To 750 or not to 750?

[HxNutMike]

I picked up an oily '81 XS Special and have the engine out for future work while I clean up the frame, polish the cases, do some work on the tank, try to figure out what paint I want, and so on. I am trying to decide if going the 750 route makes sense. After all, all the gaskets are going to be replaced, so those can be done and the 650 retained or I can go the 750 route.

I'm asking for some comments from those of you who made the conversion--I've read some of the threads about this, but I hope to get some recent comments as well. Was it worth it or was the vibration too much? I'm not so much interested in going fast on my XS--the Triumph Rocket 3 is for the fast stuff--but I do want a non-leaking, semi-reliable, classic bike that'll do 55 without vibrating itself or me too much. Plus, it's nice having a bike I can still work on!

Thanks in advance for your comments, help, and guidance.

 

[Mailman]

Here is a recent conversion done by @GLJ , he was sure happy with his.

https://www.xs650.com/threads/its-past-time-to-start-xs2-resurrection.53396/page-29#post-745764

 

[motormike]

I've done a few 750 bore kits.... sleeved. Not a fan of the big juggs offered by Mike's... I feel it hurts the look of the engine. It's pretty much straight forward .... any machine shop can heat, drop old sleeves, bore... heat insert new sleeves.. bore to piston and then feck the top. Any bigger would require welding the cranks. I never did a Special and seem to recall they have smaller intake ports... I could be wrong.... and wonder if that would be affect performance.

 

[JesseeS]

I installed a 750 kit in my bike. While the bike is still being built, ive had the motor running in the bike. I have not ridden the bike yet. On the side side and while revving it appears the bike actually vibrates less. Meaning while on the side stand its not dancing as much as compared to 650 form and when revving the bike doesn't walk the side stand. I also notice less vibes from the bars but my front end is far from stock so YMMV. Again, no ride data yet but static observations. Greater displacement in my opinion isnt ever a bad thing. Welcome from another CT local.

 

[WideAWAKE]

Bike definitely vibrates less.

You are no longer cruising is the typical buzz zone.

Higher speed at a lower RPM.

I think the early bikes are well served with their 650 motor - 75 onward should all be 750s. At least that’s my take on it.