1987 200 ETXH - Water Pump Questions from a newb

[ryanmaker]

I recently purchased a 1982 SeaCraft 20 with a 1987 Yamaha 200 ETXH (6G6). This is my first "big boat" and largest outboard.

last weekend I went to start it after it had been sitting for a month or two. Got it running and noticed no water coming out of tell tail (pisser), I turned the key off, and motor kept running, pulled kill lanyard...kept running, shut batteries off...kept running, finally pulled fuel line and eventually stopped. After some diagnosing of the harness etc.. turns out most likely the key switch. This however, is not the issue just the back story.

Figured I would start with water pump. I dropped the lower unit to replace water pump...easy...till I got to the woodruff key, dremel and a couple hours and finally got it out. I went to get new water pump kit, there seem to be several that could work on this motor. Ended up at West Marine with two parts...Sierra 18-3396-1 and 18-3311...here is where it gets weird...the 3311 is what the 'computer" says is the right part (problem was the only kit in stock was missing the actual impeller)...I somehow found the 18-3396-1 on their website and took a look at it. Side-by-side comparison appears that all parts are identical in each kit with the exception of the diameter of the hole in the tin cup, the 3311 is narrower that the 3396-1. I brought my old pump in to compare and the one I took off my motor matches the diameter of the 3396-1 (which according to the computer and other resources) technically inst the one for my motor.

So now I left asking a couple questions...
1. is the lower unit from a different motor?
2. Did someone put the wrong part in at some point in the past?
3. Did the manufacturer replace parts/part #'s over time.
4. If I go with the one that matches what I took off will there be an issue you could think of?
5. The hole diameter shouldn't matter as its only to get over/around shaft?

I also think there may be some "pieces" missing, when I disassembled there was not ring or washer/seal around drive shaft entering into water pump housing..I think there should be..can anyone confirm?

Sorry for the long winded story...any help/insight would be appreciated.

Ryan

[boscoe99]

One problem with using aftermarket parts is that they might not always fit correctly. Unless one is very familiar with a model and will know exactly what other stuff can fit and what cannot fit it might be desirable to stick with Yamaha parts.

You can follow the Yamaha parts diagram to ensure that all parts are there and correctly installed.

Carefully inspect the lower unit that you have. Look into all nooks and crannies and see what markings you can find. You are looking for 6G5 if you can find it. That would indicate to me that it has the originally designed lower unit on the motor.

Yes, all manufacturers replace stuff over time. With Yamaha you can see updated parts numbers in their parts catalog. With non-OEM I don't know how you can tell.

[ryanmaker]

Thanks for the reply...

I have all the parts indicated in the diagram. Watching some videos, and keep seeing a nylon spacer and stainless collar, with a set of three washers directly above the impeller. These were not present on my drive shaft when I took apart.

Where abouts should I look for the markings you mentioned.

as far as the aftermarket parts...what I brought home (18-3396-1) matches what I took off. If i go with the actual factory part number I end up with a chrome cup (#15 in diagram) with a smaller diameter hole than what I removed. I have not checked to see if the smaller diameter part will fit over shaft..I assume it would...and I cannot think of any reason the difference in the diameter would effect performance/operation.

from the image below, I do not see and collars/washers/nylon spacer that would go onto drive shaft.

I will keep researching, thanks for your input...any additional info is welcomed.

Ryan

[boscoe99]

Some lower units use wave washers and spacers and others do not. You may be looking for something that is not there. Is not supposed to be there.

A Yamaha is not a Yamaha is not a Yamaha. You can look on your model for an electric fuel pump. You won't find one. It is not supposed to be there.

Look down into the cavities at the top of the lower unit when it is removed from the motor.

[ryanmaker]

I spoke with a tech at Sierra as well as some boat buddies. Consensus is that the difference in the diameter on the chrome cap (#15 in diagram) will have no bearing on performance or operation..probably just a change in the part over time...

In regards to the nylon/SS collar, I now do not believe it was ever there to begin with, so as you said...I was looking for something that is not there.

I'm gonna put it back together today and see what happens.

Thanks for all your help!!

Ryan

[Jason2tpa]

I spoke with a tech at Sierra as well as some boat buddies. Consensus is that the difference in the diameter on the chrome cap (#15 in diagram) will have no bearing on performance or operation..probably just a change in the part over time...

...So says the sierra rep and your boat buddies. I'm just spitballing here, but this sierra rep is just reading off their computer that the part # matches your engine model/year. Whereas if you spoke with an authorized yamaha parts dealer, they are thoroughly informed with pertinent yamaha info concerning your model/year. And with an engine as old as the one you've got, my guess is most of the parts have been superseded many times over.

Thus, I reinforce boscoe's words of wisdom:

One problem with using aftermarket parts is that they might not always fit correctly. Unless one is very familiar with a model and will know exactly what other stuff can fit and what cannot fit it might be desirable to stick with Yamaha parts.

Nothing wrong with using OEM parts to cut costs on parts like filters, stats, washers, etc. But when it comes to main components, like a water pump, fuel pump, etc., it's highly recommended to use yamaha parts. You'll save more money and time over the course of your ownership of the engine.

Just some friendly advice. Welcome aboard and let us know the results.

[ryanmaker]

Wise words Jason....I will not be using after market parts after this experience.

As I started to put it all back together, I noticed that the new impeller has a metal sleeve (the one I took off did not), I could not get the impeller to slide down the shaft without tapping in down. Of course I missed the woodruff key by a hair, and now the impeller is stuck on the shaft and will not move.

I will be buying the YAM OEM impeller, probably cutting this Sierra one off.

Never fails...even the simplest of jobs can become a major pain, when using non OEM stuff...

I'm looking at the shaft oil seal and its looks slightly disfigured, almost like some corrosion or build up around seal edge if pushing seal away. It appears to still be "sealed" but I'm now thinking about just taking lower unit to someone and having it overhauled/all seals replaced etc...


Ryan

[Jason2tpa]

Not sure if the impeller of your model/year should or should not have a metal sleeve, or whether or not it matters. But I am sure the impeller should not need to be tapped down the shaft.

A coating of marine grease needs to applied to shaft before slipping the impeller down, which its hole should also be greased. Then with a very little downward hand pressure, the impeller glides down the shaft. Bring it down to just above the woodruff key, line it up, push down to mount. This entire process should be very easy.

The only way I can imagine you moving the impeller below the key without it being lined up is if you forced it....by tool tapping it down.

If the key was in the impeller groove the impeller can be moved back up the shaft. So being that it will not, sounds like it is misaligned.

I'm looking at the shaft oil seal and its looks slightly disfigured, almost like some corrosion or build up around seal edge if pushing seal away. It appears to still be "sealed" but I'm now thinking about just taking lower unit to someone and having it overhauled/all seals replaced etc...

You'll have to post a photo of the this slightly disfigured seal to receive an accurate diagnosis. But either way, bringing the lower unit to an experienced tech is a good idea.