Which Engines Fit Which Frames?

[caseyfiedler]

I've been searching the forums and can't find a very comprehensive insight into which engines can be swapped into which frames. I'd really like to get a kick-only engine which is '72 and older, correct? What was the first year Yamaha produced the XS650 kick start engine, and can some confirm that the '72 model was in fact the last kick only year? What year frames will these engines fit into and what is involved in making the swap work? From what I've read it's rather simple but I'd like a detailed explanation from someone, please!

You all are so incredibly helpful!

Thanks so much!

 

[650Skull]

kick start started in 1970 XS1.

You would be better to tell us what you have so an explanation would be less general

The search at the top left is what you need to look at, I copied your heading into it and come up with This Link. Do some reading and come back with questions.

There are so many variations from 70-83 it would would be an essay to explain the lot

 

[caseyfiedler]

Thanks, I've been using the search bar on the right. The left hand search bar seems to yield more useful results. Thanks!

Posted via Mobile

 

[5twins]

'70 and '71 were kick only. '72 was the 1st year with the electric leg. Something else you should consider are the 2 engine types. The older engines up to '73 were what's called the "256" type. '74 and later were a new version, the "447" type. There were many internal changes. The newer motors are cheaper to get parts for and by most accounts, more reliable (bigger piston wrist pins). You can pull the starter out of any motor so equipped and make it "kick only" if you like. Any motor will mount in any frame using that frame's engine mounts. Engine mounts changed slightly as the frames did so you need matching mounts (to the frame).

 

[gggGary]

The newer 447 motors use a smaller wrist pin. That allowed more metal around the pin in the rod and ended a rod stretch problem the early motors had under hard use. The front mount bolt hole and casting in the 70 and maybe 71 engine is in a slightly different location than later motors. So unless you are restoring, as 5twins suggests the 74 and up 447 motors with the starter removed probably are your best choice. MikesXS sells a block off plate to make starter removal easy.

 

[caseyfiedler]

Thanks so much, these were really helpful responses. Do the 447 motors have a decompression lever for kick starting?

 

[650Skull]

No, they were on the 72 XS2 and 73 TX only

 

[5twins]

Yes, I got my facts a bit mixed up there, lol. But what I was getting at was the wrist pin wear. It can be a problem on an early motor that is pushed hard often. And then the parts to fix it cost more and are harder to find. I have an early motor and hope maybe to transplant the cam into a later 447 someday. That's about all I'd like from it.

 

[plane_ben]

I had an XS1 engine about two years ago. Turned over and had good compression. I don't know what got into me when I let it go.