OUTBOARD FREQUENTLY ASKED QUESTIONS

1. Off season is warm here. Do I need to winterize ?
2. What ratio of oil do I mix with the gas?
3. My manufacturer recommends 100:1 mix. Is that enough oil?
4. My motor runs rough. Should I add an additive to the gas to clean the carburetor?
5. What can I do to make this outfit a little faster?
6. My motor "clunks" when I am going ahead at higher speeds. Acts just like I hit something in the water!
7. My motor fouls the recommended spark plugs constantly. What do I do?
8. Black oil is leaking out of my lower unit by the propeller and dripping off. Do I need a gear case reseal?
9. I moor my boat in the water. I notice that its way slower now than it was when launched. I need a tune-up!
10. I have great spark at the plugs, but I have a bad miss.
11. I have great spark cranking my motor with the plugs out, but it goes away when they are installed. What's wrong?
12. I get a shock from my control box!
13. How often should I replace my water pump?
14. I have a lot of gas left over from last season. Is it OK to use it this year?
15. I have a 2 cylinder OMC outboard with externally mounted coils and breaker points. I have weird spark problems. What can I do?
16. Where can I get a copy of a service manual for my motor?
17. I don't know what year outboard motor I have. Can you tell me how to find out?
18. I have an older outboard with higher compression. Should I burn PREMIUM gas?

1. Off season is warm here. Do I need to winterize? top
You certainly do! Off-season storage in a warm, and possibly resultant humid climate is especially hard on unused equipment. Hawaii is the worst! See my storage preparation page for details on how to store your rig for the off-season.

2. What ratio of oil do I mix with the gas? top
If you have an owners manual, look there to see what the manufacturer recommends. If you have no clue, almost any motor will perform just fine on a 24:1 ratio. Any motor built after around 1965 will run just fine on 50:1 mix. For this ratio, I strongly recommend a MAJOR MOTOR MANUFACTURER TCW 3 lubricant. Don't use aftermarket oils. EXCEPTION! 100:1. See question 3 below.

3. My manufacturer recommends 100:1 mix. Is that enough oil? top
Absolutely NOT!    DON'T DO IT!     That's plenty to lubricate the motor under IDEAL conditions with a HIGH QUALITY 2 cycle lubricant. The problem comes after use - the lack of adequate oil for storage on the internal bearings, rings, and cylinder walls leaves your motor wide open to IMMEDIATE internal damage, and shortened service life.

4. My motor runs rough. Should I add an additive to the gas to clean the carburetor? top
Only BOMBARDIER (Evinrude/Johnson)'s "Fuel System Cleaner" is specifically made to do this safely (this presumes the passages & jets are not totally clogged). There is no other known additive that you can add to the gas mix that will clean an outboard carburetor. Automotive-type panaceas contain strong solvents and cleaners that will damage or destroy the components of the outboard fuel system. BOMBARDIER (Evinrude/Johnson) also makes a product that will keep a clean system clean - "2+4" fuel conditioner. I am certain there are equivalent products from the other motor manufacturers as well. If you do have a "dirty" carburetor, the only sure cure is to disassemble it and use approved cleaners to de-scrozz it.

5. What can I do to make this outfit a little faster? top
That opens a can of very large worms! The best way to go faster is to get a bigger motor. As to increasing the performance of any given rig, it is essential that you contact me for a consultation, as every girl's different.

6. My motor "clunks" when I am going ahead at higher speeds. Acts just like I hit something in the water! top
This is a shifter engagement problem caused by various maladies on different makes and models. If an adjustment of the linkages to favor forward doesn't help, it will require a trip to the motor doctor.

7. My motor fouls the recommended spark plugs constantly. What do I do? top
First thing to do is make sure the thermostat is working and the motor is running at the correct temperature. If your motor is cool or just warm to the touch, it is too cold and will foul plugs. If the cooling system is all in order, try the next hotter plug. The manufacturer's recommendation is usually to the conservative side and takes into consideration the extended WOT use and abuse some put their motors through.

8. Black oil is leaking out of my lower unit by the propeller and dripping off. Do I need a gear case reseal? top
Probably not. What you are seeing is residual oil draining down out of the exhaust system. Especially noticeable if you ran the motor for awhile at lower speeds in colder water before you removed it from the water. It is a good idea to check the gear case fluid after you use the motor to see what the oil looks like. It should be from the color of honey to weak coffee. If it is creamy white and foamy, there is water in it. (Some murkiness is normal over time.) Worse is black, foul smelling and/or under pressure. This is dirty, burned lube and should be changed immediately. If you see any metallic colors floating around in the oil, you got troubles, Bunky!

