Short history lesson:
Lawnboy used to part of a company called OMC, they made johns evinrude ( a lot of contract engines too like the viking for eatons ) Pioneer and others ( iron horse was a utility engine they made kind of like a matag only it was a really good engine ).
OMC got into trouble.
They went bust and the assets were sold off and broken up.
The real deal with lawnboy was they made their own engines ( rare in the lawn mower business ).
In general OMC engines are great for mowers, but no hell of other aplications.
They simply were never designed to do anything but spin a blade and cut grass ( one C-18 series blew a little snow but it wasn't very good at it ).
What you have here is a mystery to me.
I do not recognize the type ( but I kind of lost interest in 1979 when the d series ended and I decided the new F series engine was not as well made ).
The engine is probably a contract engine but I can not tell you who made it and you shoudl be wary that engines like this are hard to mount, have strange shafts that clutches will not fit and most important have flywheels so light they will not run with the extra mass of a blade to help them along.
So there you have it a post that offers you very little info and a snap shot of some history
Lawnboy used to part of a company called OMC, they made johns evinrude ( a lot of contract engines too like the viking for eatons ) Pioneer and others ( iron horse was a utility engine they made kind of like a matag only it was a really good engine ).
OMC got into trouble.
They went bust and the assets were sold off and broken up.
The real deal with lawnboy was they made their own engines ( rare in the lawn mower business ).
In general OMC engines are great for mowers, but no hell of other aplications.
They simply were never designed to do anything but spin a blade and cut grass ( one C-18 series blew a little snow but it wasn't very good at it ).
What you have here is a mystery to me.
I do not recognize the type ( but I kind of lost interest in 1979 when the d series ended and I decided the new F series engine was not as well made ).
The engine is probably a contract engine but I can not tell you who made it and you shoudl be wary that engines like this are hard to mount, have strange shafts that clutches will not fit and most important have flywheels so light they will not run with the extra mass of a blade to help them along.
So there you have it a post that offers you very little info and a snap shot of some history
Thanks for the history.
It is a M series engine, ENGINE GROUP MODELS: C21ZMRA & B Lawn Boy C21ZMRB, Lawnmower, 1991 (SN K00000001-K99999999). Still no luck on manufacturer, it has a Mikuni carb on it. The crank is pressed together and Elec. start flywheel. From what I gather this is a hard to find engine and Lawn-boy collectors want it.
The flywheel looks like it has some wait to it. If I can get the pulley off I may be able to find a small sprocket for it. :shrug:
It is a M series engine, ENGINE GROUP MODELS: C21ZMRA & B Lawn Boy C21ZMRB, Lawnmower, 1991 (SN K00000001-K99999999). Still no luck on manufacturer, it has a Mikuni carb on it. The crank is pressed together and Elec. start flywheel. From what I gather this is a hard to find engine and Lawn-boy collectors want it.
The flywheel looks like it has some wait to it. If I can get the pulley off I may be able to find a small sprocket for it. :shrug:
Simple test.
Can you pull start the engine and get it to idle without the blade?
If not your going to have a lot of trouble.
If it has a Jap carb its probably a Jap engine, that would seem to fit with the pressed together crank.
I'm not a big fan of the pressed crank for this type of engine.
Anything pressed together gest wacked out of alignment with the first stump encountered.
Can you pull start the engine and get it to idle without the blade?
If not your going to have a lot of trouble.
If it has a Jap carb its probably a Jap engine, that would seem to fit with the pressed together crank.
I'm not a big fan of the pressed crank for this type of engine.
Anything pressed together gest wacked out of alignment with the first stump encountered.
mota turn wrong way! put back in lawn mower and cut graass! lol
my old neighbor told me about putting a lawnmower engine in a bicycle at a 45, so the belt was doing another 45 degree twist to the back pulley. (since belts can twist) said it was the best bicycle engine he ever had. maybe you could do that on a minibike to a jackshaft with a standard chain clutch on it? just a thought....
my old neighbor told me about putting a lawnmower engine in a bicycle at a 45, so the belt was doing another 45 degree twist to the back pulley. (since belts can twist) said it was the best bicycle engine he ever had. maybe you could do that on a minibike to a jackshaft with a standard chain clutch on it? just a thought....
