XJ650 maxim jug swap

Alright fellas, just found out my base gasket is leaking. And I thought. If I'm gonna rip it down and replace it. What all jugs will fit. I believe a 750 jug will right? Will the pistons go straight into the rods? And is there any piston/head clearance issues. And if the 750 jugs will work what about punching it out to the 818(?) big bore kit with the factory bottom end and a 750 head. My head is already kinda messed where the bolts go in anyway. So basically what I want to know is will this work.

650 bottom end.
750 jugs-possibly with a big bore kit.
750 head.

Or

650 bottom end
750 jug
650 head - possibly with 750 cams

I know carb rejecting would be in order. Yada yada. But I would like to maximize the power and upgrade if I have to rip it a part. I'm not concerned about the price of parts because I have already priced them. Mainly just, the big stuff. Ya know? Hopefully someone has some info on this! Thanks!

 

Would love to see an answer to this as I have considered the same things with my '82 daily rider. I've got 650 and 750 Maxim parts bikes with good running engines and have wondered what can be mixed and matched.

 

Well. I'm about to swap in a 900 jug and 750 cams. So I guess I'll let ya know how it turns out.

 

Cool. I'm tempted to put the entire top end of the 750 onto my 650 bottom. I'm not real concerned with performance increases, there's an ugly/faulty repair job on my 650 head and since I have this 750 just layin' here.....

 

If you have a 750 laying around, why not just switch motors?
Layitdown: not sure the 650 bottom(crank) will handle that much change.

 

Well, I guess we will see haha. At worst I can always put my 650 jug back on it. Unless of course the bottom end comes apart. Which I honestly doubt it will. I've seen where people have done it before with good results. So hopefully mine will turn out well also.

 

I hope it works out too. There was a similar discussion in another thread not long ago about the big bore kits and the effects on the crank. Most felt that too big of a jump in cc's would be a strain on the crank. Could be that Yamaha's cranks will handle more than we think. Let us know how it goes and don't forget the pics. 8)

 

Yea. It makes sense. But I tend not to turn engines up quite as high as other people do. A friend of mine turns his to 12 or more on a regular basis. Not saying it's a good idea. But be has had zero problem outta it. So I assume if his stock one will take that so will mine if I keep her under 9.

 

Ask Len Chacal....he'll give you all the info you'll ever need--and more.

Dave F

 

Who is that?

 

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