Turbocharging my 82 XJ650 Maxim

Ok so heres the deal guys. I have an 82 Maxim 650 with a little over 6,000 miles and in near perfect condition other than a small dent in the tank. I love the bike but it could certainly use more power. So today I found an 82 Seca turbo 650 and bought it. It has 12,000 miles, new tires, a power up kit, and is in damn good condition for the year. It has minor surface rust on the exhaust and the shocks but nothing major. It supposedly ran when parked but I dont know how long ago thats been. It is complete other than lower side fairings, title, and keys. So I figure what the hay I might as well make my little maxim have some boost. I have searched and searched but so far I havent found anyone who has done the swap as of yet. I plan on hotwiring the bike and getting it to run decently and then swapping all of the parts over. I intend on using the harness and all of the electronics from the seca on my maxim although the ugly instrument panel has to go. I hate that thing with a passion. I am going to install the entire front fork and triple tree assy on the maxim along with the rear rim, swingarm, and shocks. What I am wondering is what mods would be good while I have everything apart? I have a nice triumph exhaust can that would look nice on the bike and I have heard of several people removing the right side pipe altogether. Does anyone know anything about doing that? At the moment I dont know if I am going to keep the stock turbo or upgrade it to the 9a or whatever it is. I plan on putting on an aftermarket air filter and probably a small intercooler but aside from that I want the bike to appear mostly stock-ish. I intend on installing a tank from an xj750 for the added fuel capacity, either some flat bars or clip ons, and a small cafe racer style fairing. I have read about doing an xj900 top end swap but I dont really think I want to tackle that right now. I intend on starting the project this week and once I figure out how to post pics I will have some up for everyone to see.

 

You officially got the easy part done!

That would be: "Telling us about it!"

Now comes the sweat and blood. Some of the adventure is going to go smooth as silk. The landmines are the same for everybody.

Soft steel Cap Screws on Cylinder Head Manifolds that tend to break.
Soft steel Studs with rusted-on Nuts on the Exhaust Collars that tend to break.
Exhaust system hardware not moved an inch in 25 years that strip and break.
Pipes that won't want to come out of the collector and need a fight.

Other than that, Mrs. Kennedy, how'd you like your visit to Dallas?

Do pix all the way.
Everybody is going to be interested in this project!

Good Luck!
Oz fishally givvin yuh boaf tums aup!
Gits yer Mo-Jo woikin' ann build you a bike!
Wheeze all behine yuh tuh gidd-id-own!

 

Can anyone shed some light on these sorry pieces of engineering known as a pressurized petcock and carbs. Are most of the internals like normal mikuni bs series or are they all ascrew inside?

 

They are like Mikini's. The Jets are different and the Air Jets are placed in another location.

The operation and theory remains the same.
But, the Mikuni Air Jets are on the Intake Horn rather than under the Rubber Diaphragm.

 

Maybe this will help:

 

i would love to turbo my 1100, anybody know if those engines can handle boost?

 

So today i tore the turbo bike all apart. Believe it or not all of the exhaust bolts came out without any problems. Im going to paint the engine and then throw it in the maxim as it is. It only has 12,000 miles and pulling it out isnt that big of a deal so I'll risk it. The turbo has a little side play but itll have to work for right now. If I blow it up it will just be a reason to upgrade. The carbs are varnished to oblivion right now so they are going to need some attention. Hopefully they wont need too much. I am going to flush the fuel pump out really good and hope for the best as it looks like finding another one will be a pain in the butt. The petcock is screwed. Can anyone point me in the right direction for a rebuild kit for it? I hope they still make them. Aside from that I have a lot of painting and turd polishing to do. I intend on using the seca turbo harness with the maxim handlebar controls and guages so I may have some wiring to fiddle with. From the looks of it I am just going to throw the turbo front fork assy in as a unit and get around to rebuilding and strengthening it later. I think the bike will be a good deal lighter without all of the plastic fairing crap so maybe it wont handle so bad. Now all I need is a bunch of time, a xj750 gas tank, petcock rebuild kit, and a bunch of carb cleaner and hoses. I cant wait till I get the old girl together and have it screaming at 9000 rpm at 15lbs of boost.

 

The turbo fuel tanks are vented differently than all other XJ tanks, probably for reasons that have to do with the fuel system.......

 

Yeah I think I will have to seal the gas cap very well cause l think the boost pressurizes the tank.

 

The tank absolutely does not become pressurized, it vents like any other. The only thing that goes to it is the return fuel from the pressure regulator.

I admire your work ethic, but I think changing the cosmetics on the turbo to suit your tastes would be a whole hell of a lot easier than doing a transplant to your maxim.

