I have a saito 72 in a Venus 40 and this is my first 4stroke. It feels like it has almost no compression ( its new never run) is this normal for a 4stroke. I have 3 OS 46 motors and they all have a ton of compression.
I checked every thing for tightness and I cant hear any air escaping.
Should I send it back or is this normal for a 4 ?
TIA

Yes, it can be normal for a new four-stroke of any brand not to have much compression. It will improve tremendously after the break-in ritual.


Ed Cregger

On a four stroke, make sure the throttle is open a little or it will not have any compression.

thanks for the replies. its was kinda bugging me

Had the same thing with a new 91. Spun it over with an electric starter and it was OK???

bugugly. This sound like your first four stroke. I like to pull the valve covers before the first run. I check the valve clearance and run some oil down the pushrod tubes. This will make sure the cam is lubed during the first start up. I use my after run oil which is a 50/50 mix of ATF and Marvel Mystery Oil.

David

thanks ... that sounds like a good idea