Stuart P55MR

Talk about interesting old outboards which aren't Seagulls here

Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo

User avatar
Oyster 49
Posts: 3311
Joined: Tue Oct 26, 2010 6:55 pm
Location: Derbyshire, UK

Re: Stuart P55MR

Post by Oyster 49 »

Great attention to detail here, very interesting read 8)
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Thank you Oyster.

I don't have the tools or the experience Nudge. The new seals may be less interesting, but I expect they will provide better overall performance.

Anyway, back now to where I was a week or so ago, however this time with both shaft seals and gearbox drive seal replaced, a few other components fitted and some issues sorted along the way.

For the benefit of those contemplating replacement of seals in Sturt Turner P5, P55, P6, P66 Marine Engines (and probably other models as well), the following pics and notes will be of assistance. Needless to say, reverse order applies for removal.

Replacement seal (type SC 200 112 37 TTEO 23 4) fitted to rear crank case housing.

Image

Magneto/Waterpump drive sprocket installed on shaft. Note locating pin.

Image

Spacer installed on to shaft.

Image

Fit chain to sprocket. Secure with wire or similar at upper end, until ready to install the Magneto drive assembly.

Image

Fit external bearing retainer. Comprises a recessed flat section at rear side to facilitate correct alignment. Secure into position with washers & screws (2). Note bearing faces out to clutch cone. Take care when removing/fitting this bearing. It will fall apart but is easily reassembled.

Image

Fit shaft keys (2), clutch cone and secure with nut. An 11/16BSF or 5/8BSW tube spanner is required.

Image

I forgot to photograph the replacement of forward shaft seal, however this is a much more straight forward process. Remove forward crank case assembly. remove bearing from shaft. Remove old seal and collet. Clean and lubricate all. Refit collet. Fit seal. Fit bearing. Refit forward crank case section.

All above is well worth doing in my humble opinion. Only real problem is sourcing a suitable tube spanner ie as without removing the clutch cone access, the crank shaft cannot be removed from the rear crank case section. Small investment for big gains. Expect to pay around $10 Australian for the crank shaft seals (2) and the gearbox seal (type HSU JAU HJ 801098 TC 1.437 2.250 0.375, not shown here), grease nipples and a couple of circlips.

Here she is again, this time with control column and magneto drive in place.

Image

All bright hardware will be painted over per original in due course.

Regards,
www.vintageoutboardsaustralia.blogspot.com
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Gearbox has been coupled to the engine. It engages forward and reverse and transitions through neutral along the way. Reverse and back to neutral requires additional force albeit that the eccentric at the base of the control column has been adjusted for optimum performance in accordance with the manual. I suspect cause to be lack of oil in the gearbox, however until the sump plugs are polished and fitted and the gearbox has been correctly filled with SAE30, I won’t know for sure. Excuse the image quality.

Image

Next step will be sourcing alternative head gasket material (I don’t want to use copper again), making the head gasket and fitting the cylinders/expansion chamber and head.

I’m in absolutely no hurry to complete, as there are many other projects to keep me busy in the meantime.

Regards,
Spiro
www.vintageoutboardsaustralia.blogspot.com
User avatar
Oyster 49
Posts: 3311
Joined: Tue Oct 26, 2010 6:55 pm
Location: Derbyshire, UK

Re: Stuart P55MR

Post by Oyster 49 »

Things like this can only inspire others and help to keep the scene going. Great work in sharing 8) You are not really going to paint over that nice brass and copper are you?
User avatar
Charles uk
Posts: 4951
Joined: Wed Feb 27, 2008 4:38 pm
Location: Maidenhead Berks UK

Re: Stuart P55MR

Post by Charles uk »

How does the timing chain get lubed, now you've replaced the "seal" that permitted oil through, but with very little crankcase compression loss, with an lube tight nitrile oil seal?

Or is there an external oil nipple fitted?
Make it idiot proof and someone will make a better idiot.
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Oyster 49 wrote:Things like this can only inspire others and help to keep the scene going. Great work in sharing 8) You are not really going to paint over that nice brass and copper are you?
Hello Oyster,

Thanks again for the kind words.

I probably should have been a little clearer in my above post. Only the steel fasteners will be painted over. Brass and copper will be polished ie with the exception of 3 only brass components which I felt looked a little out of place unpainted.

Regards,
S
www.vintageoutboardsaustralia.blogspot.com
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Charles uk wrote:How does the timing chain get lubed, now you've replaced the "seal" that permitted oil through, but with very little crankcase compression loss, with an lube tight nitrile oil seal?

Or is there an external oil nipple fitted?
G’day Charles,

The timing chain is housed within what is essentially an extension of the gearbox housing, which is of course is semi filled with gear oil.

It’s too late now to get a photo of the sprocket, chain and dip stick together, but I will attempt to take some measurements just to see how all line up. This is I'm sure lubrication is caused by the splashing of oil from other rotating parts when the engine is cranked by hand and in operation.

The change in seal type is discussed in the Stuart Turner section of Oldmarineengine.com. There are also several ‘in service’ and ‘running display’ ST’s in Australia with the same seal mods. Had that information not been available, I would have been reluctant to change from the original seals.

Thanks & regards,
S
www.vintageoutboardsaustralia.blogspot.com
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Another small step forward with the Stuart over the weekend.

The original plan was not to proceed to this stage before all the brass dome nuts etc had been properly polished and clear coated, but I’ve been struggling with motivation to do that.

So the plan now is to pick up some more BSF nuts and washer during the week and use those to temporarily replace the brass dome nuts until the polishing of those has been completed.

Image

Image

Image

Image

Image

Image

PS: Gasket material chosen is 1mm thick Klingersil C4430 rated at approx. 430C and bedded down Locktite 515. Not the easiest of materials to work with and clearly over the top for this application, but I’m happy with it.

Regards,
S 
www.vintageoutboardsaustralia.blogspot.com
User avatar
Hugz
Posts: 3282
Joined: Wed Mar 14, 2007 4:41 am
Location: Sydney

Re: Stuart P55MR

Post by Hugz »

May 1950 Seacraft Magazine
Stuart Engine. .JPG
Dec 1949
Stuart.JPG
User avatar
AusAnzani
Posts: 1002
Joined: Wed May 21, 2014 10:47 am
Location: Australia
Contact:

Re: Stuart P55MR

Post by AusAnzani »

Thanks for that Hugz,

You are a true gentleman!

I'll get around to finishing the Stuart one day. Just needs the Water Pump & Carby polished and refitted.

Regards,
www.vintageoutboardsaustralia.blogspot.com
Post Reply