factory

I should be able to help, is the coil open circuit or just need the perished rubber wires sleeving? I'm fairly certain the vertical fuel tank has the same dimensions as the horizontal versions (oil tank on this tool). The cylinder gaskets will probably leak if re-used, if you need to replace the shafts seals the only option is to use O-rings of the appropriate size. If you strip the engine down it's a good idea to use a large tray to catch any bearing rollers that may escape. Have you done anything with the gearbox, they originally used oil which either dried out or leaked out, they eventually changed to using grease. David

Just a note, the alloy handle used on these (can't see it in the picture) is a weak point , the thin section where it attaches didn't survive shipping on mine. David

I'm not sure about that Alkylate premix stuff, there isn't enough oil in it for my liking, also it uses synthetic oil. But they do have ethanol free fuel on it's own, which I could mix with the Stihl mineral oil at 32:1. David

Welcome Ray, @CNew has new laser cut carb diaphragms, if you haven't already seen it check out the carb rebuild thread at the top of the O&R section. David

It's all pure speculation unless you have pictures showing both the engine type & the model number (61MX3 ?) on the pump and several examples turn up to prove it's not been re-painted. The three rather low-res pictures could be from many years ago, worthlesspoint harvests information from ePay listings, but usually only a couple of the pictures. The muffler certainly doesn't look correct for military use. As for the drone mention that is complete nonsense, people got confused with the large 4 cylinder McCulloch engine re-used in the early Bensen B-8M Gyrocopter (which can have an O&R engine used for the pre-rotator mechanism only). McCulloch made the drone engines. David

That's OK, if you do have any questions about the Tiny Tiger or these engines we will try & help. David

OK thanks for that picture, that is a Motorola 1N3491R diode rated at a maximum of 50 volts at 25 amps (date code week 49 of 1973), the 'R' in the part number indicates the polarity being anode to the case. This seems to have suitable ratings for the Tiny Tiger charger circuit and is the correct polarity. Note: This component is now obsolete, any for sale will either be new-old-stock or relabelled parts. Question is why they are with the Tiny Tigers, could it be possible they were returns that never got repaired? The manual does mention that they can get damaged if the battery is connected the wrong way round. David

@RobertDFW I'm a bit confused as to why you've quoted that post twice but haven't added a comment or question about it. David

The older engines used a ball bearing for the valve under the diaphragm arm, this would often get gummed up with stale gas/oil mix, they even recommend replacing the ball bearing instead of trying to clean it, but at least you can still get ball bearings as they are a standard part. The redesign uses the rubber seal on the diaphragm arm, these seem worse than the ball bearing as they no longer seal due to gas/oil mix and/or ageing badly. Unfortunately the seal was sold with the carb repair kits, same as the brass valve only being available in a new carb diaphragm bowl assembly, I can't help thinking one reason they did this was to generate more parts sales. The diaphragm arms with rubber seal are very difficult to find now, if it's bad you could replace the carb parts with the older versions (i.e. the carb bowl bottom half, a ball bearing & the older diaphragm arm). David P.S. Avoid using any gas that contains ethanol for the fuel mix for these engines, look for ethanol free (non-oxygenated) gas instead, it may be harder to find, but it should cause less problems with stale gas, swelling of rubber seals and corrosion from it attaching moisture.

Sadly I don't have a manual for the Estate 400 (only that low-res picture), but can help with pictures of some of the parts, including the trigger & cable, I have a few little trimmer head parts but none of the bigger pieces of the trimmer head. The stop/kill switch on most of the these engines has always been a simple shorting switch, either the brass strip type or a bought in switch, some of the chainsaws have a more complicated switch mechanism in the handle. David

Those are "press fit" diodes, they look similar to those used in the alternator part of the Tiny Tiger, which are used to rectify the AC generated from the alternator windings to supply the low voltage DC for battery charging. Do those have a part number on them? I've no idea why these diodes in my Tiny Tor have two different colors in the center, the picture also shows extra holes for the diodes to fit into, those are only used if one fails. Also available in "gold-plated rust" finish in my older Tiny Tiger. David

