OzVMX Forum

Clubroom => Tech Talk => Topic started by: suzuki447 on July 20, 2010, 06:31:27 pm

Title: 76rm125 query
Post by: suzuki447 on July 20, 2010, 06:31:27 pm
hi guys can someone tell me if i m doing this right im putting rm125 engine back together turns out someone put pe175 big end in it while they were rebuilding it but small end bearing to big for 125 piston ,anyway i split motor (first time for me but i,m looking at a spare engine to copy everything )put right size big end in ,is there a special position for gearshift cam to be in prior to closing up gearbox,thanks don.
Title: Re: 76rm125 query
Post by: JohnnyO on July 20, 2010, 06:56:41 pm
Have it in neutral so both gearshafts spin freely
Title: Re: 76rm125 query
Post by: TM BILL on July 20, 2010, 07:07:44 pm
Are you sure itwas the wrong small end  :-\ 125A runs a 16mm gudgeon but all other air cooled RM125Ss run a 14mm gudgeon  :)
Title: Re: 76rm125 query
Post by: suzuki447 on July 20, 2010, 09:48:17 pm
yea it had 19or 20mm which is same as my pe175 i checked ,the bottom end the same but conrod  different ,so split it and changed to right size ,thanks don
Title: Re: 76rm125 query
Post by: suzuki447 on July 20, 2010, 09:50:35 pm
ok thanks tm,bill will do .
Title: Re: 76rm125 query
Post by: TT5 Matt on July 21, 2010, 12:05:43 am
tm125 rm125m/s rm125a all ran 56mm piston's only difference is rm125a used a 16mm piston pin's where the other two used 14mm pin's ,rm125bcn used a 54mm piston with 14mm piston pin's. the rm125a's are the hardest to get piston's and rod's for but some people put b model cranks rod's and piston's in their A model's but not sure about the barrel/head but someone that's done the conversion should be able to shed some light on this matter