Suzuki RM125 1977 & 1978 cylinder difference

narrowfarm
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narrowfarm
Hello, does anyone have info on the difference between the 1977 and 1978 RM125 engine cylinder???
Is there a physical difference in the ports that I can see?? Thanks
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MaxPower
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MaxPower 7/10/2019 8:15am
7/10/2019 8:15am
I always thought that they were identical.
Can you check if part numbers were the same?
BRT771
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BRT771 7/10/2019 3:12pm
7/10/2019 3:12pm
The Suzuki part number show the same cylinder 1975-1978.
riv187
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riv187 7/15/2019 9:48am
7/15/2019 9:48am
narrowfarm wrote:
Hello, does anyone have info on the difference between the 1977 and 1978 RM125 engine cylinder??? Is there a physical difference in the ports that I...
Hello, does anyone have info on the difference between the 1977 and 1978 RM125 engine cylinder???
Is there a physical difference in the ports that I can see?? Thanks
78 the exhaust ports widened at roof, like 2 trapezoids as I remember. Ported they make the trapezoids even wider. \.| |./
Lonestar_399
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Lonestar_399 7/16/2019 7:57pm
7/16/2019 7:57pm
Like Brian said the porting is different. I'll pull a couple and try to get some shots to show.

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narrowfarm
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narrowfarm 7/17/2019 4:16am
7/17/2019 4:16am
Thanks , I got a cylinder from someone who does know what year it is.He was told it was for a 1976 but It doesn't fit his bike, looks more like a '77 or '78,
DaveB771
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DaveB771 7/17/2019 8:36am
7/17/2019 8:36am
The 1976 RM125 had a 56x50 bore/stroke. The 1977-later engines are 54x54. I don't remember the 1977 and 1978 engines being externally different, but that was a long time ago.

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