750cc to replace a 650

I've read a couple time that the 750 is much more powerful than the 650 , and is a straight fit in a 650.

I own a 1983 xj650 , and a parts bike just pop-up on a add near my place , a xj750 1985.

How easy is the swap ? Do you really simply put the other engine in place and use the same coils , etc ?

EDIT: I just realised it's a maxim-X , soo watercooled.... thoughts ?

2nd Edit: Now that i think about it i would prefer to stay aircooled , so a 'normal' xj750 would do it... What are the reviews of the watercooled engine , i didn't even knew that made those !

 

Swapping a 750 air cooled engine into a 650 frame is easy.
Swapping a water cooled 750X engine into a 650 frame is hard. You can read about it here.

 

a 5 valves per cylinder Rocket. valve shim replacement is much more involved but there is quite a longer maintenance schedule for the shims

might be better to fix the x than swap the motors

 

The Maxim-X is collectable. Buy it, restore it, ride it, and if things go well you might get to pad your retirement fund when it comes time to sell.

 

The 750 X is missing the gaz tank and the seat , are they unique to the maxim-x ?

The guy is asking close to nothing for it , how much a good condition one might go for ?

I'll probably try to find a 750 aircooled for mine.

I also see there is 900 and 1100 engine , but i've never seen any thread about swapping those ina 650 frame

 

A restored X can easily fetch above $2,500 U.S.

The 900 is taller and will not easily fit into the 650 frame. You will likely need to remove the engine every time you have to check the valve clearances.

The 1100 engine is a very different beast and much larger in all directions. It will not swap into your frame.

 

"* when putting an XJ900 engine into a XJ650 Maxim, Midnight Maxim, or RJ Seca frame, please observe the following changes:

- it can be done: http://xjbikes.com/Forums/viewtopic/t=29398.html

The same guidelines as generally outlined in the XJ700 engine swap should be observed."

"* when putting an XJ1100 engine into a XJ650 Maxim, Midnight Maxim, or RJ Seca frame, please observe the following changes:

- put down the tools and the torch and back s-l-o-w-l-y away from the bike.
- 1100 engines are vastly different than the other XJ650/700/750/900 engines in design, style, size, etc., and attempting to put one of these engines into the smaller frames is likely to be a complete custom job. No other information is available. It would be wise to consider buying an XJ1100 model bike, and riding that, rather than trying to transplant just the engine....."

 

Thanks for all the informations !

I'm used to do rather complex engine swap , but not on motorcycles.

My 650 burn quite a lot of oil , instead of rebuilding the engine , i'm looking for a cheaper to swap than to restore engine.

I'll probably just wait to find a cheap 750 air cooled in good shape.