How can I "beef Up" my Tecumseh?
- Thread starter SethC94
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Doc Sprocket
*********
While aftermarket performance goodies are hard to come by for a Tec, the usual tips and tricks apply. High flow intake and exhaust, jetting, porting, timing, etc.
r_chez_08
Should be in the shop...
Think of an engine as an air pump- the less restrictive it is, the more air it will pump.
A high flowing air filter and a diy straight pipe of between 12 and 18" long should yield an extra HP or 2.
If you really want to mod the motor, you are starting from the wrong place. Thee are limited performance accessories for the techumseh motors. However, if you are willing to spend some time, a lot can be done for little money, providing you have a few tools.
For example- with some abrasive paper of various grits, a sheet of glass or marble and some 3M adhesive spray you can shave the head and bump the compression.
With a dremel tool or even a drill with grinding drums you can port out the ports, and even bore the carb a little.
With some cheap index drills, you can drill your own jets and 'plug chop' to get the mixture right.
With a welder and drill you can create your own header and air filter adapter, and even carb adapters.
Please remember though- these are industrial motors designed to be run at 3600rpm, an have a governing system to do so. Removal of the governor and doing any other mods to increase rpm and power will most likely shorten the engine life span.
There are two major weak links when you start to increase revs over 4500rpm- the connecting rod and the flywheel. If you plan to remove the governor and use the stock connecting rod, make sure that the oil level and quality is checked regularly, and plenty of high quality correct grade oil is used, and replaced regularly.
I think arc sell a billet rod and maybe flywheel for some tec engines.
A high flowing air filter and a diy straight pipe of between 12 and 18" long should yield an extra HP or 2.
If you really want to mod the motor, you are starting from the wrong place. Thee are limited performance accessories for the techumseh motors. However, if you are willing to spend some time, a lot can be done for little money, providing you have a few tools.
For example- with some abrasive paper of various grits, a sheet of glass or marble and some 3M adhesive spray you can shave the head and bump the compression.
With a dremel tool or even a drill with grinding drums you can port out the ports, and even bore the carb a little.
With some cheap index drills, you can drill your own jets and 'plug chop' to get the mixture right.
With a welder and drill you can create your own header and air filter adapter, and even carb adapters.
Please remember though- these are industrial motors designed to be run at 3600rpm, an have a governing system to do so. Removal of the governor and doing any other mods to increase rpm and power will most likely shorten the engine life span.
There are two major weak links when you start to increase revs over 4500rpm- the connecting rod and the flywheel. If you plan to remove the governor and use the stock connecting rod, make sure that the oil level and quality is checked regularly, and plenty of high quality correct grade oil is used, and replaced regularly.
I think arc sell a billet rod and maybe flywheel for some tec engines.
klicky96
New member
Everything R-Chez said is 100% the way to go. Trust me, I ran mods on my 5.5HP Tec. a while back. I went to TSC, bought a 6" piece of muffler, cut it in 3rds, and put metal screening in between the sections to expand out the heat and reduce the flame before it empties from the exhaust. Yes, it was a little too short, but the flame did not exit the exhaust and it had a easier flow than the stock exhaust. Also, a quick clean job with a dremel on the intake, exhaust, and head made a huge difference. You don't even need to port unless you want to because when you clean it, it will make a hellluva difference. A nice carb cleaning every once in a while will keep your performance good. Also, a nice, platinum, 3-point spark plug is nice.
I got lucky with mine though. I found a honda coil that would fit mine. I guess it was a better quality coil so I put it on. Had to create a little bracket to mount it, but it did create a better spark, and well, I got it for free.
Just remember, the little things you don't even think of doing, they will give you a performance increase.
Now another thing, you can get eternal, you can buy valve springs for a honda and mount them in there, but you shouldn't. My brother tried, and his engine decide to shatter the end of the valve and put a hole in the valve cover. If you decide to try and swap out springs with other engines, it will take more than just springs. You need to upgrade to a heavy-duty valve before trying the springs.
Another thing to do is bore and sleeve the cylinder and through in a larger piston. This would require some machining, the new piston head, and maybe a con-rod. I would only do this if you really wanna have a high performance engine and you have the money.
In my opinion, I would not do anything eternal. I would keep to porting, polishing, exhaust, and a rejet. That is the much easier, much cheaper way to go, and any Do-It-Yourselfer can do it.
I got lucky with mine though. I found a honda coil that would fit mine. I guess it was a better quality coil so I put it on. Had to create a little bracket to mount it, but it did create a better spark, and well, I got it for free.
Just remember, the little things you don't even think of doing, they will give you a performance increase.
Now another thing, you can get eternal, you can buy valve springs for a honda and mount them in there, but you shouldn't. My brother tried, and his engine decide to shatter the end of the valve and put a hole in the valve cover. If you decide to try and swap out springs with other engines, it will take more than just springs. You need to upgrade to a heavy-duty valve before trying the springs.
Another thing to do is bore and sleeve the cylinder and through in a larger piston. This would require some machining, the new piston head, and maybe a con-rod. I would only do this if you really wanna have a high performance engine and you have the money.
In my opinion, I would not do anything eternal. I would keep to porting, polishing, exhaust, and a rejet. That is the much easier, much cheaper way to go, and any Do-It-Yourselfer can do it.
klicky96
New member
A straight pipe is just a straight piece of steel tubing used as an exhaust pipe.
r_chez_08
Should be in the shop...
Basically get a piece of steel plate and make up a flange, or cut the old one off your muffler. Then get some thin (ish) walled steel pipe with an I/D close to that of the port diameter. Weld the pipe to the flange so that it points away from the driver and preferably towards the ground. Multiple lengths of pipe can be welded together to step up the diameter, this is known as a stage header. You can also add curves, but be aware, too many or too tight a curve can cause restriction.
Get a Mikuni 22mm carb. There ARE Tecumseh performance parts. ARC makes a billet rod for an OHV Tec that will fit some flat heads. I have an HS50 and I am searching the deepest depths of the internet for parts. I will post them here when I find them They are out there, believe me. I know of a guy with an HS50 that has a custom grind Isky cam, beefy springs and valves (from a Honda I think), billet flywheel, billet rod, some kind of aftermarket piston, aftermarket crank, and he TIG welded a bunch of spots on the inside of the crank case to strengthen high stress areas. This is my blueprint for my engine. I just need to find out what parts from other engines fit mine.
Edit:
Found the rod that fits HS50, 5.5 and 6.0 HP OHV Tecumsehs
http://www.arcracing.com/servlet/the-274/Briggs-&-Stratton-Rod/Detail
Found custom cam grinds. Expensive but if you are serious, you are serious.
http://www.smallenginecams.com/fr_store.cfm
Edit:
Found the rod that fits HS50, 5.5 and 6.0 HP OHV Tecumsehs
http://www.arcracing.com/servlet/the-274/Briggs-&-Stratton-Rod/Detail
Found custom cam grinds. Expensive but if you are serious, you are serious.
http://www.smallenginecams.com/fr_store.cfm
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