buying an xj

my current 82 xj650 is in need of some repair....but it's my only mode of transport so i can't afford any down time. so i thought i'd buy another one in better working condition and keep my current one as a parts bike or rebuild it. i'm checking out an 83 xj 650 supposedly in great shape and was wondering what an expert would check/test/look at before handing over hard earned cash? seller said he's second owner, bike has 10k miles, tank dipped recently and carb work(i'm not sure what) done as well as "basic maintenance" also, any good questions to ask seller would be helpful. i'm a newbie to working on bikes so if you don't mind break it down barney style. thanks

 

Start with a compression test. "Hear" it run if it will. If not do a serious visual check. Fork seals?? Oil level?? Color of oil?? A good general once over with ideas of cost to fix each..........Buyer beware, but an '83 with 10k would be worth lookin at.

 

Don't go by look, go by feel.... example.... grab the wheels and see if there is play in them, if so the bearings are probably bad.... etc.
I thought mine was in good shape but here is everything I have done to it in the last 3 months (this should give you some ideas on what to look for.....

What has been done on my 1982 XJ550 Maxim:

Rebuilt front forks
Replaced front brake pads
Replaced rear brake shoes
Replaced cut off switch assembly
Adjusted chain tension
Cleaned and lubed chain
Installed in line fuel filter
Replaced stock oil filter with conversion kit for screw on type filter
Changed oil
Replaced headlight bracket with new OEM part
Replaced blinker switch assembly
Added Battery Tender
Installed new glass mat battery
Added Tool Pouch
Adjusted Valves
Replaced Valve cover gasket
Repaired stripped bolts on valve covers
Added windshield
Repaired Tach. cable leak
Replaced grips
Replaced throttle tube
Replaced both tires (new)
Shimmed front brake caliper
Had carbs professionally rebuilt buffed and polished
Synced carbs
Color tuned carbs
Changed plugs
Adjusted Cam chain tension
Replaced brake reservoir gasket and screws
Added new rubber for all footrests and shifter
Installed new rear shocks
Replaced Lic. Plate light fixture and bulb
Replaced front wheel bearings and axle parts
Replaced rear wheel bearings and axle parts
Added sissy bar (new reupholstered backrest pad)
Replaced rear tail light lens and gaskets
Replaced rear blinkers (new)
Cleaned out air box
Changed air filter
Changed gas and vac. Lines
Replaced both side covers
Added new petcock on tank
Rebuilt gas cap
Had both side covers and tank professionally painted
Replaced both rubber seat retainers
Replaced both sets of side cover grommets
Added chrome tank edge trim
Went through and replaced some of the wiring harness
Replaced and repaired many stripped or missing screws and bolts found on bike
Replaced Fuse box

 

Exactly......give it a colonoscopy...LOL

 

some of that is over my head at this point but i'm learning fast. if the bike will start right up is a compression test necessary?

 

Nice old biker dude, but some of that wasn't necessary, lol, just what you wanted (and as a fellow '82 550 owner, I hate you and what you've done with yours, lol!). I definitely agree with the "feel" test, the compression test, (yes, still necessary even if it starts right up) the basic test of do the lights, blinkers, brakes, tires have good tread/date codes, gauges work, etc., and does it ride like something you feel safe and comfortable on? For about 1200 and up, for one of these bikes, you shouldn't have to do hardly anything for it to be "turn-key." Like most people on here, I don't believe half the shite that the po said at this point, for good reason, but it's all about being safe and having a fun and more importantly, having a dependable bike to ride. Good luck to you!

Mac

 

Also ask when was:
Last valve shim check - ask if it was done and ask if they still have the numbers
Last oil/filter change
last air filter replacement
Ever laid down - look for dents in mufflers and broken fins on motor
Steering head - bike on center stand, sit on back of seat to raise front wheel, check for any flat spots and make sure the bars "fall" to the left or right
Tire date code
Front brake hose date

 

Compression test is definitely needed. If the current owner declines your request to perform one...walk away.

 

+1. Bring your gauge, a battery and a spark plug wrench. And don't forget to unplug the TCI.

 

thanks...this is all very helpful. i'm going to buy a compression gauge today but being a newbie i'm not sure how to test it. pull a plug, screw the gauge in...that's about all i know. so, what is the step by step procedure for doing a compression test? and what numbers should i be hoping for? thanks again guys...this info is priceless.

 

If the bike runs, get it warmed up a bit. Put the battery on a trickle charger or make sure it is charged good. Need a really good spin on the starter as slower turning pistons net lower than reality compression numbers. Disconnect the plug wires from the plugs and maybe remove all the plugs). Screw in the gauge (harbor freight has a decent one for $20 or so). Hold the throttle wide open and hit the starter. Let it get 4-5 good revolutions (pulsings of the gauge) and write down the result.

Rinse and repeat.

When done, you should have numbers north of 120 for each hole. And all of those should be relatively close to each other in numbers.

EDIT: Do what Fitz said and disconnect the TCI. This stops spark from happening and potentially damaging the TCI.

 

do i pull all the plugs first and then check each or do i only pull one plug at a time, testing and replacing each before i move to the next one?
blake

 

Pull all the plugs.
Unplug the tci.
Put a battery charger on if you can.
Hold throttle wide open.
Spin over 4-5 revolutions per cylinder ( the gauge will quit climbing).
What you are looking for is that they are close to the same for all cylinders ( +/- 10%).
DO give the starter time to cool between tests.
If the numbers are low squirt a small amount of engine oil into the cylinder (1/2 teaspoon is plenty). Get the owner's permission first!
If the numbers come up a bunch the compression rings are worn.
If the numbers DON'T come up a bunch the valves are not sealing well.
Typical numbers are in the 120 to 150 psi range for most engines that run on regular fuel ( like our engines).

Chances are good that if well maintained the numbers will be fine.