1986 150 yamaha water in my lower unit

sven

sven

New member
I'm trying to decide if I should replace my lower unit as I have the kaluaha milky oil situation. Motor ran fine all last season and I was thinking of just monitoring the situation. My mechanic says its not really worth re-sealing a LU this old when you can get a new after mkt one for $800 or so (he will install for $200 labor). Any guidence is appreciated. The motor runs good and I think the power-head could hopefully go a few more seasons. Should I drop the grand and get a new LU, try and re-seal the old one myself (or get someone to do it) or just run it and keep and eye on the oil.....I dont have a trailer so if I dont do it and it fails it'll cost my $$ to pull the boat and re-cider block to get it done.
 
Whats your location? Can't you rent Boat trailer for the day or week? Here in Orlando this is an option.
As for the cost of a LU for an 86 motor all I can say is WOW! One thousand dollars ?
I can recommend you shop ebay or craigs for a LU and replace it yourself and save a few bucks. I am guessing you can do since you mentioned you can do the re-seal, swapping the LU is much easier.
Here is an LU with a 90 day warrenty for around 700
http://cgi.ebay.com/ebaymotors/YAMA...7935157QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear
 
Thanks. I'm getting lazy these days. Too much work during the week at my job to be fussing with the motor on my weekends I guess. I actually used to like doing work on the engine, not anymore. For 200 bucks i get it done with the water pump as well. I was just wondering if some water intrusion in the LU is acceptable. The other thing I was concerned about is re-sealing a LU thats 24 years old. Dont know what the cost is to re-seal versus replace. The quote i got for $800 for the LU, plus 200 labor didnt seem that bad. Resealing's gotta be a lot more in labor. One friend told me 500-600. So it seems logical to get a new one.
 
$200 to replace a lower unit is downright robbery, plain and simple. Unless the lower is frozen into the midsection and needs to be cut out, then that is a 1 hour job tops. The $800 for a lower unit isn't that bad actually since it is for a YAMAHA, but this is an 86 engine. Has the shift shaft been replaced on it yet? If not then I wouldn't dump anymore money into it as that right there can be a very costly repair. For an old engine like that I would seriously reccomend finding another outboard if your going to put $1K into what you have now. Chances are you can find a complete outboard with a blown powerhead for less than the $1K and have all kinds of spare parts. I personally would re-seal what you have yourself. If it is seized together though then it will get expensive once you need the torch and pullers to release the bullet in it. Good used lowers can normally be had for $500 or less for low time units even for a YAMAHA.
 
Thanks. I'm probably gonna get the LU pressure tested to see where its leaking. If it is I may just re-seal it. I noticed the washers on the fill and vent screws look pretty shot so maybe thats the problem. When I drop the LU i will inspect the shirt rod. I'm hoping the previous owner may have replaced the shaft. If it looks shot then I may just run it till it fails on me (i fish only in Sandy hook bay in nice weather and have towboat ins) or dump it and get myself a new motor this spring before i put it in. Cash is the main factor in making that decision.... seems to always be unfortunatly.
 
On a previous motor of mine the lower unit had been serviced just before I bought the boat. Being foolish I trusted the mechanics work and just checked and found the oil clean and ran the boat half the season before I checked the oil and found it was all milky looking.
I changed the oil, and replaced the washers which should be done each time and were not, ran the motor the rest of the year and each year after and no more milk.
It was the washers, also if you have a mild leaking seal somewhere there are some fluids to put in your oil which will seal the leak and they do work. I can't remember the name of it now but according to a marine mechanic it does work well unless the a=seals are just boken or rotted bad, good luck
 
Taking off the lower unit doesn't give you a better view of the shift shaft. You can only get a peek at a tiny section of it rigt below the where the lower mount bolts are on the midsection.

Ebay would be a crap shoot and you could get stuck with another one that leaks. I'd change the oil and run it for a trip or two and then see how much water you get. Maybe you can live with it with more frequent oil changes?

If you were willing to DIY I would try just doing the seal under the water pumo first and se if that helps.

For $800 you wouldn't be getting an OEM Yamaha but more likely a new clone by Sterndrive Eng.

http://www.sterndrive.cc/Merchant2/merchant.mvc?Screen=PROD&Product_Code=90-416&Category_Code=SE416

They have made replacement Merc Alphas for a while and now have outboard lower units.
 
sven said:
Is there any way to inspect the shift shaft without pulling apart the whole motor?
Click to expand...

Look at the forward edge of the midsection just below where the lower pivot connects.

inspectshaft.jpg


You can just catch a glimpse of the shaft. It is as thin as a pencil to start and you won't really be able to tell what sort of shape it is in from wat you can see but hopefully what you will see is tat it has been replaced at some point and is now nice shiny stainless steel. You could test the strength of the shaft by removing te lower unit and then holding the top of the shaft (right under te block) while at the same time having someone insert a suitable tool into the bottom of the shaft in order to apply torque to see if it is solid. Be aware that this may ultimately turn into a destructive test if the shaft is on its last legs. Here is a link to my old thread about my shaft replacement that shows some photos of the process and a picture of the shaft itself on the last page:

LINK
 
Here is what the shaft looks like:

x1.jpg



It rots mostly at the very bottom which is not visible with the motor together:

x2.jpg


Im not sure but the coupler at the bottom may be SS even on the steel shafts.
 
I took the LU off today and got a glimpse of the shaft and it was unfortunatly corroded. It feels like it still has some meat on it (at least thats what I'm hoping). I'd say if the shaft is around 7 millimeters diameter, the thin section due to corrosion (that I can see) is maybe 5 mm. So I'm going to pressure test it, re-seal (maybe I get lucky and its simply the crappy looking washers on the vent and drain plugs....make it nice and easy), throw it back together and run it. No funds at the moment to look for a new (used) motor. I'm just hoping it will last one more season and I can swap it out in the fall.

Anything I can do to stretch the life of the corroeded shaft for a couple of months? I guess I could throw some grease to help slow the exisiting corrosion for a while. Take it easy on shifting is another I guess. Anything else? Anybody have any ideas?

Thanks for everyones advice!
 
Really not much can be done. When mine started to go it was not shifting right, I had to adjust the cable to make up for the twist, after 2 adjustments the shaft broke.
 
Nope, I don't think that there is anything that you can do to protect the shaft from further corrosion. Too much of it is just too inaccessible to do anthing to it.

I have done a jury rig repair to a broken shaft that is still going strong after two years, but it can only be done after the shaft has broken.
 
Hey monkey I would love to here about the jury rig repair can you tell more about what you did ....I did some searching and found a few guys that retrofit the shaft with some sort of coupling
 
I'm just going to throw new washers on the vent screws, do the water pump and leave it at that....if it the shaft or LU goes, it goes and I look for a new used motor somewhere, or a new used boat. My 10 year old wont let me go a season without a boat, plus I'm paid up on my slip for the season. I'll post how things go.

Thanks
 
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