9. I moor my boat in the water. I notice that its way slower now than it was when launched. I need a tune-up! top
Before you drag it to the shop, check several things. First, does the bottom of your boat look like a Caesar salad? Marine growth can be prolific, and will cost you a large percentage. In saltwater, the buggies will start growing in 3 - 4 days! Second - is the inner hull of your boat full of water? if the flotation area under the flat floor is loaded, the extra ton of water will slow ya down. Third - how's the propeller? A couple of dingies in the wrong place will cost miles per hour! The outer 10% of the blades does 90% of the work.

10. I have great spark at the plugs, but I have a bad miss. top
Here I usually find a case of a weak coil or dirty breaker points, leaky condensers, etc. What looks good on a set of plugs laid on the block is not indicative of a healthy ignition system. The spark from a modern electronic system should consistently jump a 3/8ths to 1/2" gap. The older Battery CD motors are especially hard on coils, so much so that you should gap the plugs down to .030 or less and replace the coil whenever there is the least misfire.

11. I have great spark cranking my motor with the plugs out, but it goes away when they are installed. What's wrong? top
The first question, is the motor cranking fast enough to properly energize the ignition system? The average magneto energized CD ignition needs at least 600 rpm cranking to work. Check the BATTERY, the CABLES, the SOLENOID, the STARTER. If they are all OK, look at the ignition STATOR, SENSOR and the COIL(S) OMC V4 motors from 1973 thru 1977 have a problem with weak sensor coils. New ones are EX-PENSIVE! Look around at the local O/B junk shop for used ones, old 1.5 volt coils are white,the improved 3 volt ones are reddish in color.

12. I get a shock from my control box! top
You have a leak in the high voltage leads in your wiring system, allowing the primary ignition voltage to leak to ground (you, in this case). These systems can create over 300 Volts AC, more than your house wiring. Disconnect the shorting lead(s) at the powerpack, and if the shock disappears, identify the bad wiring or switch, and replace. This can also cause the problems in Qs #10 & 11.

13. How often should I replace my water pump? top
The modern outboard's water pump housings are stainless steel, impellers are of compounds that do not rot or deteriorate in salt water. With care will last a long time. There ARE 2 enemies. first - NEVER Start the motor dry - not even for a "couple of seconds". Water lubricates the pump, and a dry impeller is like a locked up set of tires in a panic stop! The pump will self-destruct. Second - abrasion - does the water you boat in have a lot of silt of murk in it? Do you hit a lot of muddy bars and sandy beaches? Ask around to see how frequently this environment in your area eats pumps and act accordingly. You should replace this impeller every couple of years in any case and definitely in an engine that has seen extended storage.

14. I have a lot of gas left over from last season. Is it OK to use it This year? top
IF you added a fuel stabilizer and IF you filled the tank up when you put away the boat, it should be OK. If you have a high performance ski or Bass boat, I would advise at least half the old gas be siphoned out and used in your tow vehicle, replace it with mid-grade fuel. In fact, use mid-grade in any motor over 50 HP and NEVER use 87 octane, its not fit for your lawn mower, let alone a $10,000.00 outboard. Also see question 19. A relevant article on fuel can be found HERE

15. I have a 2 cylinder OMC outboard with externally mounted coils and breaker points. I have weird spark problems. What can I do? top
Make sure the stator plate (Where the points and condensers are mounted) is not wobbly on the top of the block. Excessive sideplay will make it impossible for the point gap to be properly adjusted. Do a continuity test on the 2 blue wires that connect to the coils to make sure they do not have a wire break inside the insulation. (Stretch 'em!) I've seen numerous instances of this failure. The points in This system must be SCRUPULOUSLY clean. The voltage through these is so low, they tend to get dirty and malfunction. The problem is made worse in that the charge coil grounds through the opposite set of points to the cylinder being triggered. A weak spark on #1 is often caused by defective points on #2!

16. Where can I get a copy of a service manual for my motor? top
Many local libraries carry these. OMC has model-specific factory manuals by year available through MASTERTECH that are excellent. ALL OMC service, owners manuals and parts lists are available thru MASTERTECH, CLICK HERE to order these on line. We also have old MERCURY manuals, 3 different ones HERE that cover models thru 1978. For later Merc, Force and Chrysler literature ORDER FORM . For the new SELOC aftermarket manuals on HONDA, SUZUKI and YAMAHA IMPORTS will take you there. If you want a comprehensive manual, or just have interest in reading about boats and motors check out my AVAILABLE BOOKS PAGE and order them right here, online.

MERCURY AND US BUILT MARINER OVER 40 HP
For motors from early 60's thru 1999.