Can I put seca heads on a maxim?

I need a new head for my 83 maxim 750. The previous owner was quite abusive with overtightening bolts and there's too much broken off or helicoiled - I don't trust it anymore.

All I can find on eBay are seca heads. I know that it ran a hotter cam (though my cams are still good so I can swap them), otherwise are they close enough that I can bolt it up? Are the base castings the same if I want to put my cams in?

 

Yes, yes and yes. Check out the Tech section by clicking on the xjforever banner on the top right of the page, this is like the online bible of the XJ bikes and written by those in the know.

 

So long as you're not swapping between yics and non yics...

 

Biggest difference is SECA is a solid mount engine and the Maxim is rubber mount

 

1981-82 XJ750 Maxim and XJ750 Seca (1981-83) heads and cams are all the same, so no need to swap cams. 1984 XJ750 Seca heads are a bit different in their cams (they use the XJ700 exhaust cam) and a slightly larger intake valve..

 

Will the head assy itself bolt to the earlier 1981-1983 jugs and run the same chain?

 

Somebody please correct me if I'm wrong - but I do not think the XJ750 ever came with a non-YICS head.

 

You are correct.

And to answer the earlier question, it (1984 750RL head) will only fit the YICS heads and will use the same cam chain, head gasket, etc. as earlier 750 engines.

 

Sounds like an upgrade

 

The 750RL models also used the larger HSC33 carbs........

 

Think I can make it work.

 

With a big enough hammer........anything can be made to work

 

Sometimes that hammer has to be made of money though....

 

Those are the best kind.......

 

So going thru the engine info on the XJ Forever page it appears that the 750RL head would be a direct bolt-on and fully compatible with the 1981-1983 XJ750R bottom end. It was mentioned the RL used HSC33 carbs but given the flow of the 32's I don't see those a detriment in the big picture in this case, we're not increasing the overall displacement only the VE of each cylinder. In short if I could find a good affordable head I'd do the swap on my SECA and ride into the sunset then post the results on the forum. My SECA could use a valve job and this would be a bonus.