what kind of xj is this?

its got a replacement vin so i cant tell.

i think its an 82 maxim.
but 650 or 750?
and the motor has a stamp on it that makes me think it might be a 750. its my first bike. i picked it up for 500 bucks. the bike starts but only fires on 3 cylinders. i put in new plugs and have begun to rebuild the carbs. (ive never messed with an engibe before but so far, so good) they were really dirty. i have started to paint and polish as i wait for parts to arrive. the tank is in the driveway waiting for the bondo to cure. nothing like rough sanding at midnight.






oh and thanks for having such a badass forum.

 

Welcome, that will be a great project.
The red line on the rear brake hub has given me an idea. Thanks Wiz.

 

Any pics of the tank?

 

2500 cm3 = 2.5 litre. what's that all about?

 

could it be fluid (oil) capacity?

 

check right rear of engine and steering head pipe for a number , should be 3 digits-6digits, get the 3 digits and then look them up here:
http://www.merrittmotorcyclesalvage.com ... lcodes.htm
lists lots (missing my bike though) but may help.

A.B.Ames

edited: actually can see the #'s but not read them in your last photo, flat area just above where you took the pick of the 2500cm3 stamp

 

whoa crap. 5g2-002225. looks like its a 750 and not a 650. 8O ok. thats a ton of info. no wonder my friend said the bike felt really quick.. GUess i picked a big one for a first bike... hehehehe cool!

 

Yes.

 

The shocks,headlight,and rear grab bar are from an XJ 750 Maxim. The body sidecovers,muffler hangers,mufflers,and footpeg setup tell me that the frame is that of a 650 Maxim.

 

Looks like a 650 to me, 650 seat, 650 side cover. 650 speedo Correct for 82. (83 570 uses same speedo though) Would not be 81 since has YICS covers on engine. So my bet is a 650.
Would be cool if it had a 750 engine on 650 frame. Not sure if it would fit but it would be a fun ride with the smaller lighter frame

 

Single front brake = 650
Now let's look at the motor between the pipes #2 and #3 and see if it says "649 CC " cast in the aluminum, or "749 CC", or maybe 748?
it's pretty small, but it should be there,
or if your carbs are opened up, are your main jets "110" or "120"
That's a dead give-away for engine size.

We could also measure your cam lift. . .

Check your compression on your "dead" cylinder.

 

Re:

Its a FRANKENSTIEN bike. 8O

 

Hi,
I found another site that says 5G2 was used for both 650 ('81) & 750 (81-82's) seca's (guess motor's from another).
http://www.dropbears.com/m/models/yamaha/xj67info.htm
So TIMEtoRIDE's advice is best..sorry bout that.
A.B.Ames

 

the engine is a 750. it has the stamp that says 748 on it between #2and#3. thanks to timetoride for that one. I guess thats like 15% for free or something.

The seat doesnt fit quite right. i think its off of a different year frame. the front fits fine but the back latch doesnt have anything to grab on to.

FWIW the headlamp and handlebars are aftermarket. I think the headlamp is some sort of off road enclosure that just happens to fit. Ill post pics of the tank tonight. i just filled in the badge holders with bondo for a smooth look. Ill shoot primer tonight.

 

Do the 650's and 750's both have the same oil capacity??
My 750 SECA has the same 2500cm3.

 

ouch miss post not sure how to delete it?

 

Not from what i found,
My bike (84 XJ750), according to specs is 2.5L oil change and 2.8l with filter replacement (and it's stamped same as yours on case).
650's Info I found say some are 2.65L and some 2.35L (without filter changed) depending on version (i.e 650RJ = 2.65L etc.)

 

my bike is a 650 & the stamp is 2200cm3.
engine / transmission oil quants-oil change only.
xj650-11n (uk) & xj650RJ =2.65 litre, all other xj650 models = 2.35 litre.
all xj750 models = 2.5 ltre.

 

That is because it has the wrong grabrail .The 650 Maxim has a lock mounted on the middle right side of the grab rail. I'll discuss in more detail,check your PM.

 

Interesting, my 83' 650 seems to have an 84' 650 motor 5N9-XXXXXX and has 2500 cm3