the current production Champion spark plugs do not have a re-moveable terminal nut, the modern CJ8 spark plugs I bought are definitely not re-moveable, not sure about the others though as the new CJ14 I bought turned out to be new old stock made in Canada and I have never bought any new UY6 as they are expensive over here, I did buy a box of new old stock from the US though. The non re-moveable terminal nut is only a problem with earlier engines that don't use a HT lead with a spark plug cap. David

The original article for building the White Heat V hydroplane by Tom Perzentka (of Octura Models) in Popular Mechanics from June 1962 used a standard unmodified air cooled engine with the original magneto ignition. The full article including scaled down plans for building the White Heat V hydroplane is available for free on google books here; https://books.google.co.uk/books?id=mtwDAAAAMBAJ&pg=PA124#v=onepage&q&f=false It's on pages 124 to 130, pages 186 to 188 and page 190. The plans were originally also available in full size, Octura Models also sold the engine, mount and a kit of parts. The engine used (pictured below) is also one of the first 6000 produced by Ohlsson & Rice. David

Looks like the one from this thread: Hopefully both sections of the old disintegrating filter foam were removed as we didn't mention it in that thread, but it is in the linked carb repair tutorial thread. David