As for turbocharging an 1100....

Nothing Exceeds Like XS

 

Un-freakin'-real!
What a MONSTER!

Nice work and craftsmanship all over that bike.
It looks like they come that way!

Beautiful ride. Magnificent is a better word.
I'm blown away buy the looks of the thing!

My hats off to you, 'Mate!

 

Well I'm glad the tank is not pressurized. As far as doing the swap, it shouldnt be that bad. I've done more challenging swaps and I have the means to fabricate about anything. Also the seca didnt have a title and my maxim has a clear title and has a huge amount of sentimental value as it was my late grandfathers bike. Plus I think it would be really cool to have a turboed maxim. I hate the way the seca turbo looks. My dream would be my 650 sitting on spokes with flat bars, a nice gloss black paint job on the tank and fenders, a nice stainless exhaust, and lots and lots of boost.

 

http://www.motad.co.uk/product.php?prod ... ete+System

Stainless

 

I like the looks of that system. Too bad they dont make aftermarket pipes for the turbo bikes. I have a nice triumph can that I think will work with some mods. Hey you dont know where I can get a petcock rebuild kit do u? All I can find is a new oem petcock for $115. Which I'm tempted to buy but I dont really need the whole darn thing

 

talk to chacal... the man should be able to find you something that'll work

 

I would love to see more pics of that XS11. I like the stock tank.

 

After letting my bike sit for months on end in many pieces I have got the motivation to work on it some more.

Today I installed the seca turbo front end with the dual slotted discs. Looks much much better. I plan on buying some ss braided brake lines and Im sure the 26 year old rubber lines arent very good at all.

I am keeping my stock front fender which bolted to the new forks just fine but it is at a crazy angle....like 3 inches clearance on the front and like 2cm clearance at the rear. Thats not gonna work.

I started to make the mounting holes larger so I can correct the angle but my crappy rechargeable drill died. Its charging now so it will be ready in the morning.

I took the bowls off the turbo carbs and believe it or not they arent too bad. Not nearly as bad as I suspected. I am going to tear them down completely tomorrow and clean them thoroughly.

I still need a petcock kit and oring but I have a whole bunch more work ahead of me to worry about that right now.

Tomorrow I plan on getting the carbs straightened out, removing the centerstand mounts, installing the turbo mount & maybe the centerstand mounts from the seca turbo, and swapping out the rear wheel and brakes.

I should have current pics tomorrow. The little maxim sure is looking meaner with the wider front tire and dual discs from the seca. Im sure it will look even better when I get the rear wheel swapped over.

I'm trying to make the bike look as stock as possible so the little kids on their 600's will really get embarrassed as the "grandpa" bike comes flying by them.

 

Love to get my hands on that swingarm!

 

turbos on cars TAKE A SEPERATE LARGE OIL LINE TO LUBE THEM... how does your turbo get OIL TO IT ? can you add that to your engine from the old one ???????????????????????????

 

That's why I am using the xj650lj turbo Seca engine. It has the oil feed line and return line fittings on the lower crankcase. No other xj engines have the provisions for turbo oil lines. I am sure you could rig one up fairly easily by tapping into the oil supply going to the head but you'd be better off just getting the turbo motor as it has lower compression and much stronger internals.

 

Just got the turbo back from the shop. Cleaned, rebuilt, balanced, and ready to go. I plan on getting some polishing discs and making the little turbo shine.

I am collecting more parts for the fuel injection every day. Last weekend I grabbed a Venom fuel rail with injectors from a cavalier for $20. I checked and the spacing a little bit larger but it is usable none the less.

I have a WHOLE bunch more stuff to do the bike before it is ready to hit the road. I am debating on whether or not to stretch the swingarm 6 inches or so. I am also on the hunt for xj900 cylinders and pistons to drop in the bike while I have it in 1,000,000 pieces.

I am trying to have it 100% completed around feb or march...but I am sure many things will be swapped out before then.

 

If you lengthen the swingarm won't cornering ability turn to crap? Just curious.

 

I intend on reinforcing the swingarm and the frame so it should flex much less than stock. With the swapped out front end and other mods it should handle decently.

 

I have been pretty bored this weekend so I decided I would start working on the aesthetics part of my turbo. So far I have about 4 hours invested in it and im not anywhere near being done. I am in the process of removing what isnt needed on the turbo housing and sanding & polishing the housing to a chrome like finish.



Hopefully I will have time tomorrow to remove the rest of the un needed stuff and start sanding the housing. The end product should be well work the wait. Just compare the pic with the stock turbo to this pic and you should be pleasantly surprized by the progress

 

WOW what an inspiration. great colors. how much you want for it lol

 

Had today off so I spent another hour and a half or so on the compressor housing.