NOS, I'm beginning to think it's a Suzuki engine, Toro and Suzuki were in bed around that time. When I get time I will see if it will run without the blade.
JK, It's a 2 stroke, It will run upside down. I like where your going with that. If I can get the pulley off I can put a sprocket on it. jackshaft clutch :thumbsup: But first I will try what NOS suggested, before I get to invested in it.
JK, It's a 2 stroke, It will run upside down. I like where your going with that. If I can get the pulley off I can put a sprocket on it. jackshaft clutch :thumbsup: But first I will try what NOS suggested, before I get to invested in it.
Long ago, 4yrs maybe here a member had two lawnboy engines with shafts cut to 3/4" and powering a go-kart that was said to be stupid fast. So it's been done. I have access to a box of lawnboy engines and a couple of old mowers that supposedly run but I'm passing because I remember the member saying the machining was high as were the other mods. Someone more ambitious than me can search for the thread.:shrug:
Correction: Twas on D.I.Y. karts but was posted as a link here, I'm too groggy on my eve meds to continue researching but it's out there somewhere...............................................
Correction: Twas on D.I.Y. karts but was posted as a link here, I'm too groggy on my eve meds to continue researching but it's out there somewhere...............................................
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i just realized its a 2 stroke.... wow i cant say ive seen a 2 stroke push mower. weird. anyway in that case the only thing keeping you from running it horizontal is the carb bowl then. use the pulley thats on it to another pulley on a jackshaft with a clutch and you wont have to mess with anything else.
I have never actualy bought a lawn mower.
I have been cutting grass with remnants of mowers dating back to a 1962 purchase of an Eatens viking powered by a c series engine made in Peterborough my Grandfather bought.
And every few years since I pick up som parts here or there and make another mower to get me by.
This Usualy cost on the order of 10 dollars worth of parts.
I think the D400 is the finest Engine ever to cut grass and there are few things if any I would change on them ( maybe a better carb and CDI ignition but that is about it ).
I have a long histoory with OMC products and it actualy broke my heart to see how the arogance and stupidity of the managers destroyed it.
I would have built race engines out of them long ago if they had any chance of being good at it, but the best I can do is make them cut grass for decades.
But nothing made after 1979 was an improvement to me.
You can hitch an Oxen to a Sulky.
And it will get you down the track.
But an ox pulls a plow and a horse pulls a sulky.
Lawn mowers cut grass.
Extrapolate.....
I have been cutting grass with remnants of mowers dating back to a 1962 purchase of an Eatens viking powered by a c series engine made in Peterborough my Grandfather bought.
And every few years since I pick up som parts here or there and make another mower to get me by.
This Usualy cost on the order of 10 dollars worth of parts.
I think the D400 is the finest Engine ever to cut grass and there are few things if any I would change on them ( maybe a better carb and CDI ignition but that is about it ).
I have a long histoory with OMC products and it actualy broke my heart to see how the arogance and stupidity of the managers destroyed it.
I would have built race engines out of them long ago if they had any chance of being good at it, but the best I can do is make them cut grass for decades.
But nothing made after 1979 was an improvement to me.
You can hitch an Oxen to a Sulky.
And it will get you down the track.
But an ox pulls a plow and a horse pulls a sulky.
Lawn mowers cut grass.
Extrapolate.....
How can I make it easier to understand?
The basic engine design does not adapt itself well.
Costs involved in machining and making parts exceeds the value of the engine as compared to buyin gor building a proper horizantal shaft engine.
I am going to date myself now.
But this is a great miibike engine.
Pou
Its design easily adapts to minibikes or karts its very small and light.
It can spun to high RPM without fear of exploding.
It makes good low end torque for is size.
Pound for pound and dollar wise ( if you got each for free ) the D44 makes a simpler, cheaper and easy to build engine.
But its just one example.
Just about any horizontal 4 stroke is better than a any mower engine and the first reason is they bolt in place.
Here is another good one the Chrysler 580 power Bee
It was so much better it could be adapted to cut grass, pump water or even run a trolling motor.
And the reason is it weas a well thought out in advance general purpose engine.
