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Merc 9.8hp lower seal

J

JoshNZ

Member
Hi fellers,

I've come across a 1977 (I think) Merc 110 9.8hp that hasn't run in a decade or so, though was when it was put away.

I figured it is probably a good idea to do the impeller. Was wondering are they available anywhere for models this old? And what about lower unit seals? Is it possible to make a seal out of generic gasket sheet or product for the lower unit?

Other than that I think cleaning up the carb will have it firing right away.

Thanks in advance!
Josh
 
That impeller will be in stock at most Mercury dealers .--A very common item.--------------Oil seals are not made from gasket material !!
 
racerone said:
That impeller will be in stock at most Mercury dealers .--A very common item.--------------Oil seals are not made from gasket material !!
Click to expand...

If I remove the lower unit to get at the water pump what kind of seal will there be between the two? And am I likely to damage it? It's been a long time since I worked on outboards I thought that was just a water seal and the water pump/gear case were sealed separately, guess I'm wrong?
 
I've done several dozen of these (and for one customer!) The top seal (which is easy to replace) often needs replacement, where the lower usually does not.

The Lower unit is very difficult to get back on, so if you have a problem post me.

Question: Have you seen what's inside the lower unit? If water does NOT come out, fill with oil and go boating. If it does...post me.

Jeff
 
There are 2 impeller listed for these motors.--------------------Depends on the driveshaft diameter.-----------Get the correct one.
 
fastjeff said:
I've done several dozen of these (and for one customer!) The top seal (which is easy to replace) often needs replacement, where the lower usually does not.

The Lower unit is very difficult to get back on, so if you have a problem post me.

Question: Have you seen what's inside the lower unit? If water does NOT come out, fill with oil and go boating. If it does...post me.

Jeff
Click to expand...

You mean if I open the gear oil filler cap and there's no water in there?

To be honest I have done nothing to it yet, and I didn't plan on disassembling the lower unit, just impeller replacement. I got it out of the shed and removed 2 mice nests from next to the block. Drenched it in degreaser then threw a bucket of water over it and called it a day. I know the carb will need cleaning as the owner mentioned it was playing up before it went away.

Those water pump kits are more than I really want to spend on it. I will see what state it is in first.

Thanks for the wealth of helpful comments! Will let you know how I get on.
 
I got the carb cleaned out today. Stripped one of the pilot jets trying to remove it and ended up cleaning it in there, I'll worry about that another day. Can you drill them and use extractors on them? Hopefully I never need to remove it.

It fired up after that and the water flow was a little slow so I pulled the foot off. The front nut was only finger tight and I found out why when I went to do it back up - the thread in the foot end is stripped. I guess it can stay in there permanently if there is a way? Or what else can you do about it? I've heard of helicoil inserts but never seen them available in any store, do they work?

And a question for later, when it comes to tuning the engine. I can only see one adjustment screw being the idle mixture. Is top end purely controlled by jetting? All I do is set for a nice idle and that's it?
 
JoshNZ said:
I got the carb cleaned out today. Stripped one of the pilot jets trying to remove it and ended up cleaning it in there, I'll worry about that another day. Can you drill them and use extractors on them? Hopefully I never need to remove it.

It fired up after that and the water flow was a little slow so I pulled the foot off. The front nut was only finger tight and I found out why when I went to do it back up - the thread in the foot end is stripped. I guess it can stay in there permanently if there is a way? Or what else can you do about it? I've heard of helicoil inserts but never seen them available in any store, do they work?

And a question for later, when it comes to tuning the engine. I can only see one adjustment screw being the idle mixture. Is top end purely controlled by jetting? All I do is set for a nice idle and that's it?
Click to expand...

Are you saying the rear stud is stripped out of the lower unit? If that's the case I can tell you what to look for and how to repair it. You don't need to helicoil. Read my post titled "Merc 9.8 crappie engineering".
 
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