I still have more sanding and then a whole lot of polishing ahead of me but I like the progress so far. And for those wondering why the heck I am spending 8-10 hours on a piece of the bike that wont even be visable unless I either lay it over or someone gets on their hands and knees.. I dont know I am just wierd I guess.

 

Got some more progress on the compressor housing. Ive been spending more time at work, so my projects come to a standstill. I still have some more to be done on the center of the housing, but I got tired of working on it today. I did a 5 minute polish job with some mothers chrome polish and an old sock...I was very surprized at the outcome. I can only imagine how good its gonna look after I spend time and actually use a real polishing compound. The whole aluminum polishing thing is kind of addicting. Now I want to do my handlebar controls, and my upper triple tree, then my wheels, and forks, and valve cover, and engine sidecovers, hell screw it I might as well do the engine cases too while I'm at it.

 

*delete*

 

From your first post i noticed you said you wanted a xj750 tank on your xj650, i ran into a problem with that and put it on hold, the triple tree connected with the left of the tank, it seems the stops for the forks (part of frame) were not forward enuff for the 750 tank so moding the stops is a future project for me, maybe weld maybe drill and and a bolt into the stops...dunno yet, gunna stip the bike and have the frame soda blasted and powder coated soon! ill do the mod then. sorry i got no info on the turbo itself.

 

it's been a few years but have you had any luck with the swap?

 

Very curious what happened of this project as I just picked up a seca and planned on doing the same thing, decided to look for possible build threads

 

buy a 650 turbo save your self a lot of headache
there are other threads on this subject. the turbo motor is built different to take the stress of the turbo as well as different type of carbs
stronger parts needed or you may blow the standard 650 motor.

original poster said

 

It's not a matter of may blow, but will blow. If you want anything other than a tiny amount of boost, you have to use the Turbo engine.

 

I was hoping to use the 650 maxim engine.. 9.2:1 compression vs the 8.2:1 seca turbo compression. Also the maxim has bigger carbs and the stroke is the same from both engines. I've always wanted to mix the two together.
Looking at the specs in comparison there is almost no difference in 1/4 mile. Just wanted the xj650 to have the oompf from the seca... If I recall the Seca has the forged pistons and there is a difference in the piston crowns. It's doable.. if one has time to tinker

http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj650_turbo.htm
http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj650_maxim.htm

 

The turbo Seca also has stronger engine cases.

If all a person wants is more "oomph" the fast route is to swap in an xj750 or XJ900 engine.

Putting a turbo on the non-turbo engines has been done, but it's a dance between getting a bit more "oomph" and breaking the engine. The turbo engine is the better platform to work from, and has much more potential than Yamaha ever got out of it.

 

The comment got deleted??

 

Not by any moderator.

 

Maxim carbs won't work. Turbo Seca carbs are pressurized, i.e. the "atmosphere" side of the slide diaphragm is actually at compressor pressure, and the fuel is pumped in at 2 psi above the compressor pressure, or the bowls would never fill.

The Turbo had an 8.2:1 compression ratio for a reason, all that extra fuel/air at higher pressure/temperature will detonate. Furthermore, the TCI can sense detonation using a mic and retard timing to minimize it.

So if you don't want to use the entire Turbo Seca plant, you will at a minimum need to fuel inject the bike and make your own fuel/timing maps to handle the different operating conditions. You aren't the first one to ask about the project and there's a reason why the answer is always the same: "Start with a Turbo Seca."

I've seen one user put all his maxim parts on a Turbo Seca plant and it looked awesome. I have a turbo seca that I restored from the frame up and can promise you that it isn't just the turbocharger that is needed.

Like K-Moe said, if you want more oomph, "there's no replacement for displacement." That's what the big-4 concluded. If you want a turbo for the "cool factor" get a Turbo Seca and modify from there. If you want to start from scratch for the experience, I'd probably pick a better plant that is already fuel injected

 

I hear ya, but I would still like to humor this idea for a bit if anyone else is up for it. After thinking a bit more about it, what if one were to build a "box" around the carbs to equalize the pressure?

 

I'll humor you just to help you realize that my qualification is already well thought out:

You need a small pressure differential between your fuel inlet and you compressor pressure for the bowl of the carb to fill and your venturi to draw up fuel. If your venturi drops the pressure by 2 psi, but your compressor boosts it by 4 psi, there will be 2 psi of pressure forcing fuel back into the tank and nothing will get forced into the airstream.

Therefore you NEED a fuel pump, and a way to regulate the pressure, even if you build a "box" around the carb to pressurize the venturi (i.e. get the slide to act right).

