Restoration of a Maytag model 92

The motor is a Maytag Multi Motor Model 92 and is a 3/4 h.p., 2 cycle motor with a 2 1/2" bore and a 2" stroke. The Bosch magneto was introduced on the model 92 Multi-Motor. The petrol (gas) tank is type #S-231. I've dated the engine using the date list from Maytag Multi-Motor Engines as 1930. The motor is serial number 440,578.

Come March 2002 and the first break I've had from my job for a while now so I set about taking the little beast apart. Unfortunately at some time during the motors life water got into the fuel tank and into the crank case. The crank shaft is frozen into its "bearings" and the piston is stuck firmly in the bore. Fortunately the piston is at BDC so is probably only rusted around the end of the bore. The inside of the bore seems ok from what I can tell peering in through the spark plug hole! At this time I've disassembled most of the motor and am awaiting the advice of a knowledgeable Maytag Man Ron (Maytag Twin) Carroll for a couple of points before I proceed. The photos below show the current sad state of affairs...

Day One

I knew the piston was stuck so I took the head bolts out then the bolts securing the "carbeuretor" (being generous here!). I removed the carbeuretor so I could inspect the crank case and fuel tank. The tank is cast into the base of the motor. Overall the motor looks in reasonable shape outside considering it is 72 years old!

and this is what I saw when I looked inside - yuck! At some time during the motors life it has gotten very wet inside - in fact the fuel tank and crank case were full of water mixed with fuel.

Next off was the flywheel (this is really easy on a maytag... undo a nut and one whack with a block of wood and there it was in my hand (the flywheel you git!).

The magneto looks to be in good shape. This assembly was next off. Fred Maytag tried a modern trick here - a screw which looks like it "obviously" has to be undone to remove - not so! Anyway it was off in short order.

I removed the cotter (split) pins securing the conrod journal nuts and removed the back half of the journal, once the back was off the piston and head fell off the front of the engine under their own weight (this is why I took the head bolts off earlier). The journals are (surprisingly) perfect. The piston is well and truly stuck in the bore. A little experimental whacking with the wood block got nowhere. I tried misting alcohol based starting fluid into the bore through the spark plug hole and dropping in a water proof "dynamite" fire cracker then screwing in the plug - pop - but nothing doing. If the piston had only been a little stuck this would have worked - honest!

This photo shows the extent of the rust in the crank case - pretty ugly, but survivable.

This is the (almost) stripped down frame. Here is a question for you Maytag nuts (you must be, you're reading this, yes you, the guy hiding and fidgiting over there mumbling...) Does the shaft onto which the fly wheel mounts turn within the shaft circled in yellow, or do they both turn as one. If the former, then this engine may not be saveable without machining which I am not equipped to do - the project will end here if this is the case as there is rust at both ends indicating it probably goes all the way through. Randall Semeiks provided the first answer to this in my mailbox: In that one picture, the shaft circled in yellow does not turn. It's what the mag plate mounts onto. One long bearing is inside it, and the shaft inside turns. Because of that, even if it's stuck, it should be easy to drive out with a hammer. I would unbolt that plate and take the whole assembly off and try tapping it (on the end that the flywheel nut screws on) and it should pop out the other side. If not you can always find another crankshaft and that side plate (for lack of a better term). They appear on eBay from time to time.

Always sad to see a motor like this... just a box-o-bits. Later tonight I'll turn the piston and head the other way up and squirt in some more mouse milk penetrating oil (really evil, will self ignite at room temperature!).

Is this just a split pin that can be driven out? I did not have anything suitable tonight and it was getting dark so I stopped work here. Again Randall provided the answer here too: In that other pic, the pin you're pointing to can indeed be driven out. Just take a small drift or other metal item and drive it out from that side (the hole is tapered, it'll only come out one way).

Day Two

This is the inside of the tank showing the water and other crap sloshing around inside. The good news is that this is a cast tank so there should not be any little drip pin holes opening up because of the water exposure.

The waxes and plastics came out of the fuel when the water got in and made these little stalecmites (spel?) hanging from the lid (or is it stalectites which hang? - never can rememeber!)

I took apart the carb while waiting for the penetrating oil to work on the crank. Surprisingly after cleaning it out it is in really good condition. None of its various pipes or fixtures were blocked in the slightest. I dont think the body is iron, it may be aluminium. The carb parts seem to all be made of brass.

This is the check valve and inlet assembly. All spotless! This was submerged in the crap in the tank so I was expected bad condition, but no, it is fine.

These are all the various parts of the carb, all in good condition, even the needle valve is sharp and true. And just for Dave Rotigel - look there is an air intake flutter valve just like your Galloway... maybe this is an engine afterall.

I followed Randall's advice and drove the crank out with a (really big) hammer and it worked fine. The crank is actually in pretty good condition. The journals are dirty but not scored or pitted. They'll be fine after a bit of cleaning with wet-n-dry emery paper.

This is the bearing surface which goes through the long journal the magneto attaches to. Interestingly it too is in reasonable condition except in the central oil chamber within the journal which had water in it. It will clean up ok and be useable.

