Yamabond sealed motorcycle cases
- Thread starter mofosheee
- Start date
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Your not going to affect it with acetone or normal heating. That is why it is used on engine cases.
If you look around, you'll find some bosses to pry between to get the separation started. Patience !
If you look around, you'll find some bosses to pry between to get the separation started. Patience !
jkimberln
Well-Known Member
Engine cases are easily split using a single edge razor blade and a small hammer. At least that is the way I do it.
If you're going to start hitting razor blades with a hammer, be prepared for the blade to shatter.
I did exactly this in my much younger days.
Removing shards of blade from my thumb required surgery.
Heavy gloves and eye protection are a minimum!
I did exactly this in my much younger days.
Removing shards of blade from my thumb required surgery.
Heavy gloves and eye protection are a minimum!
When I was racing amateur off road in the Mojave Desert with a Yamaha 175 MX in the early 1970's, I seem to remember a tool you would use like a gear puller, only in reverse. After taking out the clutch assembly, this tool would screw into the case half over the crankshaft and you would screw down on the crankshaft end and it could pop the case half apart.
Found this video:
And here's one on eBay:
https://www.ebay.com/itm/184726184265?hash=item2b0289e149:g:CGkAAOSwRRpgXD6g
And here's one on eBay:
https://www.ebay.com/itm/184726184265?hash=item2b0289e149:g:CGkAAOSwRRpgXD6g
Having worked for a major car maker (Japanese head office based) I learned for "localising" materials and engine components to European suppliers that the "glue" that makes their engines oil tight is simply a formulation of silicon sealer, but with a very high solid (filler dust) content. This makes it an incredibly solid "silicon rubber bonded" filler material, that actually sticks like the proverbial.. or "burnt egg to an aluminium frying pan"! Flanges were designed differently to the European traditional simpler designs (developed for paper gaskets) that were almost guaranteed to leak with age...
But the traditional joints could easily be separated, as was necessary for a design needing regular and frequent maintenance, whereas the majority of "Japanese" designed joints with this sealer never come apart until the vehicle is scrapped. And never leak. (Happy customers!).
So there are aftermarket tools - developed for the small minority that actually wear out engines and need to dismantle them. I don't know where you can get the replacement for the "Yamabond", though.
K2
But the traditional joints could easily be separated, as was necessary for a design needing regular and frequent maintenance, whereas the majority of "Japanese" designed joints with this sealer never come apart until the vehicle is scrapped. And never leak. (Happy customers!).
So there are aftermarket tools - developed for the small minority that actually wear out engines and need to dismantle them. I don't know where you can get the replacement for the "Yamabond", though.
K2
Presumably we're talking about Yamaha cases and I've used three to drive (one Suzuki dual-range ag bike 'box, too) a shaper and two lathes and of course, I've had to split the cases to delve into the innards. Splitting was done by placing a stub in the threaded 'half', then cutting a thread in the non-threaded bit (there's usually enough 'meat') and the rest is hoopla. For re-joining, I used a gasket cut from a fibrous material which printers call 'presspak' and the usual goop. Mostly it's case of buying a whole engine, most of which was scrap, but they are cheap as chips and the gearboxes are excellent. I don't usually use the clutches.
