225 OMC mild backfire(exhaust)

[Mahoney]

I am getting a very quiet backfire around idle to 1500 rpm or so, no sound whatsoever from engine. The backfire is not toally constant and occures once about every second or 2(very quiet, but I can hear it) I don't recal this from running it before.<br /><br />The only thing I have done recently was to complete the charging circuit, so now volts are ~13.5-14.5 when running, compared to 11.5 or so previously. I also put a good does of seafoam in the carb , let it sit, and ran it out(on muffs).<br /><br />I am thinking it may just want to get some exercise, what do you guys think.<br /><br />I am taking it out tomorrow and want to be able to look out for anything.<br /><br />Thanks

 

[jlshields]

Re: 225 OMC mild backfire(exhaust)

Backfire thru the exhaust sounds like a sticky or burnt exhaust valve. Sticky valve could be intermittent but a burnt valve would be constant. Try some Seafoam in the crankcase for sticky, valve job for burnt.