I cleaned up the crank case a bit and it looks much better now with most of the bubbled rust gone. Still needs a treatment of something to stop the rust but it'll be ok.

The surface of this journal is in great condition espectially considering it had a rusty crank driven through it with a hammer!

Ditto... this journal is also in good condtion except for the central oil reservoir which will require scraping and some kind of rust treatment. The central part does not appear to be journal metal, but is the bare iron. The crank was driven through here to get it out. Did not do any appreciable damage and seems to be in pretty good shape. I still don't understand how enough oil gets in here to stop it all over heating and seizing, but obviously it does. I can see one obvious oil line into the center of the journal, but no indication of how the oil gets into it. Perhaps the internal crank case pressure forces oil/fuel mixture into here?

Tonight we're having a bbq dinner, so after I've cooked I'll stoke in some more heat beads and drop the cylinder head with its suck piston in and let it heat up. Following the advice of L. Phillips I'll drop it into a bucket of water once it is red hot and "the piston will come right out". It'll be nice it it this easy! Once the piston is out, cleaning up has to start then re-assembly. I'm going to need some help with timing the little beastie to get it going again once everything is back together - yeah I should have marked the flywheel vs. crank location, but I didn't and now I'm screwed - live and learn (ok, I did not learn, I've done it before). At least there are no bloody valves to set! So far I have to say that this little motor is pretty well designed, everything is simple and nothing has been required outside my tool bucket (ie. no shop tools) so it was within the realm of the average farmer to strip this motor down for overhaul just like I'm doing.

Day Three

To get the piston out I tried various things, then settled on repeating heating and quenching (twice) with one last heating to dry. This is the "furance" I heated the head and piston in. It is the BBQ starter tube. After a BBQ dinner I put the hot coals in the bottom, dropped in the head and piston then filled up the rest with new heat beads.

Heated to a glowing red in the furnace.

This is just before quenching in a bucket of water. Don't do this with a big casting - you'll break it - let it cool gradually by itself in the open air sitting on wood or dirt.

This is the final heating with water inside the head. The idea is to force the piston out. Again, don't try this with a big casting. Remember that the casting could explode. The water boils becoming steam which expands to 2700 times its original volume. In my case it did not do what I expected (force the piston out), but it had a good effect, as the water cooled it sucked the piston in. This broke the rust seal just as effectively as the other way around! After the piston moved I removed the spark plug and allowed the still warm casting to dry thoroughly.

Day Four

The maytag presents a particular difficulty to removing a stubborn piston - it is only accessible from one end. Normally I'd just put in a block of wood and pound on it with a sledge hammer. Cannot do that here! Instead I thought of a piston crane. The white "string" is plastic coated multi strand wire rope. I just wrapped this around and around the gudgeon and the metal of the "crane" and tied knots in it. By turning the nuts, the metal is forced away from the piston putting incredible pressure on the piston to move. I made the wire rope tight to the point where it would "tune" if picked and left it over night.

Day Five

The next day I kept turning until the piston moved. After each couple of turns peen the casting to relieve pressure and break any hold the crud in the bore has on the piston.

I found I could only get so far while removing the piston with the "crane" before the bolts started to seriously bend compressing the threads and locking the nuts. My next trick was to remove the wire rope and tie it to the gudgeon. Then I took it outside and tied it to our balcony railing and dropped it off. First dropped shocked the piston right out with the casting landing on the sandy dirt below. I've never seen anyone try this method before, but it certainly worked great - kinda like pulling a tooth.

The piston is in great shape, just needs cleaning. The rings were stuck firm. I've gotten them off (breaking one of them in the process) and started to clean out the grooves. Anyone know where to get a Maytag ring?

Now looking at the piston, and looking at this bore you have to wonder why the hell it was stuck in there. Just about no rust and very little crud on the bore. I'll clean this up with diesel and give it a slight hone and all should be well.

The engine is all in bits now. I have to finish cleaning up the fuel tank and crank case before coating both with automotive engine paint inside. I'll try and find somewhere to do bead blasting around here for a reasonable fee. Since there is plenty of paint on it Molasses is out of the question as the metal has to be clean for that to work. At least Berkeleyites could not object to molasses soaking - life does not come much more organic than that!

Cleaning day!

To describe my method in general terms... I scrape off all the grease, dirt, and crud with the brushes, screw driver, etc. then douse all the parts in the foaming degreaser. I like foaming cleaners that smell of diesel - they just seem to do a better job. Once the parts have soaked for the recommended time (15 to 30 minutes on the cleaner I used). I brush them again and then hose them off. This usually leaves you with reasonably clean parts, but not clean enough to paint. Next I get a bucket big enough for the parts and make a really strong mix of the cleaner (most bulk all purpose cleaners are good enough) and very hot water. Soak the parts in this mixture for about 15 minutes, then take each one out and go over it with the Scotch Brite scouring pads. Dip and scrub. Dip and scrube. Dip and scrub. Once the parts are clean, I refill the bucket with just hot water. The parts are rinsed in the hot water and left to soak until they too get warm. I make the parts warm as it helps the paint cure.

