S1 Publishing(Oxford)© 1999-08

World of motorcycleS
S1 Publishing(Oxford)© 1999-08
Fault Finder
If I ever have a problem with my machines (and I have had plenty of that in my time), I have a regular check list which I run through to determine the location of the fault. It's a good idea to go through this list, or have your own before you start spannering unneccessaraly. In my experience most time spent fixing the bikes is spent on fault finding. 
Bike will not start, but......
 If there is no neutral/oil light showing........
Check main fuse
Check battery terminals
Check Battery condition
Bike will not start, but....
 Neutral/oil shows then dims/fails when start button used
Check run/stop (with someYamahas, pull in the clutch lever)
Check battery terminals
Check battery condition
Check engine to see if seized
Bike will not start, but.....
 The starter motor will not turn over the engine
Check solenoid
Check engine to see if seized
Check starter motor
Bike will not start, but.....
 Starter motor turns over the engine
Check spark
Check spark plug
Check  fuel &/or tap
Check carburetta
Check compression
Unknown Internal Engine Noises
(Knocks rattles & shakes) 
If you here these, you can use a screwdrider blade as a stethoscope (better still use a doctors one) to locate where it's coming from. 

Top end
you can usualy tell if a tappet has worked loose, or a shim has worn, 
To confirm it you'll have to remove the rocker cover
You'll need a feeler guage and manufacturers measurements

Barrels, pistons rings etc
  If a set of rings have just broken they rattle before you get the smoke. 
If you hear any knocking from here then a broken piston or dropped valve (usualy this will seize an engine)
To confirm those, rocker cover and head, if you've got an overhead cam you'll have to know how to re set the valve timing before you remove that.
You'll also need a Torque wrench and manufacturers torque settings

Bottom end
If you hear knocking coming from the bottom end, it's probably your big ends, you'll need to take off the head and barrels to find out for sure. 
check HERE for a bit more info. 
It could also be a worn or broken bearings.
The info is from a single two stroke, but it's the same for a four stroke four as it for a diesl etc.
If it's a grinding noise, check your oil and remove your sump plate if you have one. If you find silver (aliminium) paste in the oil, it's a complete strip to check each component, no easy way! 
You'll need a good toolbox full of stuff, manufacturers setting and plenty time of patience!

This is just a general guide.
If you are about to do your own maintenance, using these pages, I take no responsibility if you get things wrong!
Last updated 23-08-08