i have recently pourchased a 2004 280 pro which takes 5 or 6 kicks to start when hot. i have received the following advice which is leaving me confused. one advisor says reduce float height to 17.5mm and reduce air gap at sesor to flywheel to a minimum while another advisor says replace the 35 pilot jet with a 38 but not to reduce the aforementioned gap as the spark will not be improved by doing so as the cdi unit produces the spark and the pick up is only a trigger. any help would be appreciated

Try putting it in neutral,sometimes the clutch drags slightly which stops it spinning over as quickly as it needs to to get a good spark.If the previous owner has used the wrong gear oil it can swell the fibre plates causing the drag .Does it start well from cold,and run well when warm,if so I doubt any carburation/ignition problems.

Before you do all that replace the starter jet in the carb its not giving you enough fuel. When you take apart the carb there is a long jet sticking out with an o-ring on the bottom of it, thats your starter jet. You need a bigger one. I had a bike for 2 years and fought with this problem, replaced it before I sold it and it fixed it. Made me made just a little.

the starter jet in the carb its not giving you enough fuel.

Gtgasgas, the bike is already hot, so the starterjet is not in the picture.

To have a feel for the problem, you must tell how the bike is starting when cold, with or without choke, how it runs when cold and warm etc. How is yr plug.....what heat range...?

All this info must lead to a solution. Normally a 2stroke, when hot, must start with a one healthy kick.

When not, mostly it was already running lean/rich etc in the first place.

the bike runs with a slight bit of 4 strokeing and an occasional knockwhich has been improved by using a high octane fuel.

can someone confirm that the starter jet only affects cold starts or does it affect hot starting as well?

the bike runs with a slight bit of 4 strokeing and an occasional knockwhich has been improved by using a high octane fuel.

can someone confirm that the starter jet only affects cold starts or does it affect hot starting as well?

Sounds lean on the pilot, but you can also try this that helps restarting my 280 after a tipover or stall.

Just kick the engine over once or twice a little slower than normal to help ' clear its throat '. The same thing works for a 4 stroke thats vapor locked. Seeing as it sounds lean, it could be vapor locking.

To help with cold starting too, I put the bike in second (no choke) and sit on it so you can get enough traction and rock it forward/back a couple times. Click on the choke and mine fires up on the 1st or 2nd kick when cold and 1st when hot.

Steam ,GasGas has a very good point. Start from the beginning did you buy the bike from someone in your area, look at your plug is it grey or oily. You might start with some jetting changes. But first thing is look at your plug.

would like to try larger starter jet. any suggestions what size and where to get one from. gas gas uk do not have larger than a 60(standard). i have tried a 65 but no noticeable difference