hairline crack on the engine mount

Wheels, shocks, forks, frame
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dirk
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hairline crack on the engine mount

Post by dirk »

Hi folks

I find (again) a hairline crack on the engine mount. :(
it has been welded.
what is the cause?
how did you do that?

Image

regards
Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
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JanBros
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Re: hairline crack on the engine mount

Post by JanBros »

tolerarances for the spacer are too big. it will need welding again, and then you'll need to shim the spacer (or make a new one) so that it just fits in between.

yours has too much play, so when bolting it together, it bends and has to endure too much stress.
My ultimate goal is to die young as late as possible !
dirk
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Re: hairline crack on the engine mount

Post by dirk »

Hi Jan

thanks for the reply.
i can remember that the engine was mounted without play.
the spacer was specifically designed.
is there an aluminum alloy which is a bit more flexible?
maybe there are indeed fine vibrations that cause the crack?

regards
Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
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JanBros
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Re: hairline crack on the engine mount

Post by JanBros »

who did the welding ? it doesn't look like a pro did yours. those tiny little holes on the surface mean there will be also like those on the inside and they are weak spots. a good welder doesn't need to grind the welds away, a good weld is nice to see.

I also have to grind my alloy welds away :cry:
My ultimate goal is to die young as late as possible !
dirk
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Posts: 342
Joined: Mon Jul 30, 2007 8:18 pm
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Re: hairline crack on the engine mount

Post by dirk »

Thanks for your explanation


the welder is master mechanic.
i myself have have no idea of welding.
i do not see it whether it is good or bad :oops:

dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
dirk
Heavy Smoker
Posts: 342
Joined: Mon Jul 30, 2007 8:18 pm
Location: Germany

Re: hairline crack on the engine mount

Post by dirk »

Hi All

So here is the second attempt .....
does not look nice, but I hope it no longer breaks.

Image

regards
Dirk
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
dirk
Heavy Smoker
Posts: 342
Joined: Mon Jul 30, 2007 8:18 pm
Location: Germany

Re: hairline crack on the engine mount

Post by dirk »

step 2
a new spacer.
the original spacer was 25mm long.
it lacked 1mm
after welding the engine mount has moved 0.5mm to the outside.
the holder on the engine itself is only 7,45cm.

Image
KR-1S 1990
RG500 1987
RGV 250 1992
TZR250 (2MA) 1987
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