96 evinrude 35hp White Milky out the Prop Exhaust

[lenwoodbluz]

Hello there everyone. I am just writing to get a confirmation on some advice that I am planning on trying.

I took the cowling off of my 35hp evinrude (3cyl) while on the water. The latch ripped the sparkplug wire off the coil. the plug and the wire were ripped apart.

I had to get the boat off the rough water to get it closer to the landing so we could paddle. I ran the motor on 2 cylinders for a couple of minutes. and then it began to run really rough. So I stopped running it.

I understand that this could have ruined the coil and worse yet, it could have ruined the Power pack.

when I got home, I found out how easy it was to fix the sparkplug wire (could have used that info on the water).
I reattached the wire and tried starting it up with the water hose attachment. she still ran rough. lots of smoke.

I checked the spark on the three plugs and all three still fire. (thank god because the power pack is over 300 bucks.

I noticed that when I ran it again for a while, the engine started to run smoother but there was a white milky discharge in my prop and around my prop.

the advice I received was that my motor is still trying to burn off the oil buildup from running it on two cylinders. and also that when you run it in the driveway, you can't get a high enough rev to clean the system out. I was told to bring it to the lake and give it a good run.

I have cleaned the sparkplugs because they were wet with oil and when I checkd them after my last driveway run they were wet again but not nearly as bad as before.

so my question is this. Is running my boat in the water likely to fix and clean my problem, or will it damage everything and send me to the poor house.

one last question. I have had places in town tell me two different sparkplug models for my motor. does anyone have a good site where I can look up the proper plug for a 1997 35hp evinrude 3cyl.

thanks a ton in advance

lenwoodbluz

[StianM]

I just like to say that running on less than all cylinders should newer be done.
The pulses from the detonation is calculated befour the crank is designed, running on a other number off cylinders then the crank is designed for can lead to it breaking.

I newer payed mutch atention to spark plugs, if the length is ok I use them and can't recal I ever had a problem.

[marshmat]

You can download the engine's parts list and diagrams from Bombardier at http://www.evinrude.com/en-US/Access...re/?popup=true , you have to register with an email but they do keep a pretty decent stash of old literature. Can always phone them if you can't find the spark plug specs there.
I would replace the plug wires before taking it out; sure you were able to patch the broken one back together but I still wouldn't trust it not to fail. I see no reason why you shouldn't take it out on the water and see if it gets any better; the explanation you were given (one cylinder and its exhaust line saturated with oil) makes sense.
Stian's right, though.... if you lose a cylinder again, limping home on the remaining two isn't generally a good idea unless absolutely necessary to get out of immediate danger. If your motor is like other 'Rudes of its vintage, it's built well enough to handle this without damage for a short while, but I would avoid running on two cylinders if possible.

[Frosty]

Spark plugs are very important.

The numbers on them are equally as important .

The fact that they fit in the hole is imaterial.

All the numbers mean some thing and those who have trouble with them should learn what the numbers mean.

The heat range is very important, especially on a 2 stroke. Some of the advice on this forum is un believable.

Put a proper set of plugs in it and give it a run --in the water not with earmuffs on,---like it was meant to do.

[Bergalia]

Originally Posted by jack frost

give it a run --in the water not with earmuffs on,---.

Yes whatever you do - do not fit earmuffs to the engine...

But Jack is right. The heat value of the plug is essential for optimum running - not only for economy and correct ignition, but also (too hot) to avoid damage to the top end (burnt valves/sleeves and piston crowns). Alternatively (too cold) sluggish combustion and a build up of unburnt fuel reaching the exhaust and even finding its way into the sump and thinning the lubricant - even worse reaching a temperature where it explodes....

[Frosty]

No --Im sorry but the heat range of a spark plug does not effect cylinder temperature.

The heat range of the plug is directly relative to the heat of the operation of the plug.

In other words it is the temperature of the plug and its operational range whilst working.

For instance a fouling plug --Whilst the cylinder is obviously suffering from other defects. The engine will benefit the fitting of a hotter plug. This will increase the plugs tempeature and reduce the fouling effect by being able to burn off the oil or fuel from its firing centre.

The numbers of a spark plug is very interesting and not complicated.

I urge you to google it and see what all the numbers mean.

If you look down into a hot plug and a cold plug you will see a difference in the length of the ceramics. A short ceramic is a hot plug insulating the heat from the clylinders cooling system and consiquently runnining in a hotter state.

[Bergalia]

I won't argue Jack. You obviously have the experience - mine only comes from way back with the old MG TC in which the 'handbook' gave a warning similar to the one I offered above. But I've little or no experience with the 'smelly' bits attached to small boats - more used to big diesels (so what do I know about spark plugs).
Lenwood - ignore me - listen to jackfrost..

