8valve gs750 motor in a 16valve 81gs750

[Dphillips030]

I have a 81 gs750. It's the tscc 16valve but the motor is shot. I am thinking of putting an 8 valve 750 motor in it. Any thoughts/ideas/complications with this? Will the cv carbs match up on the 8valve motor?

[eil]

I don't think this will be an easy swap. For one thing, I do believe all of the 850s were shafties, which is a showstopper itself. The CV carbs are just about the same, but jetting will be different of course.

Unless you have a hankering for fabrication and enjoy making square pegs fit round holes, I would just get a new second-gen 750 engine or even better upgrade to an 1100.

[78550GS]

I don't think this will be an easy swap. For one thing, I do believe all of the 850s were shafties, which is a showstopper itself. The CV carbs are just about the same, but jetting will be different of course.

Unless you have a hankering for fabrication and enjoy making square pegs fit round holes, I would just get a new second-gen 750 engine or even better upgrade to an 1100.

I don't think he said he was looking to put an 850 engine in?

I can't comment further, other than 7/11 swap would be my choice.

[JTGS850GL]

Yep, I'd do a 750 16V to 1100 16V engine swap in a heartbeat. I'm pretty sure you'll be looking at motor mount fabrication as a minimum with a 16V to 8V conversion. You'll also loose some performance as well.

[eil]

I don't think he said he was looking to put an 850 engine in?

I can't comment further, other than 7/11 swap would be my choice.

Whoops, yes, I didn't read the question closely enough.

[Dphillips030]

Think I'm going just drop a 16v 750 back in it. Think I've found what I need to get it back running right. I am going to keep my eye out for an 1100 though. I've read they will fit up with no hassle. Thanks everyone

[eil]

I just wanna say, the 16-valve 750E engine is no slouch. This morning I rode to work via a short stretch of curves rated at 40mph. I was stuck between a car doing 30mph in front and an impatient tailgater to the rear. Coupled with roads that have not yet been washed of their winter detritus, I got a little nervous. So I did the only thing I could... first chance I had, I whacked the throttle open to zip around the slow car. Looked down for a second and was just plain shocked at how quickly 65mph had snuck up on me.

[chef1366]

Check replacement motor for purple cams.
Just saying

[Dphillips030]

Purple cams? Is that evidence of it being a drag bike?

I picked up the bottom end of a 16v 750 from member JamesWhut earlier today. I should be able to get it back running right with that

[JamesWhut?]

I think he means camshafts heat discolored from top end lube starvation.

[akckhim]

I think he means overheated or scorched cams

[JamesWhut?]

Ya owe me a coke.

[Jedz123]

The 8V 750 motor is chain drive yes but the case is longer to accommodate the kick start and will not fit in a 16V frame. My engine finally went in my GS750L and I did a 7-11 swap...

It's going to cost a tad more for an 1100 engine but it's worth it. Also not sure if it's economically possible but a gen 1 GSX-R or Gen 2 Katana or Bandit SACS engine can fit in a GS frame with little modification. I've thought it would always be cool to put a GSX750F engine in a GS750 frame...

Or another option is just save your pennies and do what I did after my 750 went past it's prime. Buy a GSF...