The carb jets and needle will need to be changed for the different performance under boost.

If you start with fuel injection, you avoid all the carb issues,

Now you also need a TCI box that handles the rpm/timing AND boost pressure as an input (from a boost sensor), and perhaps a mic to detect detonation (because carbs won't be very precise in fuel delivery) for some closed-loop feedback.

Add the intake and exhaust plumbing (yamaha picked the rear of the engine for some benefits/tradeoffs), oil line and pump fittings to feed the turbo.

And you still have to worry about blowing up the engine.

 

wouldn't NOS be just as much fun

 

maybe a cam swap would give you the extra ompf you are looking for

from info overload
SOME TANTALIZING THOUGHTS: although we have not----and do not know of anyone who has---there may be opportunities for performance gains via cam-swapping between different models. Here is what we can say with surety:

b) all XJ650 (except, perhaps, for the Turbo models), XJ700 non-X, and XJ750 model cams will interchange. Here's the lift variances between them:

Intake:

* 650 models (except Turbo): 8.50mm
* 700 non-X models: 8.80mm
* 1981-83 750 models: 8.80mm
* 1984 XJ750RL models: 8.80mm

Exhaust:

* 650 models (except Turbo): 7.80mm
* 700 non-X models: 8.30mm
* 1981-83 750 models: 7.80mm
* 1984 XJ750RL models: 8.30mm


Since the cam lift durations and overlap specifications are not available for all models, we can only (for now) guess what those differences are; however, it would be reasonable to speculate that the 700 non-X and XJ750RL cams are the "hottest" of the bunch, followed by the 1981-83 750 cams, and lowest on the totem pole would be the 650 non-Turbo cams.

Although camshaft design and swapping is a real black art, as not only are lift, durations, and overlap issues involved, there's also cam-timing considerations as well as the interaction between all those factors and cylinder size, air flow into and out of the cylinders, etc. to account for.

Please note that in order to correct (or enhance) other design parameters or issues, it is sometimes best to swap out ONLY the intake OR the exhaust cam (rather than both)......so much depends on the engine and bike in question, the intended usage, rpm power range desired, etc.

Like we said, a black art....... Remember, "hotness" in camshafts, just like beauty, is in the eye of the beholder, and it depends on whether your definition of "hot" is "low-end power", "all-around power", "high-end screamer", or some other variation of the above.

If anyone has any experience with cam swaps on these engines, please let us know what you did, and how it worked out!!

d) XJ900RK and RL cams----these we just don't know about. We BELIEVE (but cannot assure you) that they will interchange with all XJ650, XJ700 non-X, and XJ750 engines. If so, they are probably the "hottest" cams available.

 

Never doubted your qualifications, just looking for answers to the "what if" questions I have . Much rather understand a reason as to why not, then just blatantly accept a reason. Only real carb experience I have is from single carb small engines.

Thank you for your response, time to chew this over

 

Manbot is giving you some good info. I watched him go through his build and he's a pretty sharp guy. A lot of folks don't realize everything Yammy did to build the turbo AND make it reliable. The differences, some have been noted included stronger pistons, rods, heads, lower initial compression to help fight soaring heat which in turn presents you with massive detonation, both a sound type detonation sensor mounted at the front of the engine as well as a pneumatic/electric boost sensor off the surge tank(that MUST be checked for correct output on any used unit & corrected) that were wired to the ECM which uses code to interpret the info and demand raising or lowering of the timing. I spoke with factory guys who told me that Yammy did the Destructive testing at 22PSI yet only signed off on a max of 14 (with their stupid turbo-stall inducing "powerup kit") for the general public.

Any BS carbs (Yammy 650 Turbo specific) that you find today will require a complete and I do mean complete rebuild including shaft seals etc. to prevent leakage. I've done dozens and dozens of set and individual carbs and the rebuild of my set took approx 4 hours since they all have to be separated which means removing the butterflies. Then upon completion, you'll need to Red locktite the butterfly screws and deform the ends to prevent the ingestion of any loos screws....probably wouldn't be a good thing for you engine.

I like the carbs because to me, it's simple. I restored mine 6-7 years ago and it still runs like a champ but I'm sure that there are other ways such as FI to skin that cat too.

FWIW: I run 18PSI using a boost controller so I installed a R6 ('99-'02) pump in place of the stock pump. It makes something like 42PSI so it's comfortably higher than my boost pressure.

I just wanted to pass off some info that might make your build easier or more successful.....so good luck!!

jeff

 

The rarity of that bike... if i could get my hands on one I'd probably sell all 5 of my xj650's and my cars