It was not designed to be a lawnmower first and only.
Here's a snowboy engine based on what I suspect is a c-17a.
Great lawnmower, shitty snow thrower, but at least OMC had thegood sence not to screw everything up by trying to tip it on its side ( they knew at that much would not work )
Here's a decent little Clinton you see on a mini every now and then.
Sometimes you found them on a mower.
But there was a good reason this ( and the techumseh uniblock and AH engines too ).
Because the design was ver strong and general purpose, strong enough in the case of the little Clinton to make a decent saw motor.
I am telling you this from experience.
Listen or learn the hard way.
The basic engine design does not adapt itself well.
Costs involved in machining and making parts exceeds the value of the engine as compared to buyin gor building a proper horizantal shaft engine.
I am going to date myself now.
But this is a great miibike engine.
Its design easily adapts to minibikes or karts its very small and light.
It can spun to high RPM without fear of exploding.
It makes good low end torque for is size.
Pound for pound and dollar wise ( if you got each for free ) the D44 makes a simpler, cheaper and easy to build engine.
But its just one example.
Just about any horizontal 4 stroke is better than a any mower engine and the first reason is they bolt in place.
Here is another good one the Chrysler 580 power Bee
It was so much better it could be adapted to cut grass, pump water or even run a trolling motor.
And the reason is it weas a well thought out in advance general purpose engine.
It was not designed to be a lawnmower first and only.
Here's a snowboy engine based on what I suspect is a c-17a.
Great lawnmower, shitty snow thrower, but at least OMC had thegood sence not to screw everything up by trying to tip it on its side ( they knew at that much would not work )
Here's a decent little Clinton you see on a mini every now and then.
Sometimes you found them on a mower.
But there was a good reason this ( and the techumseh uniblock and AH engines too ).
Because the design was ver strong and general purpose, strong enough in the case of the little Clinton to make a decent saw motor.
I am telling you this from experience.
Listen or learn the hard way.
NOS,
I get your point. I appreciate your honesty and concern. And your knowledge of small 2 strokes is awesome. Honestly this engine is not a priority and I don't even know if it will run without a blade on it yet and I have two projects in front of it. The fab work I can do and the only expense I can see would be a carb if the one on it will no let the engine rev past governor speed, I can make a manifold for it. But for now it is just a toy to play with in between projects. it is a good, strong running engine that was free and as long as it does not get in to my pocket I will keep playing with it. I will not be heartbroken if it goes in the trash either.
JK,
I like your enthusiasm. But NOS is making a good point, this is not something to waste a lot of money on and it might not even work. baby steps my friend. :smile:
I get your point. I appreciate your honesty and concern. And your knowledge of small 2 strokes is awesome. Honestly this engine is not a priority and I don't even know if it will run without a blade on it yet and I have two projects in front of it. The fab work I can do and the only expense I can see would be a carb if the one on it will no let the engine rev past governor speed, I can make a manifold for it. But for now it is just a toy to play with in between projects. it is a good, strong running engine that was free and as long as it does not get in to my pocket I will keep playing with it. I will not be heartbroken if it goes in the trash either.
JK,
I like your enthusiasm. But NOS is making a good point, this is not something to waste a lot of money on and it might not even work. baby steps my friend. :smile:
NOS has some good thoughts and reasoning.
Sometimes I guess it's not always about the smartest thing to do. It's fun to experiment and be different. I'll do my lawn boy powered go kart at some point. I have the engines. I have friends who can machine parts for me. I have a welder and steel to make mounts. It's all for fun.
I'll have less money in building the engines than the price of 2 clones. Clutches might be pricey though.
I agree with you on that being one of the finest lawn boy engines ever produced....starts easy. Needs little maintenance and for its size chews up grass.
Sometimes I guess it's not always about the smartest thing to do. It's fun to experiment and be different. I'll do my lawn boy powered go kart at some point. I have the engines. I have friends who can machine parts for me. I have a welder and steel to make mounts. It's all for fun.
I'll have less money in building the engines than the price of 2 clones. Clutches might be pricey though.
I agree with you on that being one of the finest lawn boy engines ever produced....starts easy. Needs little maintenance and for its size chews up grass.