Topic: k8 Engine in a k5 frame?

[siter81]

I am thinking of swapping my k5 750 motor out with a k8 while i get the k5 rebuilt.Will i have any major issues like my carbs wont fit the k8 etc? Wiring woes?

Thanks too all replys.

[eldar]

Since they are both K motors, you should not run into any real issues.

[phylo101]

Carbs might be an issue, the later Ks, 7/8/9 had a larger and reshaped front sirbox, the plenum chamber bit. And the bore size of the carbs was different so the rubbers will be different, ans their holes in the airbox. You may have to go to cone filters and rejet in the interim.
I think I can recall being told ages ago that from the K7 on a couple ofnthe engine mounting brackets were different, you'll have to just ry it and see.

phylo

[eurban]

One thought here . . . .For the most part the K8 engine has more refinements and should make a bit more power than a K5 engine.  (upgraded clutch, slight compression bump, slightly hotter cam etc etc)  Maybe you should rebuild it instead?   . . . .I am fairly sure that with minimal effort you should be able to mount up your earlier carbs to the K8 engine.  The K8's exhaust is flanged and uses studs to mount up rather than eariler spiggot type setup but you can remove the studs and mount your K5 engines spiggots to the K8's head with k5's bolts.  I don't know about differences in engine mounts?  Good luck

[unlucky71]

I have K1 carbs on my K8. Early K carbs are actually better running carbs than they put on the K7-K8. You have to take off the K8 manifolds and replace it all the way back otherwise they won't fit. Getting those things off really sucks by the way. Good Luck! 

[luckysox]

I believe the drive chains are different. The Ko to K6 had a 530 chain and the K7 K8 had a 630 chain.  Changing sprockets can be a pain unless you use aftermarket sprockets. The out put shafts are not the same from the earlier K's to the later K's. Good luck