Sputters and Coughs a bit

Hi all, 1983 200 hp Johnson. When cold, idles perfect. After running for a while, it kind of hiccups every 5 seconds or so. Sounds like it might stall but doesnt. Kind of a sneezing sound. Hopefully you all know what I mean by that.<br /><br />Any ideas as to why? <br /><br />thanks,<br />Scott

Re: Sputters and Coughs a bit

For what it's worth, just one comparison: My 175 of the same era had a horrible sneezing problem at idle, often almost quitting, occasionally actually quitting. But really started and ran pretty good other than that. All the advice I got was that it was caused by a lean condition for whatever reason - often dirty carb jets, but could be anything. I was also advised that "perfect" idling is often not possible with large carbeurated 2 strokes, it's just the nature of the beast.<br /><br />Given that, I convinced my (good) mechanic that the sneezing I had was not within the realm of imperfect two stroke idling, so he agreed to spend some time (he doesn't like to waste his time and my money - I like that) troubleshooting it and would clean the carbs if need be. He found some sort of missing or damaged plug thing in the VRO/fuel pump. My VRO is disconnected and I premix. Evidently this is one of the parts that is plugged off when it's disconnected. So it was evidently causing a significant air leak, lean mixture at idle, and therefore the bad sneezing condition.<br /><br />That definitely solved the sneezing problem. It really idles very, very nicely now. I'm very happy with the result. I also noticed there's significantly less black oily exhaust residue messing up the leg.<br /><br />For what it's worth, of course. Good luck.

Re: Sputters and Coughs a bit

i had similar probs with my 1976 merc 115hp 6 cylinder...would idle bad, sneeze, backfire, whatever yo call it and sputter. i decarbed mine(through the gas, mixed with the fuel) and reset my idle mixture screws. and now it runs impecable. thought id share my 2 cents

Re: Sputters and Coughs a bit

Thanks guys. And D, I premix too, no VRO. Are you saying it was something that was not disconnected when your boat was switched to premixing?<br /><br />Mike, I just decarbed, but I used the Spray method. I have heard the other is better, I might do that after my next tank.<br /><br />Thanks again.

Re: Sputters and Coughs a bit

Originally posted by I'm_a_learning:<br /> Thanks guys. And D, I premix too, no VRO. Are you saying it was something that was not disconnected when your boat was switched to premixing?

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No, I believe (based on what he pointed out to me) that something had been disconnected, and the point at which that something went into the fuel pump/VRO unit, there was supposed to be a plug put in its place. The plug had either deteriorated or worked loose, I don't know which. Either way, as I understand it, was that there was air leaking into the fuel system at that point causing the lean-ness. At the time, he wasn't sure that this was the cause, but he thought it COULD be and knew it had to be corrected anyway. My understanding is that the fix was as easy as replacing the plug properly. It was clear as soon as he started it up, that it sounded good on idle. He gave it to me and told me to let him know if it didn't solve the problem. It did solve the problem and I assume the bad plug was the cause. I was just happy it didn't come to cleaning or rebuilding the carbs because that's beyond my repetior at this point and would have been $$ to have the pro do it.<br /><br />Obviously, I'm not a mechanic, but probably could have recognized this as not being right if I'd scrutinized the fuel pump area. It just might be something for you to check.<br /><br />On the other hand, try a search on this board as well as rec.boats on groups.google.com for the word "sneeze" and I think you'll find some other possible causes and cures. To my recollection, it often comes down to needing carb cleaning.<br /><br />

Mike, I just decarbed, but I used the Spray method. I have heard the other is better, I might do that after my next tank.[/QB]

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Since I'm a fan of the other method, I'll just chime in to say that I don't think it's better, only easier for "me" to do a good job because I don't have to sit next to the smoky motor while spraying. the one time I tried the spray method, I think I did a half a$$ed job because I was impatient.