[lenwoodbluz]

Wow. thanks a ton everyone. I found the proper sparkplug online and I'm ready to go today. I really appreciate all the help. I think I'll be reading this forum a lot.

As far as running on two cyl...........never again. I'm hoping to have lucked out and had no damage....but that would be a first for me...He He He

thanks everyone

[StianM]

My only experience with spark plugds is that a coolder plug don't melt on high rpm high powered home modefyed motorbike engines.

I really can't understand why since increased ceramics should isolate the coolder plug from the cooling system. Maybe it's cooled bether by the savanging without geting new hear from the cooling system

[StianM]

The operating temperature of a spark plug is the actual physical temperature at the tip of the spark plug within the running engine. This is determined by a number of factors, but primarily the actual temperature within the combustion chamber. There is no direct relationship between the actual operating temperature of the spark plug and spark voltage. However, the level of torque currently being produced by the engine will strongly influence spark plug operating temperature because the maximum temperature and pressure occurs when the engine is operating near peak torque output (torque and RPM directly determine the power output). The temperature of the insulator responds to the thermal conditions it is exposed to in the combustion chamber but not vice versa. If the tip of the spark plug is too hot it can cause pre-ignition leading to detonation/knocking and damage may occur. If it is too cold, electrically conductive deposits may form on the insulator causing a loss of spark energy or the actual shorting-out of the spark current.

A spark plug is said to be "hot" if it is a better heat insulator, keeping more heat in the tip of the spark plug. A spark plug is said to be "cold" if it can conduct more heat out of the spark plug tip and lower the tip's temperature. Whether a spark plug is "hot" or "cold" is known as the heat range of the spark plug. The heat range of a spark plug is typically specified as a number, with some manufacturers using ascending numbers for hotter plugs and others doing the opposite, using descending numbers for hotter plugs.

The heat range of a spark plug (i.e. in scientific terms its thermal conductivity characteristics) is affected by the construction of the spark plug: the types of materials used, the length of insulator and the surface area of the plug exposed within the combustion chamber. For normal use, the selection of a spark plug heat range is a balance between keeping the tip hot enough at idle to prevent fouling and cold enough at maximum power to prevent pre-ignition leading to engine knocking. By examining "hotter" and "cooler" spark plugs of the same manufacturer side by side, the principle involved can be very clearly seen; the cooler plugs have more substantial ceramic insulators filling the gap between the center electrode and the shell, effectively carrying off the heat, while the hotter plugs have less ceramic material, so that the tip is more isolated from the body of the plug and retains heat better.

Heat from the combustion chamber escapes through the exhaust gases, the side walls of the cylinder and the spark plug itself. The heat range of a spark plug has only a minute effect on combustion chamber and overall engine temperature. A cold plug will not materially cool down an engine's running temperature. (Too hot of a plug may, however, indirectly lead to a runaway pre-ignition condition that can increase engine temperature.) Rather, the main effect of a "hot" or "cold" plug is to affect the temperature of the tip of the spark plug.

It was common before the modern era of computerized fuel injection to specify at least a couple of different heat ranges for plugs for an automobile engine; a hotter plug for cars which were mostly driven mildly around the city, and a colder plug for sustained high speed highway use. This practice has, however, largely become obsolete now that cars' fuel/air mixtures and cylinder temperatures are maintained within a narrow range, for purposes of limiting emissions. Racing engines, however, still benefit from picking a proper plug heat range. Very old racing engines will sometimes have two sets of plugs, one just for starting and another to be installed once the engine is warmed up, for actually driving the car.

I understand bether now, but

By examining "hotter" and "cooler" spark plugs of the same manufacturer side by side, the principle involved can be very clearly seen; the cooler plugs have more substantial ceramic insulators filling the gap between the center electrode and the shell, effectively carrying off the heat, while the hotter plugs have less ceramic material, so that the tip is more isolated from the body of the plug and retains heat better.

this got to be wrong

More ceramic material would in my opinion mean it carry less hear since it's insulated bether. I have to sleep on this one a litle

[redtech]

lenwoodbluz, what good verity of answers to the question
first if on the water you do what you have to do three or two cylinders
next this is a very good motor thats been tested many times by many people
if you're nursing it to the dock thats ok
now that white milky oil coming from the prop is just unburned oil mixed with water in the exhaust housing this is from running on two instead of three as you use the boat it will go away

spark plugs??????
use the champs desinged for this engine and don't change heat ranges
not going to argue about the plugs and how they work just use the right one