Simmy's Naked Turbo Project

I've been dreaming about this project, going on now for about 33 years. I finally made the commitment to start this project with my latest acquisition. I plan to continue this thread and post any updates to the build here. I found an unmolested 82 XJ650LJ Turbo with relatively low mileage (36,000 kms) that's been sitting in a garage the last 15 years. Apparently it began smoking terribly so was just parked. He said it ran and idled fine but would fill the neighborhood with smoke so that suggests oil is leaking past the seals in the turbo unit. I'm hoping I can get the turbo repaired, I've seen the options Chacal lists and also plan to start replacing all the rubber parts in the carbs. To be honest without knowing of Chacal's parts availability I might have shied away from this altogether. So step one will be to just get this thing running soundly. What I really have in mind is a Seca Turbo that looks like the 82 XJ650RJ Seca with a few custom touches, 16" wheels being the most obvious change. I also bought a very shabby XJ650RJ donor bike. Although what I need are good cosmetics this bike will enable the mock up to proceed.

88 FZ600 on the far left will donate the front forks, fender, wheel and brakes.
82 XJ650RJ will supply big 9" headlight, clocks, tank, seat tail piece and side panels.
I'm envisioning putting the 2 bare frames side by side and transferring any brackets from the standard Seca onto the Turbo frame, and also cleaning the Turbo frame up to eliminate all the unneeded fairing brackets. This is going to be a long term project. It sounds straight forward but anything like this will always throw curve balls.


My son says the Turbos is way cool and can't understand why I want to make it look like the Plane-Jane bike sitting next to it. The Turbo's cosmetics are actually in great condition and I feel just a tiny bit guilty bastardizing it. No offence to all the Turbo owners but most anyone's top 10 ugly bike list includes the Yamaha Turbo.

In 1984 I was a 23 year old hooligan with a brand new Seca Turbo. I rode it 5 years and 75,000 kms. Rocket boy styling was never to my liking. 33 years later I'm lugging another one home, this one I'm doing up the way I want.

Donor Seca in real bad shape. Shame really as it shows only 29,000 kms on the clock. The headlight and instruments are hard to find now days, actually any parts for them are rare. This one has the electronic tach, oil cooler and YICS. Seat is aftermarket Travelcade. Tank is real rough and I'm not sure if it will be salvageable. I will be on the look out for a good one. If it was in better shape I could stick all the Turbo body work on it but who wants to ride a sheep with wolves clothing? It even has the original Yamaha chain lock, unfortunately it came without keys. When I had my Turbo new I wrapped that silly chain through the back wheel. I forgot about it and when I moved the bike off the centre stand the chain broke. What a joke. I've already forced the seat and tank cap open with a screw driver. The tank still has some vile liquid in it and doesn't leak, perhaps it can be salvaged.

 

Vile liquid? Sign me up!

 

The 650 turbo shares the same basic frame as the 650 Maxim, with the necessary bosses welded on for the additional stuff for the turbo Seca. I am NOT sure how closely the non-turbo frame lines up with the 650 Maxim frame, though I suspect it's pretty much the same except for saddle mounts, side cover points, etc..... So I'll be watching this with interest.

Dave

 

That huge gas tank on the Turbo might be a challenge to get rid of....... I think it would be easier to swap the turbo engine and wheels, etc. onto the 650RJ frame. Figuring out the electronics (which can stay and which can go) in terms of the knock sensor and the pressure sensor might be a challenge............I think those go thru the "computer" in the Turbo dashboard, and surely you want to get rid of that?

I think that the turbo uses a beefier swingarm (more gussets), and fitting the turbo surge tank/air cleaner apparatus onto the 650RJ frame might also require some effort.

I really like the idea and perhaps you will start a new trend in the XJ world. The RJ Seca is a fun, comfortable, and well-balanced bike.

 

Thanks for the replies guys. Chacal I'm curious why you think it would be easier to convert the RJ frame to accept the Turbo versus just changing the cosmetics of the Turbo? What about the tank? Does it allow a recess for the fuel pump or something? All I was aware of was the different petcocks. The electronics I realize are going to be a challenge. Simply changing the tachometer can play havoc with the ignition on some bikes. I'm tempted to simplify the wiring as much as possible. I have lots to learn here. The RJ has no ownership, not impossible to overcome here in Ontario. If for good reason turbo-charging an RJ is easier I won't rule that option out.

Dave I thought the Maxim frame was lower in the middle but perhaps it's just the seat that gives it the chopped/lower saddle stance? I thought the 2 Seca frames would be closer.
I'm planning to mount an XJ700 rear wheel, I heard somewhere the Turbo has a larger rear brake so perhaps I need to retain the RJ brake plate. Do the RJ and LJ take the same rear brake shoes?

K-moe once I get the cap off the Turbo I'll let you know if there is more vile stuff in there. LOL.

 

Yes........all these bikes use the same rear shoes: XJ650RJ Seca, XJ650 Turbo, XJ650 Police models, all XJ700 models, and all XJ750 models with rear drum brakes.

I believe so. The tank is huge (tall). I think that will be a challenge in trying to fit the RJ seats, tanks, and side covers. My understanding is that you want an XJ650RJ Seca visually, with a turbo drivetrain. That's why I suggest starting with the RJ and swapping the engine into it (bolt in change, basically) and then working on the electrics, etc. to make them compatible with the RJ electrics, cluster, etc. Of course, finding the room for the surge tank, air cleaner, and fuel pump on the RJ frame will take some effort , too............so it may be a "six of one/half-dozen of the other" type of situation in terms of effort involved.

