Anyone there that knows something about XJ's?

Ha -I knew that would draw you in. Hello, I'm real close to building the bike I've always wanted. Been runnin a 750 Seca forever but always liked the idea of the 750 motor in the 650 Seca. I've been all over this site & I know its been done before. I've got a chance to buy a 650 in pretty good shape, 46K on it. My 750 Seca currently has a motor from a 750 Midnite Maxim & plan on using this motor for my project. Any tips, hits or advice would be greatly appreciated. Thanks for your response, & oh yeah, I'm gonna run pods!

 

Did some one mention Pods

 

PODS!!!!!!!!!!!!!!!!??????????????????????????????!!?!?!?!

 

OOPS! Didnt mean to start a pods war here-was just tryin to interject some humor in the post. Seriously, I'm open to anything at this point-depends on how things fall into place. About eighteen inches of new snow here-Dang!

 

MAN Pods look awesome!!!

 

I've only met a few (less then 5) builders that have had total
success with tuning pods.

But they look great!

Good luck.
ron

 

from Chacal's information overload hour http://xjbikes.com/Forums/viewtopic/t=27544.html

* when putting an XJ750 engine into a 1982 650RJ Seca frame, please observe the following changes:

- have to convert tachometer to an electrically driven version.
- the original XJ650RJ oil level sender needs to be retained (unless the engine is from a 1983 750 Maxim or Midnight Maxim)
- the 650RJ shifter side cover and all internal components are the same as those in a XJ750 Seca engine. The 750 Maxim style shifter may not work.
- all engine mounting hardware for the XJ750 Maxim engine will need to be used (no rubbers on Seca engines; an XJ750 Seca engine uses the same mounting hardware as the XJ650RJ Seca, except for the front upper frame brackets, the XJ650RJ Seca frame brackets should be used. If using an XJ750 Maxim engine, you'll need to be creative.............
- will need to use the XJ650 airbox boots.
- will need to use XJ750 carbs (or re-establish the XJ650 carbs to XJ750 specs).
- need to retain the XJ650RJ exhaust system
- need to retain the XJ650RJ wiring harness, except for the pick-up coils sub-harness. The pick-up coils on the XJ750 engines are different. Need to use the 750 TCI box.
- when using an XJ750 engine, be aware that there is a slight gearing difference----while both the XJ650RJ Seca and the XJ750 Seca models used a 18" rear wheel, the XJ750 Maxim models used only a 16" rear wheel, and thus the middle drive gear ratios are slightly different inside the tranny on some engines. Thus there will be a difference in the acceleration of the bike, depending on which donor engine is used.

 

All right!! That is exactly the information I was looking for. I'm still learning to navigate around this site. In the meantime I may be asking for help like this. Thank you very much for your time, Maverickbr77. You guys are great!

 

Educate yourself before committing to altering the Intake System and abandoning the Airbox to install Pods before making your decision.

Get a Workshop Manual: (somehow).

 

no problem. Take the time to look through the other information posts by chacal in the xj4ever section it was one of the first places the fine folks here sent me too and it is a great place to get some info.

 

and if you decide to do it after educating yourself on what you are getting into for goodness sake destroy as little as possible. Remove the airbox(s) in one piece and save them so you can go back or if all goes well heck, you can sell 'em.

look over the cut/pasted list Mav posted. I'll admit I only skimmed it but I see right off the bat a few things that apply to a simple swap but may be altered with more customization. IE the bit about tach conversion assumes keeping the 650 tach as opposed to running the one from the 750 or transplanting some guts from the 750 into the 650 housing or getting an aftermarket. The bit about exhaust assumes no aftermarket is being used (which, if you're podding you may as well 4-1 too)
Anywho it's a good guideline but check it over and think everything through.
Ya know what they say failing to plan is planning to fail.
or if alliteration is more your thing, Proper planning prevents piss poor performance.

 

WWj750,
Why don't ya just wait till ya get that frame from me and save yourself some work. Atleast that way you'll know the enigne will fit without any problem. The frames are about the same size so you won't be gaining anything by using a 650 frame and it would just be more work.
Just sayin'. PD

 

I like that plan better because when it came time to finalize the deal the guy jacked up his asking price $200 more. Thanks to all for the all great info. I will save it for future reference.

 

Ya, I just love it when people change their mind at the last minute.
If nothing else, if you need it sooner, we can work something out and I can deliver it with my pickup or you could use my trailer if you have a hitch. I would need help to load it is all.