Once the parts come out of the hot water, they are left to dry (this happens quickly because they're hot). Once the parts are dry and have cooled to about 20 celcius (about 70F) I spray each one with a light paint coat. If I'm not ready to paint, or the part will not be painted then I give it a light coating of light oil to stop rust forming (note you have to wash this off before painting later!!).

This is the carb, remember what it looked like? After the degreaser and hot water cleaning everything is clean in and out - all working and no more crud. All the passages are free as checked by blowing air through them.

This is the crank - while there is some pitting and some stains which I have not been able to remove, it is reasonably smooth and with the light duty that this engine will do should not matter. If this engine was going to do real work, I'd be forced to get the crank machined and redo the journals to match.

All that rust and crud is now gone from the crank case and it cleaned up pretty well. To my surprise all that terrible silver paint came off during the cleaning process (ok, so the wire brush helped!).

These are some of the other parts which have all come up pretty well. Ready to paint.

This is the piston all cleaned up and ready to go. The cable ties are holding the new rings tight ready for insertion into the bore. The cable ties keep the rings compressed, as each ring is pushed into the bore, the tie is pushed back. Once the ring is part way in, I cut the tie and move onto the next ring.

This gives you an idea of what I was up against. This is the cleaner hard at work on the crap in the tank.

At this point I've just about finished cleaning up the ATIS Charity Auction Maytag and have started the painting process. When I got it, it was totally silver - an obvious (and poor) repaint - right over old paint, grease, etc.

So far each piece which has shown signs of green original paint has been painted green (and this is most of the engine). The only parts which show no signs of green, but have some original silver under the splashed on silver coat are the fly-wheel covers (but not the flywheel itself which has no paint at all), the magneto cover, and the kick pedal. So far, nothing too unusual. Does not match all of the "restored" engines I've seen, but I've confirmed those colours on a couple of unrestored original paint Maytags.

Now to the strange parts, the carburetor has traces of red paint under the silver (why they painted it I don't know considering it is aluminium) and the engine base has traces of black paint. I've never seen a red carb on a Maytag, but I have seen the black base. The base will be black as per the original paint (not today, I did not anticipate black - so did not buy any!).

The question is, what to do about the red carb - anyone ever seen a red one? All the engines I've seen (restored or unrestored) usually have this bare or painted silver. Some have it painted green. Seems about 50/50 on the silver or green choice.

The head with its first rough coat. I did not aim to cover absolutely everything with this coat, just to make a good start. The head and fins are an awkward shape. One thing I've learnt about painting with domestic spray cans is to go light on the coats. Lots of light coats. Give each one a day or so to try before doing the next. If you try and get too much paint on it puddles and runs - especially when you're trying to cover such a wierd shape.

These are some of the other parts with their first coat. I went just a little thicker on these parts as they are more uniform. I hang just about all parts after painting them to dry. At the time of doing this work I'm living in Berkeley California and it is early spring. Mildly warm days, followed by quite cold and very wet nights as the San Francisco fog comes rolling in. Wire hanging the parts allowed me to bring them inside and hang them in the bathroom to finish curing. The chemical process of curing paint stops when the temperature drops, and humidity (fog!) does horrible things to the finish.

A word on the paints I use... I go down to the local hardware and pick good quality automotive spray paints. Usually with some kind of rust inhibitor built in. In this case, I used Krylon automotive. You cannot always get the colours you want in automotive so you can use an automotive primer then the colour coat you need. Non automotive paints will not withstand heat or fuel too well so be careful! I don't get all carried away with two pack sprays like some people do... I stick to basic, mostly because I get enough gloss from the automotive paints and they're similar to what was used by the original manufacturer. If you want to win best-in-show then you'll need to go to more effort, but for me, I just like making them go and the paint is secondary - it serves a protective function. Look at my parts, they're more than good enough for me. The head is a little ugly, but it has been very rusty at some time in its life so is pock marked and rough everywhere.

Final cleaning and painting day

This is me (taken by my five year old Matthew) applying elbow grease to the base tank. I used wire brushes, 3M scotch pads, and common household cleaner in hot water to clean everything up.

Before painting, you must thouroughly clean and rinse all the parts to make them as close to "chemically clean" as possible to allow good paint adhesion. This is me (again, courtesy Matthew) rinsing the cleaner, dirt, and rust off using the hose. Note this is my current workshop - while Berkeley has its wierd parts, there is a lot to be said about its outdoors!

The base is now cleaned up and painted. The first coat went on today (Saturday) and I'll recoat Monday evening. I know that I'll end up burning the paint coat I put on the inside of the tank in the engine eventually, but I wanted to protect the newly cleaned surfaces until there is fuel in there.

Everything that is going to be painted now is. Most of it has its second coat, the rest will get theirs on Monday when I finish the base. I was planning on doing the final coat tomorrow, but the instructions for the paint say 48 hours and since I don't want to do this again... I'll wait! As usual I will be charging towards the last second before the engine is ready to show.

Final Assembly And The Test Run