My Yanmar 4JH is now needing lots of throttle to start.

[Privilege]

After a recent service, during which I removed the injectors, replaced the fuel filters and starter motor) my 4JH 3e Yanmar, which has less than 500 hrs, now needs a lot of throttle to start. It starts first time but I have to push the throttle almost full in neutral to get it to fire up. I’ve put five hours on the engine since it was serviced but it’s still the same. Any idea what might be causing this? Would any trapped air have worked it’s way out by now? Thanks in advance.

[Compass790]

If there is no sign of an injector leaking from the combustion chamber the most likely problem is air intrusion. It's very common to have problems after changing fuel filters.
Check all your fuel line connections & go thru the bleeding steps as outlined in the service manual if you have one.
Someone with your engine may have specific advice for you.

[bstreep]

I second Compass's thoughts. Sounds like an air leak somewhere.