Cast Iron Engine?
#1
Cast iron Tecumseh?
Hello, my first post here. I did some trading and ended up with an electric start Miller 180E Welder/Generator. The engine is a Tecumseh OHM 120. Serial no. - KB031531. I think the model number is 220003 SER 1037D. The block is heavy cast iron. The rig weighs about 400 pounds, it appears to be very heavy duty. Low hours but has set up a while. Are these cast iron engines very common, i have never seen one before? Didn't idle good when i got it and discovered it was running way too lean. Does anyone know the proper carb adjustment or do you just go by the sound? Even though it is cast iron is it still sleeved? Engine is in excellent shape and now runs pretty good. I would like to get a carb rebuild kit just in case. Any place online to be sure you are getting the correct parts. I live in a rural area and just like to order what i need. Lot's of questions, but i would appreciate any information on this older but very dependable rig. Thanks.
#2
Hello Tex 40, and WELCOME to doityourself!
The engine you have is not very common, but it is actually a decent engine. By the numbers you gave, it is a 12 horsepower horizontal engine made on the 37th day of a year ending in 1 (such as 1971, 1981, 1991, etc...).
To adjust the air/fuel mixture screw: For a walbro carb, the idle speed mixture screw is above the bowl on the side of the carb. Screw the screw in all the way until it lightly bottoms out, then back it out 1 1/2 to 2 turns. The high speed screw is on the bottom of the carb under the bowl. Run the engine at top rpm and screw this screw in until the engine begins to lose speed. Then back it out about 1/4 turn. This should set it close to the optimum setting, you can fine tune from there if needed.
If the engine has a tillotson carb, the main mixture adjustment screw is near the bottom of the bowl, coming out the side, not underneath. To adjust this, run the engine and turn this screw in until the engine begins to slow down. Then back the screw back out about 1/4 turn. The idle screw is next to the throttle shaft lever on the side of the carb. Back it out 1 1/2 to 2 turns from closed.
As far as getting parts online...I don't do it, so I don't know who is a good company to deal with. Someone else may be able to post the address of a reputable company for you.
I hope this helps, and let us know if we can help again!
The engine you have is not very common, but it is actually a decent engine. By the numbers you gave, it is a 12 horsepower horizontal engine made on the 37th day of a year ending in 1 (such as 1971, 1981, 1991, etc...).
To adjust the air/fuel mixture screw: For a walbro carb, the idle speed mixture screw is above the bowl on the side of the carb. Screw the screw in all the way until it lightly bottoms out, then back it out 1 1/2 to 2 turns. The high speed screw is on the bottom of the carb under the bowl. Run the engine at top rpm and screw this screw in until the engine begins to lose speed. Then back it out about 1/4 turn. This should set it close to the optimum setting, you can fine tune from there if needed.
If the engine has a tillotson carb, the main mixture adjustment screw is near the bottom of the bowl, coming out the side, not underneath. To adjust this, run the engine and turn this screw in until the engine begins to slow down. Then back the screw back out about 1/4 turn. The idle screw is next to the throttle shaft lever on the side of the carb. Back it out 1 1/2 to 2 turns from closed.
As far as getting parts online...I don't do it, so I don't know who is a good company to deal with. Someone else may be able to post the address of a reputable company for you.
I hope this helps, and let us know if we can help again!
#3
OHM120
The OHM120 model is NOT CAST IRON. Miller was one of a very
few OEM's that used this model number of engine. The OHM is,
basically, a horizontal shaft version of the OVM120 or OVXL120
vertical shaft models used in many lawn tractor applications
beginning in the mid-80's. With its push rod tubes, it resembles
the larger OHH cast iron engines seen on some Miller welders,
also, but....is not the same.
Tcumcman
few OEM's that used this model number of engine. The OHM is,
basically, a horizontal shaft version of the OVM120 or OVXL120
vertical shaft models used in many lawn tractor applications
beginning in the mid-80's. With its push rod tubes, it resembles
the larger OHH cast iron engines seen on some Miller welders,
also, but....is not the same.
Tcumcman
#4
Hey guys thanks for your information. I wasn't real sure about the block just really listening to a friend who has a Miller welder that he said was cast iron and they sure do look similar. It seems to be really heavy to try to lift. Are there any problems with this particular engine? I can't seem to find much information on it so apparently it was not that popular. Very dependable so far. If i ever need to replace it what would be the best replacement engine for this type of application? Do they still make cast iron engines? Thanks.
#5
Miller Welders
Tex40,
Your friend probably has a Miller welder with an OH160 (16HP
cast-iron OHV engine) on it. They look similar, but are quite a
bit different, too. Tecumseh has CEASED MAKING ALL CAST
IRONS as of the mid-90's or thereabouts. The added expense
of these has NO DEMAND, and the assembly-line tooling to
make them is EXTREMELY EXPENSIVE to re-tool the assembly
line. Emissions requirements are also a factor now, but with ALL
OF THE ABOVE....there was just no reason to continue with
making them.
Tcumcman
Your friend probably has a Miller welder with an OH160 (16HP
cast-iron OHV engine) on it. They look similar, but are quite a
bit different, too. Tecumseh has CEASED MAKING ALL CAST
IRONS as of the mid-90's or thereabouts. The added expense
of these has NO DEMAND, and the assembly-line tooling to
make them is EXTREMELY EXPENSIVE to re-tool the assembly
line. Emissions requirements are also a factor now, but with ALL
OF THE ABOVE....there was just no reason to continue with
making them.
Tcumcman
#6
Hmmm...ok, not cast iron then. Not the engine I was thinking of. It should have a cast iron sleeve though, but it would be nice if it was all cast, huh? Even at that, I don't think there are any real problem areas with this particular engine, if it is basically the same as the OVM120. The main pain with it is if you ever have to get the head on and off. It's not that bad, but they didn't make it very simple. The valves may need adjusting from time to time. The starter bendix may also give some trouble soon, as it it several years old. No real big deal though. You might keep an eye on the pushrod tubes to check for oil leakage around them, but they usually don't pour, just seep a little. Probably even less on a horizontal engine.