# tecumseh 5hp loses power



## river (Nov 23, 2008)

Hi there, I am new to this site and exited to see the amount of information in here. I always love forums.
My problem is whit my antique snowblower. It's an Eaton Viking with a hs50-67075 tecumseh motor(5hp). It's got points and a condensor that were changed 2 years ago. The model of the snowblower is 324-450.
The problem is that after about 30 or 40 minutes of use, it loses power. The engine seems almost as if it's running on idle, even with full throttle. At first, when it's cold, it's got lots of power considering the size of motor. It starts easily, a couple of manual cranks with choke. Whitin a second, I can completely shut off the choke and it runs good. It's got no primer bulb.
I've also seen it stall, tried replacing the spark plug and didn't do any good. If I let it stand for a while (1 hour or so), it's good to go. The spark plug is a bit black but doesn't seem that bad.
Any ideas where I should start. I've been suggested to replace the coil but they are about 50$ but I havent had the one that's on there tested yet. I wanted to wait to see if something else would help before putting that much money in something 35 years old.

Thanks for any suggestions.


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## 30yearTech (Sep 14, 2006)

Test for spark when it stalls, this will pretty much tell you if the coil is failing when it gets hot. Also check the fuel cap for proper venting of the tank. 

It sounds like you may have a valve problem, so checking the valve lash is also something to consider.

Best of Luck:thumbsup:


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## river (Nov 23, 2008)

Thanks for the reply.
Could you explain what you mean by checking the valve lash.
I dont know a whole lot about mecanics but am just starting to learn.
Thanks again.


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## 30yearTech (Sep 14, 2006)

Valve lash refers to the clearance between the lifter and the valve stem for the intake and exhaust valves on your engine. 

You can download a service manual that should cover your engine. The link can be found in the sticky post thread in the 4-cycle section on this site.


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## river (Nov 23, 2008)

Hi there,
Thanks for all your help. I think I have found the problem, it seems to be running alot better now. I used it on the last snow storm and it worked really well.
What I did was drill a small hole in the gas cap to make sure the tank wasn't creating a vaccum and then I reset the carburator valves. Didn't even need to clean it. Hope it keeps on going like this for a while.
Thanks again.


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## paulr44 (Oct 14, 2008)

FYI I've seen a number of newer Tecumseh gas caps not venting correctly. Just hope the hole you drilled isn't big enough to let snow (water) into the tank!
Paul


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