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Right, static pressure tests (i.e., drop tests) won't work with any flange leakage. That's why I'm using a pressure regulator. I didn't expect the wood (easy to make) flanges to leak so much, but c'est la vie, as long as the regulator can keep up. I don't have equipment to supply a steady...

I only checked for crankcase leaks because it was so easy once I was hooked up anyway to check for crankshaft seal leaks. Those are crankcase leaks, too, so maybe I'm misinterpreting your question (??). I have no reason to suspect a leak, but since I am building up a mower I want to make sure...

Well, I went ahead and fabricated a crankcase leakage test rig. I set the regulator to provide about 5 psi and hooked it up to the exhaust port (the photo was taken before setting the psi). I found no leakage from either seal. My cheap-o flange made of plywood sure leaked, though. I had this...

Seals leaking under vacuum is a common cause of the engine not running well since it's only supposed to draw from the carburetor, so I'm not against that check, but I was hoping a few inches of air pressure would identify that problem. This test is simpler to see the leak by spraying soapy...

Does anyone out there have a good way of checking crankcase leakage? I've got a good F engine with 92 cold PSI, so I'd like to use it without breaking the crankcase open or replacing the seals if they're OK. I'm thinking of rigging up a flange to put on the exhaust port and putting a slight...

You have a D641 engine made in 1977 or 1978. The minimum compression ratio for this engine is 70 psi. Normal when cold is 90-105 psi; when hot it should be 80-95 psi. Since you are below the minimum and way below the expected cold range, it could still start, but I'd be surprised if it...

Awesome find. What will you use to clean up the deck? Did she set you back much?

7268's are F-engine models made from 1978 to 1982.

Thanks so much, Viper.

Where do you get your decals, Lawnz 420? I finished a complete restoration and wouldn't mind putting decals on it.

Have you got full restoration in mind?

Where are you located? I prefer F-Engine Lawn-Boys from that era. Is this an aluminum deck model? For that matter, why don't you want to fix it and keep using it? These mowers can last pretty much forever. 31 Years! You would have gone through 5 or 6 non-Lawn-Boy mowers in that time frame!

Did you just get it, or have you been using it its whole life? Pull the plug. Any fuel or fuel smell? How many hours on it?

Nice looking mowery you got there. Is it getting spark? What do you mean by "it's getting the fuel"? Are you finding fuel on the sparkplug? Does the mower seem to fire at all?

You say 30 to 45 minutes cooldown and it'll restart. Try taking action to cool the ignition module down a lot faster and see if that restores it to working. Maybe put your vacuum sweeper hose on the outlet side and get 'er temperature down inside of five minuets.

Did you try cooking it yet? For no good reason that I can think of, some of them can be returned to working order by heating them up.. You can take it out and put the module in the oven at a fairly low temp (I dunno, maybe 250?) for a while. I fixed one by simply blowing it with a heat gun...

This is a 1978 Lawn-Boy with the F200 engine. It's a plastic carburetor, right? Or is it a commercial mower?

No, Joe. I feel bad for agreeing with Bert. I'm sure there are plenty of things you know better than I. And that's what we're here for - to help each other. Don't hesitate a second to ask questions!

"I am always dissapointed with how bad the knowledge of simple electrical principles is throughout the entire population" Couldn't agree with you more.

Bert: The alternator current has to be going through a rectifier (probably full-wave) or it wouldn't charge the battery since the negative pulse would counter the positive one. John, As Bert said, due to the simplistic design (~3000 Hz pulse) it's not practical at all to measure with equipment...

The alternator on the Lawn-Boy uses the magnet in the flywheel. This means that it is generating a pulse of voltage as the magnet passes next to the alternator, and generates nothing for the rest of the revolution. Your meter, set for DC volts, is designed and calibrated to measure a...

OK, thanks. I'll try to help with the terminology. An amp-hour is, as the name implies, an ampere of current flow for an hour. This is a battery rating, since batteries are storage devices, as opposed to a generator, which produces potential power as long as it's being turned (not a storage...

Check "Ah"? Is that a typo?

A few more years? Do the basic maintenance on it and you can pass it on to your kids.

