I thought I would share a few tips to consider when buying bikes in general.
Tip 1: First thing I do (preferable with cold exhaust!) is rub my finger inside the exhaust pipe. If you end up with a very sooty finger this means that the bike is running rich (which increases cylinder wear) but is nothing to worry about immediately as it is can be as simple as mixture adjustment or airfilter replacement (cheap).
If on the other hand you finger is covered in black oil then the problem is something to take seriously. As this indicates either worn rings/cylinder bore or valve stem oil seals.
Fixing either necessitates a head removal.
But as the repair cost can differ considerably, this next check will help you decide if you want to continue..
Start the bike and look for blue smoke from the exhaust.
If the problem is valve stem oil seals the oil will burn off and smoke will stop within a few minutes of starting and only reappear after the bike has been stopped and restarted after some hours.
If the smoke doesnt stop within a few minutes, and in fact probably increases with revs/load it is a costly repair.. Rebore, New rings and potentially more.
Tip 2:
Check for steering head/bearing wear (cheap fix, but good to knock the price down).
Sit on the bike and hold the front brake on tight, now rock the bike forward and back. Listen for any clunking noise from the headstock area and look for any movement there too.
Tip 3:
Check swingarm bushing and rear wheel bearing wear (another cheapish fix if you can do it yourself in particular).
This one is easier if the bike has a centre/main stand and you can raise the rear wheel off the ground.
Get someone to steady the bike while you try rock the back wheel left to right. Look for any movement at the swingarm pivot bolt area. (If indeed you feel any side to side movement the bushings are shot and/or the wheel bearing is in need of replacement.
Tip 4:
Cam chain. Excessive noise indicates need for adjustment or wear in the chain or tensioner.
If you rev the bike and then quickly shut of the throttle this can help exagerate any existing chain noise. Just do short throttle blips (no need to rev real high or anything). The noise will be most obvious when you close the throttle and before the engine returns to idle RPM.
Tip 5:
Disc wear. (MAKE SURE THE BIKE IS COLD OR THIS CHECK Will result in serious finger burns). To check this simply place you finger and thumb on the disc/rotor and rub back and forth. What you are looking for is the ridges in the disc surface which indicate that the bike has been ridden with the pads worn down, as when the metal of the pad rub on the disk the scoring/ridges occur. Alternately it could indicate that incorrect (coarse/sintered) pads have been used. (But indeed high mileage causes some ridges naturally)
Tip 6:
Look for a blown or leaking head gasket.
Look for oil seeping from between the head and barrels. (Not cheap for a novice to fix). This will be more evident after a longer ride.
Also look at the condition of the oil. Remove the dip stick and look for any white/grey crud.
Note; a blown head gasket that isnt replaced can lead to much more serious problems, as air is sucked in and screws with your mixture which can result in a very hot engine and holed piston.
Tip 7:
Wheel misalignment, bent forks, bent frame (expensive..walk away if you are a novice) This can be real difficult to spot with your eye. Straighten the bars and walk 5 or so metres from the front and then rear of the bike. Look for any obvious misalignment.
Bent bars can sometimes make you think the forks are bent, but if in doubt its not worth the risk.
What I do is take the bike for a test spin. when riding in a straight line are the bars straight? Does the bike corner without wobbles in both right and left corners? Best if you can find a smooth road with some long bends (the type you can cruise round at 70klms + )). Short abrupt corners dont show the problem up as well.
Tip 8:
Gearbox. Does the bike freely go into each gear without false neturals? Is there any whine noises in any particular gear? Smooth roads are best for this assessment.
If you are an experienced rider you may want to try rapid acceleration in first and second gear. As in my experience these are the more likely gears to have problems (due previous fast gettaways at the lights and subsequent miss-selection/crunches). If the bike jumps out of gear then walk away.. not cheap or easy.)
Tip 9:
Has the bike been dropped or had minor collision?
Check the ends of the clutch and brake levers for scoring. Check the ends of indicators and mirrors (cheap, to fix if you are fussy, but this is a good one for negiotation). If you do find scoring on any of the levers then I suggest you check the engine casings for cracks/leaks on that side.
Tip 10:
Fork tube Pitting and Fork seals. Depress the forks and look for oil on the tubes. The seals are very cheap to buy but if you are a novice and will need a repair place to do the work they may be a little expensive (couple of hours work). If the forks have rust pitting the seals will soon go..
Tip 11:
Look at the wheel rims for kerb dents. Chrome flaking and rust can indicate an area to be particularly suspicious of. Look for broken or loose spokes.
Tip 12:
Electric system and charging.
Check all lights and indicators (trivial). Now with the headlight on start the bike and rev it, then let it idol. Is there a significant dimming or brightening of the light?. (This can indicate a faulty regulator/rectifier/generator or a simple battery problem). But the best way to test this is with a volt meter accross the battery terminals. With the bike running and lights on I think the volts should be around 12.5-14.5 volts. Preferably above 13. (Not 11 and NOT 15 ++) high voltage here would indicate a faulty reg/rectifier (cheap secondhand and easy). [I have had coils melt like candles with a faulty regulator and a GS550 that was charging 16volts..]
I could go on..but shouldnt.
Truth be told the best thing you can do is bring an experienced friend with you.
As no matter how experienced you are yourself once you see the bike...you forget most things and just want to hand the cash over and ride away into the sunset!!
Hope these tips help!
Ride safe.
G.
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