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Vintage Australian Outboard Runabouts => Information Wanted => Topic started by: 007leachy on May 03, 2022, 04:17:00 PM

Title: New to Classic Boats
Post by: 007leachy on May 03, 2022, 04:17:00 PM
Hi All,

Im new to the classic boat scene. I bought a Glastron 1970 V-156, fitted with 75hp Merc 4 cyl. I believe its a 1986 model motor bot not sure. I want to get it all sorted out before it hits the water. Starts up fine and pumps water ok but want to change the impeller as its had very little use over the past 10 years. Does anyone know what the kit impeller part number would be.

Thanks in advance.


Title: Re: New to Classic Boats
Post by: True blue on May 04, 2022, 11:34:54 PM
Welcome Jason to The Board website.

Hopefully one of the members will have an answer for you.


Title: Re: New to Classic Boats
Post by: MERCMAN on May 12, 2022, 12:59:23 PM
G'day Jason,
(thanks for the intro' Julian)

Welcome from me too!
Yes, your gorgeous motor is 100% a 1986 model, provided the decals haven't been changed. Those gutsy 4cyl motors have a good history and a great blood line. They have so many parts interchangeable with their Inline 6 cylinder big brothers, it's not funny.

The Impeller (to suit) has had quite a few Part Numbers over many years. The dimensions haven't changed, the material itself has of course evolved.
47-89984T4 should suffice.

Any Merc dealer worth their salt will provide you with the correct impeller. I'd remove the impeller housing and have a close look, before investing in a Water Pump Kit. In saying that, no matter what your Impeller looks like, it's imperative you change it!

There are lots of You Tube vids showing how to change the Impeller. If you own an imperial socket set and some open-ended or even ring spanners, you'll be OK. There are rather two tricky areas, but I can always talk you through those, over the phone.

Also, I can guide you through a full service, if you wish.



Title: Re: New to Classic Boats
Post by: MERCMAN on May 12, 2022, 02:19:16 PM
Here is a vid' for you to watch.

This young guy managed to complete the job the hard way. By watching, at least you can see what to expect to find when the gearcase has been separated from the mid section.

1. The Water Tube usually stays put (connected to the Block)
2. Eventually, he worked out that he should have reinstalled the Water Tube before trying to refit the gearcase.
3. That was the wrong way to install any outboard impeller.

a. Do NOT use any type of oil on any outboard impeller. Use plumbers "O" ring and washer silicone/lube.
b. Apply a dab grease to drive shaft recess for Impeller Key.
c. Install Key.
d. Slide Impeller down drive shaft and over Key.
e. Slide Pump Housing down drive shaft and let it sit gently on top of the Impeller.
f. Whilst rotating drive shaft slowly with one hand, press down on top of Pump Housing with the other hand until the Housing seats. Fit and tighten all nuts and  screw.
g. Lubricate the rubber Slinger and slide it down all the way down the drive shaft, until it sits snugly on top of the Pump Housing.
h. Apply grease to drive shaft spline and shift shaft spline, as well as all the studs.
When refitting a gearcase, always remove all Spark Plugs so it's easier to slightly rotate the flywheel by hand thus enabling the crankshaft splines and the drive shaft splines to line up (mesh).

I always ensure the control box is in Neutral before removing the gearcase. When is Neutral there is virtually no easy movement possible, of the gearcase end of the shift shaft assembly. Thus making the entire refitting process of the gearcase, far less troublesome.