90 merc smoking

[franger]

i have a 2003 90hp merc 2 stroke which runs out decent but i'm unsure as to whether it is smoking excessively. lots of smoke on start up (cold or hot) or at low speed. seems to be using a lot of oil, 30 mile run used approx. 1/2 - 3/4 quart. i am using motomaster formula 1 oil which is TC-W3 rated, should i be using merc branded oil and can this contributing to the smoking/consuption issue?

 

[Silvertip]

Re: 90 merc smoking

To determine if you are using too much oil, mark the oil level on the tank with a felt pen or piece of tape. Add one or two pints of oil and mark the level again. Now run six or 12 gallons of fuel through the engine. Depending on the how much oil you added the level should be half way (6 gallons) or at the lower mark (12 gallons). If its lower than the marks, it is indeed oiling too heavy and the excess smoke would be the result of that. If oil consumption is normal or near normal, then you might try a different oil. It is not necessary to use Merc oil. Semi-synthetics and full-synthetics reduce smoke considerably.

 

[franger]

Re: 90 merc smoking

ttt

 

[quebec#1]

Re: 90 merc smoking

Im new to the merc world, Always been a omc fan, Anyways i bought another boat with an older (1986 MERC 150 XR2) i seem to have the same problem, It smokes alot at idle , at cruising speeds 0 to 1500 rpms it loads up and smokes alot, at higher speeds after the boat planes out it runs great. I was using the merc injection oil and now im using the shell outboard oil from canadian tire and its still smoking like a bastard.
I finaly brought it to the dealer and he said thier was a way to turn down the oil pump or make some sort of adjustment to lean it out a little.
Im cant wait to see if the problem is fixed, maybe you can turn the pump down on yours as well.

 

[steam_mill]

Re: 90 merc smoking

i have a 2003 90hp merc 2 stroke which runs out decent but i'm unsure as to whether it is smoking excessively. lots of smoke on start up (cold or hot) or at low speed. seems to be using a lot of oil, 30 mile run used approx. 1/2 - 3/4 quart. i am using motomaster formula 1 oil which is TC-W3 rated, should i be using merc branded oil and can this contributing to the smoking/consuption issue?

I have the same motor and same year. Based on your oil consumption, I would assume you used somewhere between 8 to 10 U.S. gallons of gas? That would be about right for a 30 mile run.

This consumption would be 50:1 which is bang on.

I get a bit of smoking at start up also. Remember, if you are running in humid conditions (like in Ontario), you are going to see the smoke.

 

[franger]

Re: 90 merc smoking

thanks for the replies. as for steam_mill's question, the gas tank is 88L - 20 us gal and i'm getting about 100-120 mi per tank (unsientific, i know) and would use the better part of the oil reservoir (approx 4L), down to the low oil buzzer . that would put me closer to 25:1

 

[quebec#1]

Re: 90 merc smoking

The thing is are you smoking excessively during start ups and and slow speeds even after the engine is warmed up ? Mine is and in a long no wake zone anyone behind me gets smoked out. Its not crazy amounts but i dont think its normal. It also runs a little rough at slow sppeds but great once the boat planes out. I will keep you posted on what the dealer did to resolve the problem .

 

[steam_mill]

Re: 90 merc smoking

Not to nit pick but if you are using 1/2 quart for 30 miles, then you will use 1.67 quarts for 100 miles. If you are using 3/4 quart for 30 miles, then you will use 2.5 quarts for 100 miles. Are you saying that for 100 mile trip, you are burning through 4 quarts of oil?

Unless the system is adding more oil as it heats up or something like that, I don't see how there could be such variability.

At 1/2 quart for 30 miles, that is 48:1. 2.5 quarts for 30 miles is 32:1.

If I recall properly, the mercury system does vary the oil rate as speed increases. I think it is 100:1 at idle and 50:1 at WOT.

Hope this helps.

Joe

 

[franger]

Re: 90 merc smoking

starting to sound very much like quebec#1's symptoms, appreciate the update when you get her back. talked to a marine mechanic and he verified steam mills 100:1 at idle and 50:1 at WOT claim. you were right to nit pick my math, my numbers were guesstimates at best. i need to top off both oil and gas and refill end of the day to determine my oil usage more accurately. again, thanks for the feedback.

 

[quebec#1]

Re: 90 merc smoking

I just called up the dealer a few minutes ago. He said the boat is ready, He said they turned down the oil adjustment ? and changed the fuelpump diaghram. I will keep you posted once i get the boat back if they resolved the problem.

 

[quebec#1]

Re: 90 merc smoking

I got the boat back and ahve the same problem, A little while later i lost power and couldnt get the boat to plane.
I check to see if all cylinders had a spark and all three on the right hand side were down so back to the dealer once again !
I talk to the dealer today and he said the stator is the problem and was probaly the cause of the smoke problem at slow speeds because the right cylinders didnt have a good spark and werent burning the fuel and gas off.

 

[franger]

Re: 90 merc smoking

quebec#1
keep me posted, hope they're not leading you down the garden path!

 

[quebec#1]

Re: 90 merc smoking

quebec#1
keep me posted, hope they're not leading you down the garden path!

Me too !

 

[quebec#1]

Re: 90 merc smoking

I got the boat back today, they replaced the stator and switch box and all seems fine it even seems to have way more power all around.
Also it dosent seem to load up and smoke like before, I persume the problem is solved !