ok its a tec 8 hp which i had running good now its hard to pull the pull start and wont start unless u take off the plug and spray some sf in it im thinking bad gas is this a possibility

yeah it could be old gas and if its an old plug that would be a contributing factor or the ignition coil is not on close enough or the flywheel and coil is dirty.

If it's hard to pull the engine over, you probably have more than just a fuel/spark related problem. You should probably make sure the valves are adjusted properly. If the valves check out ok but the engine is still hard to pull over, you probably have a broken compression release mechanism on the camshaft.

yeah it would be the compression release that is bad unless something is binding. if its still able to be turned over it might be loose or worn out. i know if its like a briggs the spring is worn out. for a quick fix take it out and stretch it out a little. or for right now leave the plug loose then start it then tighten the plug if its real bad to pull but thats just if its in a hurry. now the pull start could be too tight or rubbing real tight but to check take the front off and try to spin the flywheel by hand to see if its hard to turn

how could I tighten the plug while the engine is running? Cannot get a deep socket on the spark plug with the wire on it. I have the same problem with a B/S 15.5 28N707...thanks

Once again, if the engine has any age on it and it's hard to turn over or pull over, it probably has a valve clearance problem. You need to pull the valve cover off and check the valve clearance. If I'm not mistaken, the engine you have is a flat head engine. If this is the case, you will have to remove the valves and grind the ends or slip a flat file between the valve and push rod and grind them that way.

To adjust the valves properly, turn the engine over until it is at TDC on the compression stroke (piston at the top of it's stroke and both valves closed), and then turn it a little further until the piston drops down approximately 1/4". Check the valve clearance with a feeler gage and you should have 0.005"-0.007" on the intake side and 0.009"-0.011" on exhaust side (someone may need to check my numbers here because this is from memory). If the valves are too tight, push them back with a screw drive and slip a file between the valve and push rod and file it until you have to correct clearance. You want to do this a little at a time and check clearance often so you don't take off too much material. If you grind them too far you will have to remove the head and lap the valves or grind the valve seat.

I'm speaking from experience here because I've had several 28V707 engines that wouldn't even turn over with a brand new 300 CCA battery. In every single case, the valves were out of spec. After regrinding the valves, the engine would turn over easy.

http://www.hobbytalk.com/bbs1/showthread.php?t=111448 you can try this to get you going for right now, though i don't recommend it for long.

I'm a little lost..how do the valve stems get longer so that you have to grind them down and how does that stop the over compression problem in the cylinder? thanks

I wasn't really thinking when I made the last post...it's more for somone that has an engine with low compression.

To answer your question, the valve stems "get longer" by normal wear in the engine. The valves are basically hammered against the valve seats which causes the seat to flatten out over time. this will cause the valve to seat down further than its suppose to and will close up your valve clearance. This problem would cause a low compression condition.

Another thing that causes valve clearance problems is wear on the cam. As the cam lobes wear down, the push rods are not pushed up as far as they are suppose to go and your valve clearance will be too large. In this case you would have a high compression condition simiilar to what you have described.

Either way, you need to pull the valve cover off and take a look at your valves to determine if they are within spec. If they are, you probably have a problem the battery or starter (I'm pretty sure the 28N707 does not have a mechanical compressison release...it's all in the valve timing).

thats what i'm thinking as well, the battery more then likely, not even 150 cranking amps will turn over my murray 8's engine. and thats a 8 hp engine. the battery i have in the noma caries a 275, and when fully charged its good, halfly charged and it doesn't do nothing but lope till it starts, which i need a 300ca battery, new one, the old one needs replacing. 300ca, WHY? it has lights i use sometimes at night that runs off the battery.

how do I adjust the timing?

the engine has never been touched internally right? then it will be set correctly, just the cam may be worn as well. may be one of those plastic cams, usually steel ones never give this problem. whats your cranking amps and age of the battery your using in it?