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In the process of rebuilding my Kawasaki KH400 and the crank bearings need to be loctited in the crankcases - it is standard practice to apply loctite to the bearing outers.

Before applying some new loctite I need to remove the residue left on the bearings, so my question is, does anyone know of any solvent that will remove cured loctite?, so far tried Acetone, Meths, and Petrol, but neither seem to work.

Anyone any suggestions ?

I'm not aure if all loctite products are the same, but with loctite 542 a hairdryer will soften it for easy scraping. I then used a universal cleaner solvent which I have for surface prep to remove the residue. This was a Motul sample which I bought at an autojumble. All the writing is Japanese so I don't know the specific constituents. I will see if there's a part number when I'm back in the shed. Might be able to glean details from that.

Really depends on exactly what was previously used to retain the bearings.

Loctite are pretty good at publishing technical data sheets for their products so have a look on the Henkel website for the TDS relating to the product you used.

Assuming it was 641 then the TDS says soak in loctite solvent and mechanical abrasion with a wire brush. Doesn’t specify the solvent though! So still not mega helpful, but I’m sure Henkel could advise.

641 TDS is here:
https://datasheets.tdx.henkel.com/LOCTITE-641-en_GL.pdf

Really depends on exactly what was previously used to retain the bearings.

Loctite are pretty good at publishing technical data sheets for their products so have a look on the Henkel website for the TDS relating to the product you used.

Assuming it was 641 then the TDS says soak in loctite solvent and mechanical abrasion with a wire brush. Doesn’t specify the solvent though! So still not mega helpful, but I’m sure Henkel could advise.

641 TDS is here:
https://datasheets.tdx.henkel.com/LOCTITE-641-en_GL.pdf

Thanks for your thoughts - the recommended Loctote grade is 620, assuming that is what was used the last time it was rebuilt, it looks like heat and "mechanical aids" are the way to remove it according to the TDS.

Cant really apply heat due to the crankcase oil seals fitted either side of the bearings, so guess I'll be manually scraping it off with an old hacksaw blade.

Andy_C wrote: ↑23 Nov 2024 09:01 Cant really apply heat due to the crankcase oil seals fitted either side of the bearings, so guess I'll be manually scraping it off with an old hacksaw blade.

One way to spend a stormy Saturday.

Very true, although it it not actually as bad as the forecast.

It is a bit gusty, a few light showers of rain, but surprisingly warm for the time of year - very tempting to bung the waterproofs on and take the trusty old Enfield Himalayan out for a spin.

Andy_C wrote: ↑23 Nov 2024 13:49 - very tempting to bung the waterproofs on and take the trusty old Enfield Himalayan out for a spin.

Old? LOL. From a man with a KH and a 3½!!!!

Funny how I call it the "old" Enfield, probably because it is the one I have had the longest.

Managed to sort the loctite problem out, using a ground down hacksaw blade I gently scraped it off the bearings, then rubbed some acetone nail varnish remover on it, scraped again, and repeated. Ended up with nice clean surfaces.

Cases are now "buttoned back up" and engine back in the frame