acfarmer Posted August 2, 2008 Posted August 2, 2008 Have an 18HP overhead single cylinder Kohler that cranks,has fire and compression but spits back out the carb won't start.The valves look like they are working OK.Fellow told me it is out of time.Does that seem like the problem to you fellows? If so How do I fix it? thanks
Roy Posted August 2, 2008 Posted August 2, 2008 Have no experience with them but have read that the 18 hp OHV Kohlers are fond of dropping a valve seat if overheated. Suggest you may want to pull the head and take a look.
andrewk Posted August 3, 2008 Posted August 3, 2008 A dropped valve seat would cause a low/no compression condition. First thing to do is check the flywheel key, as that controls ignition timing. If you find that the key is good, you are going to have to check cam timing. How to fix it depends on what you find. Remember, start simple. Andy
xenon172 Posted August 3, 2008 Posted August 3, 2008 Check the points and make sure they are properly set and in good condition. If they are pitted or corroded replace them as well as the condenser and make sure the points plunger pin is steel and not aluminum. This is a little easier than checking for a worn flywheel key which as stated above can also cause problems. The initial gap for the points should be .020". Once the engine is running use a timing light for final adjustments. There are several other things that can cause the symptoms you describe but this is probably the easiest place to start.
D-17_Dave Posted August 3, 2008 Posted August 3, 2008 I'm not as familiar with the 18 OHV Kohlers but the rest of the Kohlers have auto type ign. coils and the points work off the cam so the flywheel key wouldn't make a difference. Unless this engine has a magneto. How much compression does this engine have? The cam operated decompression release may be hanging or out of adjustment holding the intake valve open to much or too long. Or the valve may be working but out of adjustment. Make sure the tappet clearance is OK. Was the engine running before? If so then you can most likely rule out any internal timing issue. If you have never seen it run then take nothing for granted. Check everything.
Marine_81 Posted August 3, 2008 Posted August 3, 2008 Sounds like the timing is severely retarded. Check it, and you'll probably end up advancing it.
KSever Posted August 3, 2008 Posted August 3, 2008 Was having the some of the same symptoms with my Briggs 14P single cylinder OHV engine yesterday. It was blowing gas back out the carb, hard to crank and would not start. I was told the valves were out of adjustment, took me about 10 minutes to check the valve clearence and readjust. It started right up after that. Here's a link to my original post with my symptoms and answered by another member. In case your interested [url]http://www.simpletractors.com/club2/topic.asp?TOPIC_ID=97613[/url]
acfarmer Posted August 3, 2008 Author Posted August 3, 2008 Valve clearance seems to be fine.How does adjusting the timing work? thanks for the replies
MikeES Posted August 4, 2008 Posted August 4, 2008 The ACR (Automatic Compression Release) works on the exhaust valve so you would not get "spit back" through the carb. If you have removed the rocker arm cover and adjusted the valve clearance to .005" cold on both valves. You have adjusted points to .020" (I have mine at .018") and have a good spark, and it still spits back. Then first I would remove the head to make sure the intake valve is seating properly, and if so then it could be the cam is out of time. This can only happen with improper engine assembly. You will need to tear the engine down. Was this engine apart just before you acquired it? BTW the K361 is a hard starter. They require lots of choke and NO more than 1/4 throttle. They start the best with throttle plate in idle position.
acfarmer Posted August 4, 2008 Author Posted August 4, 2008 Thanks for the tips.I don't know anything about the history of the engine as I bought it from a guy that bought it....etc.Doesn't look like its been apart so I'll put a new set of points and condenser on it.
Marine_81 Posted August 6, 2008 Posted August 6, 2008 Try to get your hands on a repair manual of sorts; start with the Internet (that way it may be free). I'm not familiar with that particular engine, so I can't give you concise tips on timing adjustment. Most small engines are set by bringing the piston to x degrees before top dead center, then adjusting the ignition housing using a continuity tester.
andrewk Posted August 6, 2008 Posted August 6, 2008 Do we know that he's got a K361? Knowing what series the engine is will narrow down things greatly.
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