is smoke to be expected on '78 merc

[Guzman]

Just bought a '78 champion bass boat with a 90hp mercury outboard motor. My question really has to do with inexperience with boats.

The motor sounds really loud. a little louder than a leaf blower. is this normal?
Smoke coming out of propeller area... again, this is a 1978 boat. Is this to be expected?

Do these motors require oil or is the oil you mixed in with the gas enough.

Boat came with spot for three batteries. Why so many? don't boats charge batteries like a car or do I have to charge them after each use?

 

[j_martin]

Re: is smoke to be expected on '78 merc

I hope you're not running the motor without cooling water. If you have, you already need a new water pump impellor or more.

Most of the noise is buried in the water through the hub of the propellor. Oil is mixed with the fuel, so smoke is normal, especially cold and slow.

Must be a fishing boat. 1 battery is for the motor cranking, and if the motor is normal it will keep it up. The other 2 are for a trolling motor, and they have to be recharged after each use. Many bass boats have a charger built into the boat.

My main suggestion is that you get educated before you wreck your new toy.

 

[Guzman]

Re: is smoke to be expected on '78 merc

Thanks for your reply. You are absolutely right, I don't want to ruin my new toy due to inexperience. It is hard finding information, especially on a boat that old. I ran the engine in neutral for at most 1 minute.

 

[NCSU4x4]

Re: is smoke to be expected on '78 merc

You prolly should get that water pump impeller replaced if you ran it out of the water. You may be kicking yourself.. but not as hard as you will be if the pump doesn't move enough water and you cook the motor.

 

[Texasmark]

Re: is smoke to be expected on '78 merc

Yes on adding oil. That is a 2 cycle engine and requires pre-mix....let's see, 78 is 50:1 that's 16 oz can of marine 2 cycle oil (TCW or TCWI or II or III....look on the container for the certification) to 6 gallons of regular (87 octane R+M/2) gasoline. Gotta remember the oil. Miss it once and you can trash your engine.

1 minute isn't that long but not good to run without water to engine. No telling how old your impeller (rubber blade) in the water pump, so replacing it is probably a good idea regardless. Lots of how to's here in the archives.

As stated, smoke is normal as this is a 2 cycle engine which burns oil with the gas, hence smoke.....when you get the muffs on it (muffs attach to your lower unit for running from a garden hose for cooling) then water will come out with the smoke from the prop.

Great idea to keep the ignition key off till you understand what you can hurt by what you do. Get with someone else who has a boat if you can and pick their brain.

Older Mercs were very loud. One of the things the other guys (Johnson-Evinrude) harped on was how quiet theirs was and how loud Mercs were...........course that's probably because the Merc was in front of them and obviously it is noisier when you are ...............getting beat. Ha!....;no really, the OMC engines were a lot quieter for several reasons.

HTH and good luck,

Mark

 

[SeaKaye12]

Re: is smoke to be expected on '78 merc

Where are you Guzman?

I saw a Champion with a 90 at the Cars4Causes charity last week. Were you the winning bidder?

If so; you live pretty close to me maybe? I have a 85HP Merc and would be happy to walk you through the basics. I'm not a mechanic but with the help of lks here I've been able to do anything that my Merc needed so far...

Thanks for reading, Chuck