Looking for some help to try and identify an A&M gas engine that i got in a recent transaction. The owner couldnt remember the size. It is stamped a&m and the only numbers i can find are 49zn2 and 37H8w or it could be 37HBW. There is a V1B also on the case. I need to get an ignition set up for it. I am new to gas engines so any help here would be greatly appreciated. Thanks

If you have any images that would help.

Throw a picture up for us to see

Call CH ignitions for your needs

http://www.ch-ignitions.com/ord.html

you guys are fast . I posted a few pics.

I'm not an expert but it looks 3.2 ish to me

Duane, that looks like the cylinder on my Brison 3.2 but the numbers are different. The spacing if the muffler screws is 1 3/8. The maximum dimensions of the exhaust port are 1 by 5/8. Dan.

I thought one of those numbers was the bore of the cylinder in mm?

I was comparing it with a Brison also

The 49zn2 is on the base of the jug and makes it a 3.2. You might want to check the color of the connecting rod to determine if it's a good crank or a bad one. Many of them were corrected by Gary Allison when he bought the line and started Brison.

Dammit Pat, I was never coming back to this forum...But
49ZN2 is a 4.2, 47ZN2 is a 3.7, 44 ZN is a 3.2...
The numbers are bore size in millimeters...[>:]
TKG, you were right...
To the best of my limited knowledge Gary never used copper plated Sachs rods...Gary's cranks still used/use pressed in drawn cup needle rollers. Genuine Sachs and all other real gassers use REAL caged rollers...

I measured the exhaust mounts and they are 1 1/2 " on center and a quick glance at the overall exhaust is about 2" so with that and the 49zn2 i'm going with it must be a 4.2. Now I did read something that if the crank case was milled it had something to do with ???just cant remember what? The crank case is milled. With that said do I need to open it up and check the crank as you guys mentioned? Second the engine has only had about 3/4 of a gallon of fuel ran thru it for break in according to the original owner so what is the expectant crank failure if it has the older crank? One last question is what type of ignition module should I get for it? I will call the above mentioned company this week but was looking for recomendations. Thanks sorry to be so long winded... .

When you call CH, they will ask you a couple guestions about what is on your engine and make some recommendations for your engine

They are in Wyoming so will be a hour behind you

I thought about it more last night and you're right. The 44 is the 3.2. Thanks for fixing that. I meant to correct it before retiring but you know who that goes...

It may be a 3.7 , the carb block is black and most 4.2 has a green block, that has been what I have always ran into. I had bought a a&m 4.2 but when I tore it down it was a 3.7 I had bought it cause I needed a 4.2 cylinder and the cylinder was different only by bore and the carb block other wise it lookes the same.

One other thing is if it looks like the size of a 3.2 it may be a 3.3 if the exhaust port is the same as the 4.2

The chainsaw bible says there is NO 3.3
A 49MM BORE is A 4.1 or 4.2, there are two close versions...
I guess I could scan the book

well since i am new to gas engines i guess i have to wait and see if the company that sells ignitions can tell me what it is.

It doesn't matter what size it is for a new ignition

Sachs model 122 Super, 123 Bore 47mm stroke 40mm 70cc 4.2 cu Inch
Model 117, 119, 120 Bore 47mm stroke 35mm 3.7 cu inch
Model 120 super Bore 49mm stroke 36mm 68cc 4.1 Cu inch
Model 111, 115, bore 44mm stroke 34mm 3.2 cu inch
Model 112, 113, 114 Bore 45mm stroke 32mm 3.1 cu inch
Model 116 bore 45mm stroke 35mm 3.4 cu inch
The lightest versions of all models are usually used for airplane engines...

Same ignition module for all those A&M engines. I went through 3 of the 3.2 engines in the early 90's. They all had bad cranks/bearings. They would go 8-10 hours before they went out, all while running the factory recommended oil mix. A friend had one and we put in my plane to test it. It went out in about 2 hours as I remember. I finally got A&M to trade me up to their new design 4.2 after the last blow-up. I only bench ran this engine, and got out of RC about '93 until about 2 years ago. Guess I'll put this engine in a plane one of these days.

Anyone know how this A&M 4.2 engine turned out? (This one has the crank as found in a glow engine)

Hi Antique, aren't all those cylinders made by Mahle and even the pistons? Do you have the Mahle part numbers. I'm trying to locate the Mahle part numbers for the 3.2 with the "44" molded on the cylinder. Dan.

I have been told that if you remove the carb and the connecting rod is gold colored and magnetic, it is one of the originals with the good parts. If it isn't magnetic and is white metal, it is a later model.

Sachs is now Makita, they would have the cylinder, maybe not a Mahle but will fit..and $$$...
Check with Kangke, they make the 3.2 now...

Antique, I sent you a PM. Dan.

so Sachs is the same as A&M. thanks for all the data on how to determine what size .Glad to hear it dossnt make a difference for an ignition system . So the only remaining question is how to determine if it has this bad crank or bearing isssue and what everyone did or just replaced upon failure?

Some lasted longer than others...Before Brison went away they were warranteeing the cranks for 5 years....Fly it until it gets really loose, you'll know...