Xmax 300 2022 wierd starting issue

[Blendxmax300]

It is my xmax 300 2022

When parked all day in a hill it has problems starting, engine just cranks but when left in flat surfaces engine starts no problem When parked after i struggle starting it gives this problem 2 more times even on flat terrain then it doesnt happen again but the next day when parked again same problems
The bike stays all day in the sun

Bike when turned on it works perfectly I even had a 130km short trip for fun an never gave me a problem starting

I have new battery

New spark plug

Air Filters all changed

Bike has 13.000 km or 8000miles

Can someone help me with my problem

[Andym]

Tilt sensor or fuel breather?

Can you park it facing the other way? Does it make any difference if the tank is full or empty?

Andy

[Blendxmax300]

I didnt try tu park it other way but after sitting in flat ground it gives the issue 2 or 3 more times then starts like a champ

[Blendxmax300]

I wrote again the message because i dont know how to reply good

[roadster]

Possibly water or other contaminant in the fuel tank which is picked up when not on level ground? Perhaps another issue with methanol and stale fuel?

[Blendxmax300]

Possibly water or other contaminant in the fuel tank which is picked up when not on level ground? Perhaps another issue with methanol and stale fuel?

It is always happening when bike sits in the sun and uphill

When bike rests for the night and i wkae up in the mroning bike start in a second

[John A]

Does the bike have fuel injection, or a carburetor?

Your problem does sound sort of like Tmax fever. Might be worthwhile googling it to see if it does.

[roadster]

Possibly water or other contaminant in the fuel tank which is picked up when not on level ground? Perhaps another issue with methanol and stale fuel?

It is always happening when bike sits in the sun and uphill

When bike rests for the night and i wkae up in the mroning bike start in a second

In hot conditions fuel vaporization in the fuel lines can cause starvation until the vapor bleeds out and is replaced by fresh petrol. When engine is cold there is also enrichment, either auto choke or injection provides this, and any minor fuel quality or supply problems would be masked. Make sure that fuel lines are routed clear of hot engine parts and have not been moved from original positions.

[Ralph]

They have evap system that absorbs evaporated fuel and returns it to the inlet when conditions are right, if that's not working
properly it could cause a over rich mixture, if I overfill mine it will on leaving the garage often cut out the pick up again then
never does it again unless I overfill it.

[DTO]

If parked in full sun try a little throttle on start up , That’s what the Yamaha dealer told me to do ?