Peter MacWilliam wrote:

Hi Fleetwin,

No, to me, this does appear to be a Yachtwin 6HP, according to what is written on the cover, which I will include pics of.  It does say both “yachtwin” and “6” on the cover, which I believe means it is a 6HP.  But please explain if that is not correct.

thanks,

Peter

OK, you are right…. But, this is more like a 1988 6hp Yachtwin….

These are nice engines, but they do have a few engineering flaws that you need to look at, especially if this engine was used in salt water.

So, let’s start with the simple checks again.  Check compression, then drain the gear lube.  There are two large drain screws to remove before you can determine gear lube condition, let it all drain into a clean pan.  Gear lube for these engines is normally pretty dark, and may even smell a bit.  Milky gear lube or raw water draining out spells trouble.  If the gear lube seems “OK”, then it must be refilled from the bottom hole until it spills out from the top hole.  Make sure each drain screw has one and only one plastic sealing washer, the washer(s) may be stuck in the housing instead of coming out with the screws.

If compression is OK, check for spark, but remember that the little safety switch/clip/lanyard must be in place on the throttle handle, or there won’t be any spark.

Now, you are ready to attempt to start the engine, ignore the idiotic 100:1 mixing instructions on the lower pan, mix at 50:1 using a good TCW3 outboard oil.

This engine uses a “primer” instead of a choke, and it is a pain to understand and use properly.  The primer has three positions:  off/warm up/prime.  Once the fuel bulb is pumped up, pull the primer all the way out a few times to force fuel into the intake manifold.  Once the engine is running OK, you can push the primer all the way back in to the off position.  The engine will run too rich and eventually stall if the primer is left in the middle/warm up position.

Needless to say, the engine must be deep in the water in order for the water pump to work and not get damaged.   Looks for a decent discharge from the cooling telltale indicator nipple once the engine is running.

Don’t get me wrong, I like these engines, but they have some terrible flaws that you have to look out for.

The modular/plastic carburetor gets messed up easily, there is a little rubber idle pick up hose that loves to disintegrate.  The plastic top cover and bowl are easily broken and expensive to replace.

The poor gearcase design suffers in jumping out of gear issues, especially when reverse gear is used alot, like on sailboats or tenders.  No real way of knowing if there is an issue until you have the engine on a boat and run it at high RPM under load.

These engines are known for driveshaft splines get stuck/rusted into the crank splines.  Needless to say, you won’t know if this is an issue on your engine until you attempt to remove the gearcase.   Needless to say, this is more of an issue on engines used in salt water.

Finally, these engines are subject to an overheat condition caused by a poorly designed upper water tube grommet that gets crushed and blocks water flow into the powerhead.  Again, this is more of an issue on engines used in salt water.

So, let us know where you stand with this engine.  Hard to understand why I like these engines but I do, regardless of the terrible issues that plague them.

Peter MacWilliam wrote:

Hi Fleetwin,

are these the “2 large flat head screws” you referred to?  (See attached pic)

No.  I am referring to the two large flat head fill/drain/vent screws on the gearcase.  One is below the rounded bullet, the other is about the horizontal plate above the propeller.  This model does not have the phillips screw I warned about, so not to worry.

Peter MacWilliam wrote:

I appreciate the advice you folks have offered but when I said I am a novice, I mean a total novice.  So what you’ve written to me and the link I looked at assume I have some knowledge, which I don’t.  I’ve attached a pic of my outboard motor.  Which nut or screw would you recommend I turn first?  I expect to take it entirely apart.  I am pretty sure it needs the carb redone.  One way or the other, I will figure this out, and once I get going I will begin to understand what next step to take but right now, I have no idea.

OK, the engine looks complete and unmolested, doesn’t show any obvious signs of overheat, which is a great sign indeed.  I see an external power pack, so feel confident that it is an 86-88 model, 89 models used the “UFI” system with the powerpack stuffed under the flywheel.    Your engine does have the alternator as well.

Post more side view pictures of the complete engine so we can determine the shaft length.  The only major difference between some of these models is that the 1988 models used the “ball shift” gearcase instead of the conventional clutch dog style.

Again, try to post of picture of the black ID tag which is usually on the left stern bracket, it will have the model and serial number.  The powerhead ID tag will only have the serial number, can’t determine much from that.