Yamaha YZF R125 Forums banner
1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
I am in the process of replacing a 2009 model engine with a 2014 engine - Although it looks like for like does anyone know of any mods that may be rquired
 

·
Super Moderator
2008 YZF-R125 (180cc)
Joined
·
658 Posts
That could be...interesting - gen2 has a different intake port bolt spacing, intake manifold & throttle body for starters, and the gen2 throttle body isn't compatible with gen1 wiring (as far as I know). It looks the same but once you go to fit it the holes don't line up. A friend recently tried to fit gen1 kit to a gen2 motor recently and discovered how badly it didn't fit.

Also the gears work the other way around, though I guess you ought to be able to fit a gen2 shifter.

There may also be wiring differences but haven't got a gen2 so can't really comment further.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
That could be...interesting - gen2 has a different intake port bolt spacing, intake manifold & throttle body for starters, and the gen2 throttle body isn't compatible with gen1 wiring (as far as I know). It looks the same but once you go to fit it the holes don't line up. A friend recently tried to fit gen1 kit to a gen2 motor recently and discovered how badly it didn't fit.

Also the gears work the other way around, though I guess you ought to be able to fit a gen2 shifter.

There may also be wiring differences but haven't got a gen2 so can't really comment further.
Thanks for the input - you right on the above. We have successfully got it back together using the old Throttle body and the new gear lever all with original wiring etc apart from the exhaust sensor. Would be good to get comments if anyone else has done it. We will update once we get the fluids in etc to see how things will run
 

·
Super Moderator
2008 YZF-R125 (180cc)
Joined
·
658 Posts
oh nice going! I'd heard rumblings that somehow the gen2 heavy metal was better than gen1 but never got any more specifics, and people do seem to think the gen2's go a bit better, so i'd wondered about using a gen2 as a base, but given the differences seemed like too much of a gamble. Once you've got it running it might be good if you ccould document/post the problems you faced and how they were solved. It would be good for all of us to know exactly what the differences are. good work!

Did you redrill the head to accept the gen1 throttle body then?
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #5 ·
Hi ok
where do i start ? i bought a yzfr 125 as a project . The bike would start but would not take the throttle. I put it to an auto electrician who checked all the wiring ,replaced the fuel injector and changed ecu still no change. I put it to a garage and they said the compression was low , i purchased a second hand engine for them to fit and was told the compression was low on that one also, i took the bike back as i was not convinced that the diagnosis was correct. I then bought a gen two engine with low miles from a running bike .i fitted the engine using the gen 1 throttle body on gen 2 manifold . low and behold the bike starts but will not take the throttle. again changed injector and ecu no change .
Any help would be appreciated
Regards
Eck
 
1 - 6 of 6 Posts
Top