tripleguy 68 Posted June 16, 2010 My 16 hp Briggs opposed twin won't start after it's hot and I leave it sit for a while. I'm wondering is the issue the carb or coil? Here's the scoop: I had to take the anti-afterfire solenoid out and clip the end off the needle. Since then, I'm wondering if while it sits, the carb might be still getting gas in the bowl? The last time it didn't re-start, I cranked with the air cleaner off and I noticed gas droplets splashing out of the top of the carb - it was getting gas. Thinking there was too much gas in there, I removed the solenoid and let the bowl gas drain and it then started. The cold starts are just fine - it fires right up. So might this be a coil issue or is it as I suspect, a carb problem? Any thoughts on fixing - I don't like not being able to shut it down to take a break and finish it up later. Thanks in advance! Share this post Link to post Share on other sites
LPH-5 0 Posted June 16, 2010 Hello Bill, See if it has spark both plugs, or very weak spark when it gets hot, that will tell you if its the carb or the coil,, Good Luck..Bill yes just put the plug with the wire attached against the head,, Share this post Link to post Share on other sites
tripleguy 68 Posted June 16, 2010 Thanks, yes, I'll need to check that. And what's a safe way to test for spark? Used to be you'd pull a plug and hold it up against the block while someone cranks the engine but that's not recommended. Is there a cheap tester or a better method? Share this post Link to post Share on other sites
BMinor8806 0 Posted June 17, 2010 Most likely the coil, same thing happened to my 818GT. Share this post Link to post Share on other sites
tripleguy 68 Posted June 17, 2010 Thanks - I'm thinking that too. New coil is probably in order and new plug wires while I'm at it. Share this post Link to post Share on other sites
JohnMBerst 36 Posted June 17, 2010 Must be in the air, as my 12.5 twin has the same problem. I did replace the coil as a few weeks past, would start, run for 10 minutes and them just quickly die. Now with new coil, starts and will run for an hour, shut it down, and 5-10 minutes latter, no go. Dealer thought it might be the newer anti-afterfire solenoid (about 10 months old) getting too warm and not opening up. Have to find some time to check it out. Compression was 80 - 95 each side. Great post, and thanks. Going out now for some seat time. Share this post Link to post Share on other sites
tripleguy 68 Posted June 17, 2010 My solenoid has the first 1/4" clipped off the needle. Seems to work just fine - make sure if you do that you idle down for at least 30 seconds or BIG bang! Share this post Link to post Share on other sites
HubbardRA 19 Posted June 17, 2010 Put a shut-off valve in the fuel line. Turn the fuel off and then let the engine run for 10 to 15 seconds before shutting down. This will prevent flooding while sitting. The manual valve will also replace the electric gas shut-off solenoid that was disabled. Share this post Link to post Share on other sites