I think you may be correct, Dave will know for sure as I believe he has a bunch of bare frames up there to compare against.

 

There is also a build somewhere on here, already, of someone who built a 650 maxim with a 650 turbo engine. The pipes ran around the frame like spaghetti, but do your forum searches.... you'll find it. It may give you some pointers and direction, too....

 

The 1st thing I noticed in the 2 pics I posted above is the batteries are mounted on opposite sides of the bike. Everything crammed into the cavity under the seat is obviously different and has it's own mounting tabs. As you say 6 of one....1/2 dozen other. Not sure if anyone here has watched the Hackaweek videos on You-tube. He has a series of videos where he fabricates a custom fiberglass gas tank for a 750 Honda Sabre. It's a huge undertaking, probably takes 10 hours just to watch the entire series so he's probably got 100 hours actually into it. Always an option if I have to go there. I could always relocate the fuel pump but not many places to hide on an unfaired bike. Everything will be clear once I tear them all down.

 

They make fuel pumps smaller now. Hint, hint.
Match PSI and flow rate.

 

Just Say No.


Batteries are somewhat easier to re-locate, especially if you use an AGM or similar can mount it flat, or on end, etc.

 

I recall that, too, but didn't he relocate the turbo up to the front of the engine (or add an intercooler) and that's why there was the Medusa pipes everywhere?

 

Here's a thread about frame comparisons from a year ago, or so.....

http://xjbikes.com/forums/threads/1982-xj650-frame-similarities.104088/#post-543876

 

yes I read the Maxim turbo thread. He relocated the turbo to the front, even used a different turbo I think. Many more mods than I'm planning.
I have the article from Cycle World in 91 I think with a brief inset showcasing a Turbo with the RJ seat and tank but with FZ750 fairing so it has been done. It looked like he used instruments from the FJ600.

 

Here's the thread on the turbo'd 650 Maxim for everyone else......

http://xjbikes.com/forums/threads/turbocharged-maxim-650-build.21112/

 

He sort of disappeared after his last post......wonder how it all turned out?

 

Since this Turbo will be a long term project I took the time to build a proper stand to park it on. I have a folding table that raises and lowers with a trolley jack but it's too wide for my present single car garage. One day I'll splurge on one of those commercial lift tables.
Since my last post I've acquired a few more pieces needed from the 650RJ. A guy local to me was converting a mint condition XJ650RJ into a café racer so I bought his instruments, headlight, dash panel, side panels, seat, tail piece, long uncut rear fender (yay!) and tail light and blinkers.
I also bought another gas tank without rust but has a nasty dent in the top which I think I can repair.
Bought a new Chinese reproduction gas cap off eBay.
My local wrecker had an XJ700N rear wheel to match the FZ600 front I'll be using. The spoke pattern does not match but once they're black it's not really noticeable.
The motor has no oil visible in the site glass. I suspect the PO drained it to stop oil from dripping in his garage. Perhaps his issue was just the oil check valve, we shall see.

 

I think he still has it? There is another guy on here, Isaacson. He has a from mounted turbo, although he now has a busa he drags with. He developed a lockout clutch to deal with the added power. I chatted with him a lot, since he and I both use Megasquirt EFI. I had him make a lockout for mine too. He Dynoed The bike at 130 hp @ 15 psi. He did a run at 21 psi and made 141 hp and 93 ft lbs tq! I found it amazing how stout these engines are. I'm getting close, it's been a long build for me. I can't wait to see what my 900 turbo will do. I'll do a dyne pull and then I'm blowing it apart. I'm doing a complete rebuild with forged pistons and custom arp hardware and mls head gasket. I shooting for 175+ hp. He owns E-Fab in Des Monies, talented guy.

http://xjbikes.com/forums/threads/update-on-my-xj650-141whp.59670/#post-450963

 

Speaking on behalf of everyone here, we're all eager to see you complete your project. A monumental undertaking for sure.
Back to my humble plans...I've been watching the classifieds waiting for good pistons and cylinder block from XJ900, XJ750 or XJ700.
I'm considering a larger bore, keeping the same bottom end and head. If I go with the 65mm pistons it would give me a mild boost to 700 cc which I think wouldn't overwhelm the standard 30mm Mikunis.
The stupid YICS passages are what is scaring me away from the 900 block. What I'll need to machine off the block for the 650 stroke will chew too much into the YICS sealing surface.
They could be plugged up I guess.
I'm thinking it would be easiest to go for XJ700 block and shim it higher with extra base gaskets. This is way down the road for me at the moment.
As I stated earlier, 1st thing on the agenda is to get a good running stock XJ650LJ.

 

I actually sold a complete engine (minus carbs) to a guy in hamilton last year for next to nothing. If you still need this, I can try and track down his old email.
I gotta come to Waterloo now to check out your project. I like the original turbo look. If Star-Lord in Guardians rode a bike, that would be it. lol.
Are you using that 4:1 exhaust on the old Seca ? (is it salvageable ?)
About 2-3 months ago a guy posted an'84 XJ750 RL with low kms that needed a new tank. Not much else and he was selling for well under $1000. Would your turbo tank fit ? They look very similar. Cheers

 

Jason I have the 4-1 Mac available if you're interested. The silencer has rust through the chrome only where the mounting tab welds on, chrome good elsewhere. The header pipes will need to be sandblasted and painted. Otherwise very serviceable, $50.
Not sure if the turbo tank fits the 750RL but it was never intended to be mounted without a plastic cover. Not a good candidate.