Coolant leak

[Massif]

Hi,
I have a little coolant leak at the rear of the right hand cylinders about 1.5 cm below the cylinder head gasket, it appears as a little bubble through the metal about a pin prick size and develops into a drip. I'm considering using a radiator anti-leak product (like Barsleaks) and see how this goes. Otherwise I'll have to remove the motor to gain access to drill and tap a small thread and insert a grub screw.
Welcome to any suggestions.
Cheers, Simon

[Brock]

Dont use Bars leak, some of the galleries in the bike engines can be blocked, and then you have real trouble.

Have a good look around, its not unknown for these engines to have a leak higher up or in the valley, that looks like it originates in easy to see places. Give the area a very good scrub down ( steel wool or scotchbrite ).

If you do drill and tap, try to find a brass plug, as a steel one will corrode very rapidly doing huge damage. Drill slowly, and use grease on drill and tap to catch swarf. (suggested, as I dont know haow converant you are with such stuff)

[Massif]

Thanks Brock,
Will give the Bars Leak a miss. The leak definitely is coming through the metal so it look like dropping the engine out etc. is the plan. I'm good with the drilling and tapping etc. This will give me an opportunity to give the rest of the hard to get to spots a thorough clean.
Cheers, Simon

[saaz]

What vintage is the ST1100? There were some rare cases of cracks in the engine casing around the casting marks, but over the years I have only seen reports of a couple. Grinding it out a bit and using some sort of metal repair product should do the job (eg JBweld)  Good luck and let us know how it goes.

[Biggles]

What vintage is the ST1100? There were some rare cases of cracks in the engine casing around the casting marks, but over the years I have only seen reports of a couple. Grinding it out a bit and using some sort of metal repair product should do the job (eg JBweld)  Good luck and let us know how it goes.

That's not as silly as it may sound to some.  It used to be Araldite that was recommended, but JB Weld is superior.  You'll need to drain the coolant to get a dry adhesion, of course.

[Massif]

It's a 2000 model ex WA Police, been a great bike and have had lots of reliable riding. Thanks to all for the replies, I think I'll try a bonding agent either as discussed i.e. Araldite, JB Weld or Devcon. The latter would be my choice. Feel free to comment please.
Regards, Simon

[Brock]

Devcon aluminium putty is excellent stuff.. Definitely use a dremel or a small die grinder to excavate the site first. Then you can fill and level the area, back to good as new or better

[Massif]

Purchased Devcon today the repair will have to wait until the weekend, thanks Brock and others for the useful comments. Will report back after the fix.
Cheers, Simon

[Brock]

Dont forget to take pics, they can help others  to do the job

[Massif]

Update on repair to leak. I used the DEVCON aluminium putty after thoroughly cleaning and 'excavating' the area, after 5 days of letting the DEVCON cure I refilled the system with coolant and started the engine. Almost immediately coolant appeared from the 'repaired' area. I have removed the DEVCON to investigate, the putty chipped off without to much trouble. I discovered that the 'pin hole' was probably fixed but discovered a hairline crack about 25mm long! Plan B is to remove the engine and have the crack welded, fortunately locally we have a guy who is an expert with a TIG. Will keep you all posted with the work.
Cheers, Massif

[Massif]

I finally found the time to have my local welding guy attempt to weld and repair the crack(s), unfortunately the crack was bigger than we thought starting below and rear of the cylinder and travelling around to the right hand side travelling about 125 mm in length. We built up the weld but it still leaked and even had the head gasket leak due to the heat. So now it's either procure another engine or find a top half of crank case and use that. I have added to my watch list on eBay a couple of crank case top halves (both in the USA).
It's not the end of the world as my Norton and Triumph bikes are running wonderfully, I know lots of people dump on British bikes but they always go when I need to ride!!
Anyone out there got an engine or crank case top half in good condition for sale? I make the best Shiraz in Western Victoria so I'm more than happy to barter I know there has to be someone with a craving for some good reds!
Cheers, Massif