Smokey Exhaust (Evinrude 30hp)

[zdmaster2k]

Another problem for you to ponder...!The 'rude 30 (which, despite all its problems cold starts surprisingly well)produces a very smokey exhaust at the start of a day of operating, it may not have been used for up to a week. The smokey exhaust stops however after a few hours of running. I'm sure it's not the fuel mix, I ensure that's the recommended 1:100 and always shake the tank before use.

 

[G DANE]

Re: Smokey Exhaust (Evinrude 30hp)

Mine always did this when is was cold weather, its just from the cooling water being mixed with the hot exhaust gasses. If it starts doing so in warmer weather its time for an impeller/water pump repalcement, the amount of pumped water falls with pump age, and temperature will rise. I cold weater they all do so.<br /><br />Put your hand at the iddle exhaust relief holes and you will notice its warm.

 

[JB]

Re: Smokey Exhaust (Evinrude 30hp)

Assuming that your engine is an 80s model (You always need to tell us that) you should go to the now recommended 50:1 mix, Bosun.<br /><br />After many failed engines due to inadequate oil coating in the crankcase on those 80s engines OMC changed their recommendation on all engines previously run at 100:1 to use a 50:1 mix.<br /><br />I agree with G Dane. I think what you are seeing is largely steam until the engine is warmed up and the exhaust path is fully heated.

 

[umblecumbuz]

Re: Smokey Exhaust (Evinrude 30hp)

Quote from Bosun: 'The smokey exhaust stops after a FEW HOURS of running..'<br /><br />A few hours? Are we talking smoke here - or condensing of the combustion products? Would it take that long for an exhaust outlet to warm up? What water and ambient temperatures do you boys run in? We have no experience of cold conditions here (current ambient is 28 and sea temp is 24 centrigade), but that length of time sounds dubious to me.<br /><br />Ciao

 

[daveswaves]

Re: Smokey Exhaust (Evinrude 30hp)

Might be time to decarb as well, a sticky ring would let oil by and may stop after extended running. Lets all go fishing in Malta!

 

[zdmaster2k]

Re: Smokey Exhaust (Evinrude 30hp)

JB, I promise I will get the model numbers tomorrow!! We run on an old gravel pit, freshwater. Just recently air temperature has been hovering around the 15 celsius mark. It does take a long time to stop, I often take the boat for a burn and give the tank a shake but to no avail...G DANE is right, the idle exhaust is warm. Thanks for the recommendation on the fuel mix too JB, i'll see that's enacted. I wish I was operating in Malta.......

 

[zdmaster2k]

Re: Smokey Exhaust (Evinrude 30hp)

Okay, here we go! BE30BALCO so that's 1985 right? I was running on JB's recommended 1:50 mix today, far smoother and quieter. The exhaust wasn't too bad until I'd been at WOT for a few minutes, after that there was loads of smoke/steam, hope that and the model number helps

 

[zdmaster2k]

Re: Smokey Exhaust (Evinrude 30hp)

^

 

[ED21]

Re: Smokey Exhaust (Evinrude 30hp)

I wonder if you have a head gasket leak that is letting in enough water to steam, even though it still runs okay.<br />After running an hour or so it finally swells up enough to stop.

 

[fireman57]

Re: Smokey Exhaust (Evinrude 30hp)

After running for five minutes or so with the steam/smoke stop and pull your plugs and see how they are burning. I'm with Ed you may have a bad head gasket and a washed plug would pretty much confirm it.