My 2004 250 Rev3 used to start on the first or second kick. I since rode it back in November and it took 7 or 8 kicks to get it going from cold. I didn't think much of it at the time, but when I came to ride it in early Jan, it wouldn't start. Changed the spark plug and it started. Then, tried to fire it up last weekend and it would not start at all: changed plug, drained float bowl, blew out jets... nothing.

Plug sparks when I kicj it over with the plug out. Any suggestions on what else to look at?

try a spot of petrol down the bore if it fires up you will know its fuel related .if it fires up let it run for a while then give it a good roasting along the road it gives it a clean out and gets it up to temp

Gday, it needs fresh fuel before you do anything else. Drain the old stuff completely and go from there.

Cheers,

Stork.

The guys are right.

Its a classic basics thing. If you haven't altered anything (carb, ignition timing,or anything else major) then:-

Fuel, good fuel? unleaded can deteriorate in months.

Buy a can of easy-start and spray down the carb before kicking, this is so volatile that it will enable a start under very poor conditions.

Can you smell strong fuel from exhaust when youve kicked it over a few times on choke? If not, check fuel supply, and progress to the carb.

Ignition, sparking with the plug out?, clean, dry plug?

Test the plug on something else (lawnmower, another bike), plugs can break down under compression.

Compression, usual resistance under kicking?

Try a compression tester and make sure its above 100PSI (most engines will start with a minimum of 100PSI).

with these 3 basics the majority of engines will start and run badly even with minor faults (broken reeds, worn rings, crank seals gone, poor ignition timing etc.)

Dom

I know there are very few wires on a trials bike, but whip the tank cover off and check all the connections you can. Again, costs nothing but a bit of time, and eliminates a loose wire. (on a road bike I fitted a lead to trickle charge the battery and the terminal bolt was not done up properly and caused a very peculiar and irregular miss fire and occasional non start).

check the rubber connectors on the carb -to airbox and to engine- are seated fine and not perished.

I had an MX bike that was a bugger to start (250 2T), but once warm was fine all day - I put that down to a worn barrel and cracked shoulder on the piston when I pulled it apart and sorted it.