Yamaha 8hp 2 stroke outboard with holes in water jacket

[Howard1952]

Part of the waterjacket is paper thin. The engine ran very well prior to perforating the jacket but was totally full of crud so the water cannot have been doing much cooling.

I'm thinking about possibly eliminating completely the short holed track or setting a track in an epoxy repair with a length of 2.5mm electric cable as a water track. Alternatively, I could use a braze in aluminium rod. Any thoughts on this?

Does anybody know the correct torque setting for refitting the cylinder head bolts?

 

[Plum]

Part of the waterjacket is paper thin. The engine ran very well prior to perforating the jacket but was totally full of crud so the water cannot have been doing much cooling.

I'm thinking about possibly eliminating completely the short holed track or setting a track in an epoxy repair with a length of 2.5mm electric cable as a water track. Alternatively, I could use a braze in aluminium rod. Any thoughts on this?

Does anybody know the correct torque setting for refitting the cylinder head bolts?

I have repaired a hole in the waterjacket of a Mariner 2stroke where some water was trapped, engine laying down and the water froze. So far the repair has been successful. Bonded a small sheet of 2mm thick brass over the hole using JBWeld high temperature resin JB Weld Original Cold Weld Formula: Amazon.co.uk: Kitchen & Home

www.solocoastalsailing.co.uk

 

[VicS]

Part of the waterjacket is paper thin. The engine ran very well prior to perforating the jacket but was totally full of crud so the water cannot have been doing much cooling.

I'm thinking about possibly eliminating completely the short holed track or setting a track in an epoxy repair with a length of 2.5mm electric cable as a water track. Alternatively, I could use a braze in aluminium rod. Any thoughts on this?

Does anybody know the correct torque setting for refitting the cylinder head bolts?

Yes ... Its in the work shop manual

Page 6-130 http://www.boatinfo.no/lib/yamaha/manuals/1984-1996yamaha.html#/0
(6 lbs ft , 11 Nm )

 

[Birdseye]

Part of the waterjacket is paper thin. The engine ran very well prior to perforating the jacket but was totally full of crud so the water cannot have been doing much cooling.

I'm thinking about possibly eliminating completely the short holed track or setting a track in an epoxy repair with a length of 2.5mm electric cable as a water track. Alternatively, I could use a braze in aluminium rod. Any thoughts on this?

Does anybody know the correct torque setting for refitting the cylinder head bolts?

Scrap bin! 8hp implies that it is the main power source for a boat and not just a dinghy outboard. If so a bodge of the sort you describe is risky.

 

[Graham376]

Scrap bin! 8hp implies that it is the main power source for a boat and not just a dinghy outboard. If so a bodge of the sort you describe is risky.

Plenty of dinghies around with even larger engines. Any "bodge" is a well worth exercise on a popular engine and, if necessary, I would rather buy a new block for the 2 stroke than a new 4 stroke engine.

 

[Howard1952]

Scrap bin! 8hp implies that it is the main power source for a boat and not just a dinghy outboard. If so a bodge of the sort you describe is risky.

Engine is mainly for tender to cruiser. Looking at the design I suspect the bodge is no worse than the original casting. If a new casting could be obtained I would be happy to buy one.

 

[Howard1952]

Yes ... Its in the work shop manual

Page 6-130 http://www.boatinfo.no/lib/yamaha/manuals/1984-1996yamaha.html#/0
(6 lbs ft , 11 Nm )

Thank you very much for this. I don't seem to have the correct software to read the manual but probably don't need to now I have the torque settings.