Reasons why 2-strokes run tight when hot

[sportston]

Possible reasons why your 2-strokes is running tight when hot;-
Lean mixture (such as caused by the leaking crankshaft oil seal in this particular case)
Clogged exhausts or exhaust ports
Excessively rich mixture (excess fuel washes the lubrication away causing heat build-up)
Incorrect spark plug (wrong heat rating or style of plug)
Timing too far advanced
Insuficient oil flow
Insufficient cooling due to clogged or damaged cooling fins or lack of airflow (aircooled strokers don't always like full fairings for this reason)
High carbon build-up
Overrevving
Extremely hot weather
Wrong size clearance between piston and cylinder walls
Scored bores

Just thought this might prove to be a useful checklist to share