"Especially seeing how sometimes a broken compression release mechanism will function then it will not, its a moving part not a cam lobe" "One that will fly out and not return until its good and ready. Hence the sometimes it spins fine and then other times it stops on the compression stroke" "after you eliminate all external probable causes then it will have to be an internal problem." First, we don't know positively that he has eliminated all external probable causes. I think, if you will check, that I told him in my first post that he may not have adjusted the valves correctly. There are other possibilities besides not following proper procedure in adjusting the valves. Also, there is nothing in any of his posts about the problem being intermittent. I sent him proper valve adjusting procedure plus compression release test to use AFTER adjusting the valves and you can also tell if it is a bad cam lobe OR the compression release mechanism its' self. Yes, a worn out cam lobe can cause much the same symptoms regardless of the presence of a mechanical compression release. I like to have some idea what I am dealing with before I just plunge in and start tearing apart. Do the cheap, easy things first. By the way, there is no "bump" in the compression release of this engine. Walt Conner

If your confident on what you have done so far, you may need to replace the camshaft. It does happen occasionally. If you take a known good battery with good jumper cables put the + lead to the starter leg and momentarily ground the other cable directly to the block or starter housing and you have the same results at least you would know something outside the engine is causing the no crank. (DO this safely as it will spark and will ignite fuel) Did the engine blow blue smoke before this? I wouldn't call it impossible for excessive carbon to build up in the head. These take out their share of headgaskets. You also weren't specific on what you installed for parts IE size of battery, new B&S starter or aftermarket?

If you want to rule out the valve issue, then just roll this tractor to where your car is. Put a set of booster cables on the car battery. Put the positive cable onto the terminal on the starter that has the heavy cable attached to it. Take the negative booster cable and press it firmly against the engine block or tractor chassis with the ignition key in the "ON" position. If the engine spins over easily and starts, remove the negative cable from the engine block or tractor frame. Try this a few times. If you get the same results, then you just proved two things. 1. The valves are likely adjusted correctly 2. Your tractor has a seperate starting solenoid somewhere. So let's pretend that the above scenario has occurred. Next step. Take the booster cable off of the starting mower. Trace the heavy wire that is on the starter motor back to the starter solenoid. Put the positive booster cable onto the OTHER big terminal on this solenoid. Clamp the negative booster cable lead to a clean spot on the engine block or the tractor frame so that it makes good electrical contact. Now try starting the tractor with the keyswitch. If the clicking noise is still there, the a new solenoid should solve the problem. The clicking sound is the solenoid pulling in. However, the round disc inside the solenoid is not making proper electrical contact and needs to be replaced.

Well you really should post the model number of the engine to insure we know what 17 hp B&S you have, there is more than one. Did you remove the spark plug to see if the engine was hydro-locked? Gas in cylinder? The solenoid valve will not prevent the carb from leaking gas into the cylinder and from there into the oil. You need to fix the carb float AND install an inline gas shutoff valve and use it when the engine is not running. I have detailed instruction on valve adjustment as well as compression release test and more IF you would like them. Address below, put in proper format and remind me along with model number. Walt Conner wconner5 at frontier dot com