Hi, recently my Yamaha RD125 MK2 hasn't been starting up properly from cold or even when its warm and today i cant get it started at all. I cleaned the carb up and still get nothing. I tried kickstarting it whilst my finger was over the spark plug hole and it did not force my finger off so im guessing the compression is low? Ive also tried new spark plugs and fresh fuel but still nothing.
Does anyone know what i can do to make it start? This has only started happening recently and im guessing it might be piston rings or head gasket maybe?
2007-07-09 10:19:57 · 5 answers · asked by Anonymous in Cars & Transportation ➔ Motorcycles
always start from the basics first....check you have a spark at the plug and that its occurring at the right time i.e just before tdc.....then check you are actually getting fuel thro to the cylinder not just to the carb..can try some easistart or similar into the airintake ...note that compression on a 2 stroke is much less than that on a 4 stroke so your method of checking compression may not valid..I would still expect a bike to try and start even with poor compression if all the other things like fuel and ignition are correct...good luck
2007-07-09 10:48:59 · answer #1 · answered by cosso77 3 · 1⤊ 0⤋
Sounds like no fuel getting to the spark plug. Is it wet with gas? If no take the carb screws turn them in, until they stop. (Count the1/2 turns) spray carb cleaner in the jet port. usually there are 2. Return to their position and try and start the bike.
It is possible you may have to pull the float bowl and clean the old gas and varnish from it. Good luck!
2007-07-13 02:13:43 · answer #2 · answered by Lamont 2 · 0⤊ 0⤋
You figured out the problem yourself.
Low compression.
Re-check it with a compression guage.
OR
Remove the exhaust pipe and look in the exhaust port with a flash light & mirror.
If you see any scoring of the piston and cylinder wall, or dis-coloration below the rings, the top end will need repair (cylinder bore, piston & rings).
2007-07-09 19:35:40 · answer #3 · answered by guardrailjim 7 · 1⤊ 0⤋
cosso has it right... check spark... check fuel in the cylinder.. check timing.. then look elsewhere...
if your not sure what your doing ,,go hear.. tells you how to get it working.. lots of good info
http://www.dansmc.com/MC_repaircourse.htm
just had another thought.. two strokes (reed inducted) draw the fuel into the crank case before its fed into the cylinder.. so a leak in the crank case can make them hard to start.. ( the leak could be in the case gaskets, or the seals on the crankshaft, big job to pull apart & repair..so I hope its something simpler)
2007-07-09 19:17:18 · answer #4 · answered by Anonymous · 0⤊ 0⤋
another problem is the complete set of wiring system if ur bike is too old.
2007-07-09 17:37:47 · answer #5 · answered by LOSTIT 1 · 0⤊ 2⤋