Johnson '89 48 spl, occasional miss / backfire?

Hi to all,<br /><br />My 48 has been running great since I replaced the PowerPack, but when idling very slowly or when I first start and idling in N it will idle ok but every 10 seconds or so it will kinda pop and almost die. If I then raise the trottle it runs fine again. It usually happens when I first start up after stopping and fishing etc. but it will do it all day long. I have to kinda put it in gear quickly and take off. The pop kinda sounds like a back fire, not really sure, never had the cover off to check. <br /><br />The motor runs great wot and at slower speeds, its just very slow idle??<br /><br />Any help will be appreciated.<br /><br />Sincerly,<br />Beck

Re: Johnson '89 48 spl, occasional miss / backfire?

It's possible that your idle is set too low. What are your RPM's in gear, on the water, at idle? It's also possible that you are running lean at idle, causing a sneezing symptom. Adjust your low speed needles to 2 1/2 turns out from a lightly seated position and see if this helps.

Re: Johnson '89 48 spl, occasional miss / backfire?

Rickdb1boat,<br /><br />Thanks for the reply, and that is a good way to describe what its doing "sneezing". I'm not sure of the exact rpm's, I will check tommorrow, I hope to go fishing. And I will check the low speed jets also.<br /><br />I run about 5400 rpm wide open and runs about 34 mph, but I'm not sure of the accuracy of that number as when I first installed the tack it was on 6 or 8 hundred rpm's and I zerowed it. I later read that it will reset to zero when power is applied. <br /><br />In an attempt to recalibrate it I had it idling at a friends house and used his tack to get a reading and then set mine to that reading. I figure I'm in the ballpark.<br /><br />Thanks again, <br />Beck<br /><br />I will try your recommendations and get back.