How far off can compression be before a bike wont start? My manual shows i should have between 80-120 with auto decompression engaged and I'm reading 90psi. My manual also shows if i back the exhaust valve out 2 turns i should have 180-215 and I ended up with 150psi. My first reading is on the low spectrum but within the range but second reading is 30psi short of the minimum. Would that be enough to cause bike to not start. Basics already covered, mechanical timing is good, strong blue spark, new fuel new plug. If I spray ether I get a hiccup but nothing promising.