Excess exhaust smoke?

[lisfisher]

Last two trips out my engine has been blowing a bit more smoke than normal , usually the majority of it blows out upon start up and the first few minutes of ideling.My engine is oil-injected . It does run good though and starts right up first crank. Do I need a carb adjustment?

Also , is there some sort of propeller condition , similiar to cavitation , where you feel like something is "slipping"? Yesterday on the water the seas were pretty rough ,currents and wind were strong and we had tons of weight in the stern , so we were very stern heavy.Upon trying to pick up speed,she had a tough time,and a couple times I felt a "slip" ,meaning the rpm's revved up but the boat didn't want to move for a second or two. Never experienced this and I'm thinking it had something to do with the stern being too heavy and the bow too high? Also , there was a good size water "fountain" coming almost straight up toward the backside of the cowl when trying to build up speed.

 

[tashasdaddy]

Re: Excess exhaust smoke?

you don't state what engine you have or the age, your slipping is probably due to an unsafe loading situation you mentioned. the boat was not able to move forward enough to get enough water to grab. you were a$$ heavy.

 

[lisfisher]

Re: Excess exhaust smoke?

that's what I figured . Plus we had a full tank of gas { 22 gall } which is underneath the floor in the stern area. The engine is a 1995 75 HP Mercury.

 

[Texasmark]

Re: Excess exhaust smoke?

The water spout is normal for an arse heavy boat in the (speeed buildup) trough between sitting and planing out. Had you had more power, or the water not have been so rough, you could probably have planed out at which time the water spout would have moved farther out behind the boat and would have become smaller as it did.

The skipping could be one of two things. With all that stress on the prop, indicated by what you said on loading and the water spout, your prop blade to prop shaft was under max stress. This could have caused the rubber (slip clutch) hub to slip periodically. Very possible.

Otherwise, you could have gotten waves and things just right under the boat, and ventilated where the prop sucked air and as a result didn't provide propulsion till the water flow to it cleared out.

The smoking I'm going to guestimate is engine congestion caused by you lugging it as you just said. I suggest a thorough decarbing (search herein) and then keeping Sea Foam in your fuel tank. Then if this arse heavy condition is your norm, you might invest in smart tabs. Lotta info on here about satisfied folks using them for problems like you mentioned.

You may be pleasantly surprised.

HTH

Mark

 

[lisfisher]

Re: Excess exhaust smoke?

The excess smoke has happened on the last two trips.The only lugging we did was last night , which was rare that we bring that much gear. The trip before last was a normal load and flat seas but she still smoked more than normal. Seems to have started as soon as I changed octanes. I used to put in 87 octane but after reading about octane loss , water in the gas and detonation I started putting in 89 octane. Not sure if that has anything at all to do with it but it did start after that.

 

[tashasdaddy]

Re: Excess exhaust smoke?

has it ever been dercarb, with seafoam deep creep. could be excess carbon burning off.

 

[lisfisher]

Re: Excess exhaust smoke?

No , never decarbed and I'm not really familiar with the process. This also started after I made a longer than usual run about 10 miles out. I'm wondering if having it at near WOT for 20 minutes could have tweaked the engine somehow?