How well does this work without the bag to catch the grass? If you have the door open, doesn't it shoot the grass right at you? I parted out one of these last fall because I didn't have the bag and, without the bag, the handle is (to me anyway) embarrassing.

I'll assume you aren't a Lawn-Boy addict (like myself). These are mufflers. Lawn-Boy's are two-stroke. Their exhaust ports are on the bottom of the engine and mate up with mufflers underneath the deck. This makes them quiet. The unburnt oil in the exhaust collects in them. You need to...

Looks like new now. Good job! When I click on them I get a PhotoBucket advertisement, BTW.

Where's the flames coming out of the holes?

You should start a new thread rather than necromancing this one. : )

It did seem to me to be running very fast in your video. I use an old Craftsman tuneup meter to do my RPM checks. It works good, but it's not that easy to set up since it is supposed to be getting power from the car's battery, which the Lawn-Boy doesn't have, of course. I run it to a 12 VDC...

Was it expensive to get it done like that?

Old Lawn-Boys aren't that hard to find. I have two for sale right now and there are always some on eBay. I also see some on Craig's List every once in a while.

Man that looks nice! How did you / Where did you get powder coating done?

Our posts crossed, I intended this for M33Kent77, not you. Sorry if it came across the wrong way.

This isn't the place to teach how to use Microsoft Paint. I tried searching with this string "how to resize an image with paint" and got lots of answers.

When you say it doesn't rev up like it should, are you saying you can't make the engine speed up with the throttle control? I had an F-engine one that had this issue and it took me forever to figure out what was happening. With mine, the vane sometimes could rub on the shroud opening and stick...

Yeah, I was talking about your friends mower. Reeds can theoretically be a problem, but unless someone is messing with them (bending them, 'adjusting' them, rough-cleaning them, etc.) they are very reliable. I'm touching on the easy-to-check/easy-to-fix things first. We have guys that are...

Great spark, but are you certain that the timing is right? Is premix getting into the cylinder? Got any pictures of it?

I wouldn't be doing permanent changes just yet. Is yours also a 10323? I think the second thing to check is the primer. Try eliminating it by plugging its connection to the carburetor (I use a short piece of tube with a screw in the end). Since you can't prime it while doing this...

Easiest thing to check first is also a common cause of this: See if it still behaves this way with the gas cap removed. If the problem disappears, it is due to a clogged vent in the cap.

I think you have that wrong. The AE means electric start. There is no A separate from the E. For instance, Model 7271AE is electric start, but it is not self-propelled.

They look good to me. I'd be happy to trade for the 3-speed parts mower I have. Do you live anywhere near Toledo, OH?

You could also use a piece of wire from a wire brush.

I just checked my own stuff and I have a 3-speed Lawn-Boy parts mower which I would be happy to trade for a Walbro carburetor with the whole air cleaner still on it. Heck, I'd trade it for just a decent air filter cover from an F-engined mower/Toro 93-1231!

There's a dealer going out of business that has a new 3-speed Lawn-Boy that he took parts off of years ago. Let me know if either of you live near Toledo, OH and are interested. I could go back and take a closer look. I'm a push mower, AL deck kind of guy, so I didn't look at it very closely...

I keep the The Big Manual always available on my site. Here's a link: The Big Manual It's 639 pages, 144 MBytes, so be patient. It should have everything you ever wanted to know about your new mower, a 1987 model, BTW.

When you say you put it away with no gas, do you mean you drained the entire fuel system, and then ran the engine until there was no fuel left in the carburetor? Also, I'm a little confused by your statement "Even with the air filter removed". Did it run better with no air filter before...

Are you replacing it with the same type engine?

Can't tell whether "Put it on the list!" means you are going to go with running it out of gas after each use, at least for a while. Also, are you planning on not running it out of gas after you change the needle valves and seats?

Glad to hear it's running well. Automotive "Grabber Green" is just about the perfect match for Lawn-Boy green, if you can talk her into it. The two bolts you are missing are special shoulder/built-in washer bolts that thread into nylon square pop-in nuts. The threads are the only thing normal...