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Why won't engine run?


michaeljp86's Avatar
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03-15-06, 06:46 PM   #1  
Why won't engine run?

Ok I have 3 briggs & stratton 3hp horizontal shaft engines. All 3 are very old and one was on a gocart about 5 years ago and ran great. The other 2 are from 50s or 60s. Ive been playing around with them for a while and cant get them to run. They have good spark and fuel, on 2 I took the carb off and sprayed starting fluid in it and one gave me a few puffs but wont run on fuel. Is there anything else I should check that Im missing?

 
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03-15-06, 07:00 PM   #2  
Check for compression,you may have a bad head gasket,or a stuck valve

 
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03-15-06, 07:01 PM   #3  
Have you checked the flywheel keys? I'd also check compression....

 
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03-15-06, 07:03 PM   #4  
I never took the head off to see if valves are moving, I almost did but I took the little plate off the side and could see the valve springs and the rod was moving so I think the valves would move too, or am I wrong?

 
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03-15-06, 07:04 PM   #5  
tomarrow Ill play around and see what I can find.

 
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03-15-06, 07:06 PM   #6  
Ok, when rotating the crank, the piston is moving, and both valve springs get compressed? Then yes, they work, but that doesn't rule out bad sealing valves, or a blown head gasket, or rings. (that side plate is the breather also)

 
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03-15-06, 07:09 PM   #7  
Posted By: v8driver Ok, when rotating the crank, the piston is moving, and both valve springs get compressed? Then yes, they work, but that doesn't rule out bad sealing valves, or a blown head gasket, or rings. (that side plate is the breather also)
These engines just have a tube from this plate, it doesnt go into the intake like new engines.

 
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03-15-06, 11:19 PM   #8  
I think I'd start with checking the compression, if you've verified they have good spark. For some reason, these engines seem to be a tad prone to valve seating problems. Although they move up and down, they may not be sealing against the seats.


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03-17-06, 08:37 AM   #9  
You say they have spark and fuel?? Did you mean fresh fuel in the tank or does your spark plug look wet with fuel when you pull the plug after trying to start it? If you spray staring fluid in the top of the carb where the air filter goes and it fires it sound to me that you aren't getting fuel? I'm not a pro small engine guy but this is what I would try....pull the carb off, on the bottom of the bowl there should be a hex head bolt. Remove that and you will see a float for your fuel bowl. Remove the pin for that and there will be a square needle valve. Take it all apart and clean it good. Where the needle valve seats in the carb there is a tube, I think it's call a metering tube. You can remove it with a screwdriver, it will have a slot. The tube will be a inch or so long. One the side of the tube is a small hole. That could be plugged up causing fuel starvation. Take a small piece of wire and clean that tube and hole good. I'v had success doing that. Good Luck

 
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03-17-06, 09:59 AM   #10  
I will give that a try, but only one engine would fire every once in a while with starting fluid and thats with no carb at all. When I sprayed it in with carb on I got nothing. I will try the cleaning the carb thing hopefuly today. Thanks for helping and wish me luck.

 
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03-17-06, 12:39 PM   #11  
How do I take the valves out???????

Ok I took carb all apart and have it soaking in detergent and have it cleaned up real nice. I also took the cylinder head off and would like to claen the carbon out from around the valves. I never did this before so how do I take the valves out?

 
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03-18-06, 11:32 AM   #12  
Theres little spring keepers at the end, I've gotten them out with a flat head a few times. Compress the spring while you pull em out.

 
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03-18-06, 04:16 PM   #13  
Ive done cars before but its so tight in there I couldnt see them. Ill give it a try tomarrow.

 
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