If anyone is interested there is an O&R with the Octura V-8 style exhaust on ePay at the moment; https://www.ebay.com/itm/383498494441 The same seller has another lot with some other parts including the correct Octura mount for the O&R, shame it's mixed in with a load of other parts; https://www.ebay.com/itm/383498470128 Note: these are only available for shipping to United States, Canada, Bahamas, Uruguay. David

There is also a possibility that it may use the later diaphragm arm with the rubber seal, instead of the ball bearing under the diaphragm arm. David

Maybe as we have both seen it before. I was looking through my saved pictures yesterday and came across this one; David

@Wallfish do you recognise anything about the early engine that CNew acquired? David

O&R listed the water-cooled cylinder in the 1962 parts diagram (part no. #A-40-3), I'm still looking for a decent one for my engine, but I do have the large exhaust and an Octura carb. And I should point out that there are other versions of the White Heat hydroplane for smaller engines than the Compact engine. David

The little brass part is a check valve, which is often stuck, here is a quote from @Wallfish in a thread last month about the same part; I've had one stuck too, at the time I had access to a large industrial ultrasonic cleaner which eventually cleaned the fuel/oil residue from it. The brass check valve is a press fit, I wouldn't recommend trying to remove it. David

I don't actually have much paperwork for anything to do with Octura except a leaflet from a UK reseller of them, that doesn't mention the special rotary valve. Does it look similar in design to the rotary valves used on the older O&R model plane engines (before the Compact engine existed)? David P.S. just ordered an Octura 1965 catalog featuring the O&R powered White Heat, will see if that has anything in it when it arrives from the US.

Those older coils always seem to have cracked (rubber) insulation on the wiring. Yes it needs the link tubing & gas line installing for the tank, plus an earlier air cleaner (they have fewer holes). David

What happened to the rest of the parts? I thought the lot included another boat mount & some other fittings. None of the three engines in the lot you bought are anywhere near new enough to go with that 1977 brochure, is the other one older? Also I've seen this engine before, it last sold in 2017. The rest of the parts & literature (dated 1971 on price list) look suspiciously like the parts from this lot (also sold in 2017), but the newer engine wasn't in the lot you just bought. David

Contact either @Wallfish or @CNew by private message & they should be able to supply some new laser cut carb diaphragms. What condition were the original ones in? The later Tiny Tiger engine may use the carb with the rubber pad attached to the diaphragm arm, we don't have a source for replacing these, but hopefully it will still be OK if it's not been run. If not we can advise alternate parts. David

I've now had a look for both types of starter dogs and taken some new pictures for comparison. The middle section of part no. A-139-2 measures approx 1/2" and the older part no. A-139 measures approx 9/16" (from the early Model L engine I have). And here are the two different types of starter dogs shown on an early flywheel (from a Petro Chug-A-Pump approx engine s/n #14000). And the same starter dogs shown on a slightly later flywheel (from a Tiny Tiger approx engine s/n #35000). If the information from the 1962 parts list is correct then the starter dog part no. A-139 was last used on engine no. #015997, after this they should be part no. A-139-2. If you need the later one (A139-2) then I have a couple of used spares, I don't remember thinking I would need many so didn't buy any spares from Webhead, as I said before I don't have any spare of the older ones (A-139). David

That one has an engine made in Feb 1974, which was the last year that these engines were branded as O&R, in December 1974 they started advertising under the new name of AEP (Advanced Engine Products Inc). I've not seen any videos that I can recommend, none of them seem to do any research into how to repair these engines beforehand, but then again you've got to remember they are mainly made for entertainment purposes only and aren't really tutorials. As well as the Tiny Tiger rebuild guide @Wallfish posted, there are others here for the carb & engine, also if you don't have the original manual for those Tiny Tigers I scanned mine & added it to the Manuals thread. David

I'm not at all surprised seats are advertised at silly prices, anything to do with vintage bikes seems to be really expensive these days. Those two Micro Power bikes I have pictures of sold for $1k+ and that was in 2015. David

These are the only other pictures I have showing the brake mechanism, the bike dynamo hides most of the mechanism, the unknown make mini-bike I bought uses a simple band brake on the front wheel. David