tankygsy

Hi guys cheers for all suggestions but still no go. Pardon my terminology regarding eyeballing the woodruff key but I'm on iPhone keyboard. When I said eyeballing I meant I have had the flywheel off completely and checked the woodruff key thouroughly, no sign of slippage. The timing is fixed on these motors with the cdi unit advancing / retarding the spark timing so nothing mechanical there to check really. While doing some resistance tests on the magneto pickup (the readings were good around 96ohms on my meter) I did notice while probing the 2 terminals of the pickup and at the same time turning the flywheel to the spark point that I only had continuity through the puck up for a split second. Is this correct? I would have thought that provided the flywheel was at the correct degree of rotation the pickup would be a closed circuit. What do you guys think?

Ok did some compression tests on my mates motor (using my own gauge, last time my mate dud it as I was out of the island).. His motor read 155psi and mine is 140 psi. My bike should be firing up with this kind of figures. I have fitted my cdi and rectifier unit to his bike and it runs fine. as I said earlier it is sparking well and has plenty of fuel going through. Reeds are good and plug gets wet with fuel while kicking over. going back to look at the timing as per lowbrows comment above and see what I can find.

Hi lowbrow, cheers for that mate. I've eyeballed the woodruff key and it seems all ok no sign of slippage. I'm returning from work today where I have been the last 5 days so will have another cack at it this week during my 5 days off- oh the joys of shift work A Freind of mine has a 280 pro same as mine so I'm going to do a compression test on his motor and compare results, his engine is fairly fresh so should get into the ballpark, just hope his engine still has stock internals.

someone please help, im trying to find out compression figures for a 2007 (or other years) 280cc txt pro gas gas trial bike. Mine refuses to start and i beleive its a low compression issue. Gasgas uk dont have any figures but surely someone would have taken figures - if only for maintenece monitoring! I know an accurate figure is impossible as all motors are different but a ballpart figure to withing 20-30 psi must be possible from someone here. Mine currently is at 120-125 psi. it refuses to start. it has fuel, it has spark but no bang.. Cheers. Glenn