Help With Engine Corrosion Please!

Could you post some pictures to show the problems ?

 

Normalish for these areas to corrode, I think it's due to not cleaning these areas, and corrosion getting a start under the coatings, If you post photos they may rule out leaks completely. The studs will corrode because of the hot cold cycle they are involved in.
I can't recommend fixing stuff that isn't broken.
Although I would want to replace them too. They won't improve.
World of Triumph are a resorse, although expensive.
The Alloy corrosion on the block is probably best cleaned back to metal and painted.

 

With regard to stuck nuts , ooer! Check here it really does work

 

ACF 50 will help, it works.
Good luck

 

Just remember this is cosmetic........on a 7 yr old bike.

The powdery aluminium oxide corrosion is itself a very effective barrier to further corrosion. The problem is that it will track under the powder coat and lift it.

It is an awkward spot to access but your choice is really to monitor its spread until you cannot live with it (or choose to sell the bike) and/or cleaning back to bare metal and painting with an aluminium primer and high temp gloss black to match. It is a small wire brush/Dremel/skinned knuckles sort of job......

 

Hasn’t @BB3Lions recently posted very similar corrosion in that same area?

 

Doesn't look too bad . Only takes riding in winter to set off rusty nuts

 

Any resident metallurgists?

I suspect the issue is simple galvanic corrosion. Basically you need steel studs to hold the exhaust on an aluminium casting. The two metals conduct electricity differently and that difference in ‘potential’ means one corrodes ‘preferentially’ - like a one way chemical flow. Throw in an electrolyte (a conductive solution) like salty water and the process accelerates.

If the surfaces are clean and then coated (ACF50 etc.,) you inhibit the entire corrosion process.

 

You could just spray the parts and carry on riding ....

 

I would strip down the area for ease of access and rub down anything suspect having probed with a flat blade screwdriver. That will reveal corrosion blisters rather than just rough finish. Mask off and use a brush. Less messy and ‘good enough‘ for under there. The big thing is getting back to bare metal, cleaning off with acetone (her nail varnish remover!) and using an aluminium primer. High Temp gloss last....

 

Or similar
https://www.amazon.co.uk/500ml-Silver-Aluminium-Resistant-Temperature/dp/B00AC2206I
Or
https://www.amazon.co.uk/XtremeAuto...coding=UTF8&psc=1&refRID=MC8DM83SZ57A3X921FZR
See double deal incl black gloss scroll down

Otherwise this stuff you can spray and brush on
https://www.halfords.com/motoring/p...oniz-silver-very-high-temperature-paint-500ml

Your surface temp should not greatly exceed the cooling water under pressure just over 100C but adjacent the exhaust ports it might be a bit higher.

 

On a last note, these days aluminium used is just recycled shite that why it’s always painted. I’ve an old eastern block Mz in bare aluminium been stud in a wet garage for 20yrs (before me) with virtually NO ENGINE CORROSION!
That’s because recycling wasn’t as popular and only quality virgin aluminium was used.

 

Except your virgins have been corrupted too. Almost all of the aluminium used is/are alloys containing silicon, copper, magnesium etc., to give it the desired properties. Recycling does not mean melting and pouring any old iron without checking the recipe. Your MZ probably had a good chunk of zinc in it. My old Ossa was similar.......and quite brittle as I found out!

 

My two year old Tiger has this issue too. Think it is a Triumph thing.

 

Mazda too. You should look at the underside of a 6 yr old MX5 but the effect is almost entirely cosmetic on the hubs and spars.

 

Worked on the underside of those heaps plenty of times! They look like they’ve turned to stone!

 

Square Deal has stainless steel studs and they are very well made, I also found all metal stainless locking type (torque prevailing) nuts one Ali Express although you will have to wait a few weeks for them to come from China.

Jim.