1978 Motor In A 1970 Frame?

[heypilch]

OK, here's my question for all the experts out there...

I've got a 1970 frame that's been hardtailed, but it's just a roller. I finally found a bitchin complete motor for it, but it's out of a '78. Are the mounting points the same, or will I need to figure something out to make them line up?

Also, what brackets are you guys running (other than stock)?

Thanks for your advice
Tim

 

[angus67]

mounting points are the same, but you need the mounts for a 78.

 

[neanderthal]

mounting points are the same, but you need the mounts for a 78.

you need the mounts for an early frame I think 70-73 are the years. someone will correct this if im not right. Not sure if there are any custom mounts for the earlier frames, never looked and have only had two early frames, but used stock mounts. Someone one here could produce some for you im sure. I should have most of the mounts. I think i am missing a part from the top mount is all.

 

[NONclow]

The only prob I had was enlargening the holes on the front mount that connect the mount to the engine. BTW all my mounts are standard '71 pieces, exept for the two larger holes on the front mount on either side of the case.

 

[neanderthal]

the front of the frame of the earlier models were more narrow than the later too. Ive turned later mount into earlier ones by cutting and welding. not difficult by any means.

 

[XSLeo]

The 70-71 engines didn't have the E-start. In 72 they added the starter. This made changes around the rear mounts. So if you use a 70-71 frame with a 72 up engine you need to fab up rear mounts.
In your situation I might install the engine, put in just the bottom center engine mount bolt, See if the lower rear mount bolts hole in the case lines up with the lower rear bracket on the frame. If it does then just fab up the rear mount plates as needed to fit from engine to frame. Then do the same for the top and front mounts.
Leo

 

[heypilch]

Thanks for all the advice guys. I knew I wasn't going to get off too easy on this build haha. This is the 1st XS I've ever built & have never built anything from absolute scratch.

Once I get the two together, I'll send this old frame to powdercoat & do a springer front (after ditching all the stuff in the pic). This is the all this frame came with, so it needs everything - kind of a good thing in a way cause then I can do this build any way I want to.

Should look good with this motor in it. Just finished cleaning it up and painting it. New shiny parts are on the way

 

[heypilch]

I don't who's bike this is, but it is Superbad. This was what made me decide to paint my motor. Can anyone tell me who makes that springer?

 

[NONclow]

The 70-71 engines didn't have the E-start. In 72 they added the starter. This made changes around the rear mounts. So if you use a 70-71 frame with a 72 up engine you need to fab up rear mounts.

True. The 72 IS the first year for E-start, comp release, disc brakes, etc.

The only prob I had was enlargening the holes on the front mount that connect the mount to the engine. BTW all my mounts are standard '71 pieces, exept for the two larger holes on the front mount on either side of the case.

In your situation I might install the engine, put in just the bottom center engine mount bolt, See if the lower rear mount bolts hole in the case lines up with the lower rear bracket on the frame. If it does then just fab up the rear mount plates as needed to fit from engine to frame. Then do the same for the top and front mounts.
Leo

Yup. One bolt at a time.

Stock/modded/custom mounts aside, like the pics show, I've successively replaced a '71 motor with an '80, all 5 stock '71 mounts (including the modded front), E-start also!

 

[neanderthal]

DNA makes the springer. Research it before you buy it. This forum has plenty on it.

 

[heypilch]

DNA makes the springer. Research it before you buy it. This forum has plenty on it.

Thanks, I will man.