If you want to do a compression tester on a bike carb engine, do u do the following please:

1) remove carbs

2) leave just intake mani on

3)remove all spark plugs

4) crank engine with gauge in spark hole

whats cranks the engine if there is no spark and fuel. is it the starter motor that turns it enough.

I'm buying a gunson from ebay

Nothing different to testing the compression on an injected engine, remove power (fuse) for fuel pump/s, Plugs out, screw tester into plug hole, foot fully down on accelerator pedal, crank the engine over, make a note of the reading, repeat for the other cylinders, there shouldn't be more than 10% between the readings, if they are all on the low side, put a small amount of oil down the plug holes and then repeat the test, if the readings increase, you have worn bores/piston rings, if the reading stays low it's worn valves

What about the fuel still left in the carb float bowl

Bike carbs have a screw for each bowl (4) to drain the fuel out the bowls

thanks. Just thought it would be easier to take the carbs off. then the inlet manifold would be fully open at all times.

then don't need to depress pedal

Edited 24 June, 201511 yr by damunk