Hello, welcome to Just Answers. My name is XXXXX XXXXX X would like to help you with your question
when you say slowly, is it consistantly slow, or faster and then slow down when it gets to compression?
Glad to meet you I'm Hal
When the starter attempts to crank the engine it will turn the crank about 1/2 turn and stop....sometimesw it backfires
The engine acts as though the exhaust valve is stuck and won't release the cylinder presure on the exhaust stroke.
ok, you may just need to adjust the valves on your engine. its pretty easy to do.
I would do a couple of quick checks first to make sure we are on the right track, but the valves are a pretty common thing to have to adjuste.
first try this. when the engine gets to the stopping point, try turning it by hand with the grass screen to just past the compression. then try starting it. if this lets it try to start then the next step is adjusting the valves. you can also try taking the plug out, grounding the plug wire, and making sure the engine will spin over nice and fast with the plug out.
When I turn it with the screen it cycles to the next compression stroke and stops again.
ok no problem. it may just be too far out. I would pull the plug and make sure it will spin fast a freely, and from there pull the valve cover off and have a look at the valves. if they are pretty far out of adjustment it will build up too much pressure in the cylinder.
Ok how are the valves adjusted?
I am going to send you a link for a video. the guy does a very good job at expaining how its done. at the start of the video the valve cover is already off. and the engine is set at 1/4 turn past top dead center on compression stroke.
you will need a feeler gauge to do it accurately. I normally set the intake at 4 thousands, and the exhaust at 5 thousands.
**if you pull the cover off, and one of the rocker arms is extremely loose, push rod bent etc.. then you may have a more severe problem. but the valve adjustment is usually all it is
Great...I'll check out the video and then the mower ...great help thanks
you are very welcome. let me know if there is anything else i can help you with, or if you run into any snags
I think that'll take care of the problem Tim.. Thanks!