I've owned this Troybuilt tractor with a B&S 18HP for about 8 years now and have been having problems with it now for about 4 years. What I thought was just the batteries going dead is now very questionable. Just this past summer I bought a new battery and it worked fine for about 2 months but again the engine will not crank over, I mean it will move but it comes back to the same position without revolving once. It's like there was too much compression so what I did was I loosened the oil dipstick and pulled it out about an inch and then tried starting it and it turned over and started like no tomorrow.

So my question is what would be causing this pressure build-up inside the crankcase that's so high it will not allow the engine to turn over at all even with trying to jump starting it with a car battery?

This is an Intek OHV 18HP engine with 90 hours of use, new oil this past summer.

Check your oil to see if it is over filled or has any gas mixed in with it. Back to you

Check your valve clearance

Hey topthumb,

Both the previous answers could cause the problem. And, it is probably one of them that is the issue.

1) If the carburetor is leaking gas through when the engine is shut off it can be filling a cylindeer with gas and cause it not to crank over. This can be found by checking the oil to see if there is a gas smell to it and if it is overfull. Solution: rebuild/clean the carburetor or replace it and you're done.

2) If the valves are out of adjustment it will have too much compression. When the valves are adjusted properly it releases the compression when cranking and lets it start easier. There is a video on YouTube that explans how to adjust the valves. It's pretty simple with the right tools.

Hope this help understand.

Thanks everyone, I checked the oil and it's just under the full mark and there is no 'gas' smell to it so most likely it is the valves. I'll see if I can find that uTube video and check the valves.

OK, I found that video and have a question, he says to torque the rocket set screw to 45 lbs. but in my manual it says 35 lb-in.

My question is does that mean 35 inch pounds or 35 foot pounds?

Here is the video I usually recommend:

http://www.youtube.com/user/IFIXIT4U#p/u/3/hGkn0jR9RJM

I think the problem is solved. I checked the valve clearance and they were too loose but not by much, maybe .002 or so but I guess that's enough. The engine now cranks over and even sounds a little better and smother.

Thanks for all the input guys.