RM400 Motor N,T,X

[Power Stand]

Can someone advise what year this RM400 motor is; serial number 105606

Also do the frames differ between RM125, 250,400?

For example I have a RM400 motor and if I find any old frame will the 400 fit in to a 125, 250. Obviously I would need to beef up the forks and shocks.

Cheers Pete

[Power Stand]

OK found this post,,,on frames.
http://ozvmx.com/community/index.php?topic=14572.0

Basically a 250 & 400 are compatible but is this the same for 79 & 81

[DR]

Pete, I think the motor you have may well be a 1978 RM400C. Easy to tell, the 2 rear most cylinder mounting nuts below the inlet mainfold..8mm studs for the RM400C and 6mm studs are RM400N/T.

417cc RM400N verses 402cc for the 400C

If it is a C then the '76-'78 RM250/370/400 A,B and C frames will work as would PE250C or N

[bigk]

Where's the clutch arm? RHS in the clutch cover (C) or LHS in front of the sprocket (N/T).
K

[Power Stand]

Thanks Doc & bigk, the clutch shaft is on the left next to the sprocket & barrel rear / reed induction bolts are 6mm. I found a site that recons by serial number it should be a RM400C but the whole engine is identical to my PE400T except the PE differences like fining dampers etc.

Now I need to get a roller to make a loving RM400N or T

[LWC82PE]

81 RM bikes are mono shock and totally different motors and frames. The 81 is also a 465

No RM400 motor is identical or inchangeable with PE400 in anyway, different stroke and bore size ete. They only look 'similar' in that they are both air cooled suzuki motors.

105606 is one of the last 1978 C models but that doesnt agree with what the others have said about bolt size and clutch arm side

If you want to be 100% sure what year the motor is, just ring up a suzuki dealer. Its the only way to 100% know what it is and i dont necessarily believe what the charts say.

[DR]

she be an N alrighty
 
400C 100001 - 105264 
400N 105265 - 109711   
400T 109712 - RM465

[lukeb1961]

If you are interested, I've put a few RM400N and RM400T articles up on my Skydrive
http://cid-407d7ef0965d3991.office.live.com/browse.aspx/Racing%20Model/Magazines/

Luke

[Power Stand]

Thanks again, I raced a RM125N back in 1980 to 82 and it was my first proper MX bike. I had a number of Suzuki models over the years and they were all great bikes.

If I could build a RM400N I would be happy as.

Luke, that collection of information is outstanding and invaluable info,,,, to see what you have done only provides a legacy for the future and if it wasn’t for people like you collating this info so much would be lost
Cheers Pete