Topic: '78 F3 engine into a '76 F1?

[sirdaft1]

How plug and play would this swap be?

[Don R]

Carbs are different and the sprocket offsets and sizes are different. Either carbs with the correct airboxes should fit. You will need an offset 530 front sprocket I think.

[Tugboat]

You will need a 10mm offset rear sprocket form CycleX. 530 front sprocket and chain. And if you use the later carbs, use a later air box and boots as well.

[sirdaft1]

So front and rear sprocket and chain, for sure. And I maaaay be able to use the F1's carbs and airbox on the F3 engine? Or should I plan on getting new carbs as well?

[Tugboat]

No, I think that as long as you use "same year" carbs/boots/airbox it will all line up. Or is it that you have to use the intake boots that are correct for the motor, but the carbs & airbox & airbox boots all have to be the same? Somone confirm pls.

Otherwise, everything else lines up. Just remember that the front sprocket on the later motor is 10mm offset (wider) than your rear sprocket using this setup, so you'll have to offset your rear sprocket in order to compensate, or your chain won't be straight and will wear out very quickly. The CycleX 10mm offset rear sprocket will bolt right on to your stock '76 rear wheel, but it's a 530 sprocket, so you'll need a 530 front sprocket and chain to go with it.
At the bottom of the page:
http://www.cyclexchange.net/Chain%20Sprocket%20Page.htm

[sirdaft1]

Thanks guys!

[MRieck]

Yesterday I fitted 78F2 cases with the F2 output shaft and had to remove a good amount of material from the back of the 530 counter sprocket for proper alignment and fitment. The frame is an 75F. I do not see how that offset counter sprocket would work. Actually....it would never work (being blunt).