Volvo Penta D2-75F starting in half throtle

[colonel]

The manual of Volvo Penta D2-75F recommends to start a cold engine in half throttle.
I used to start it always in off position. Now it starts only in half throttle. Or it takes few attempts if I try to start it in 'off' position.
It's only 20C outside so the engine is not really cold.

Fuel like seems to be OK. Pump is hard to press.

On my previous boat I had a Yanmar and never knew that it it should be started in half throttle. It was fine even in 5C outside.

So my question is could it be a sign that something is about to break?

[tkeithlu]

Loss of compression and a restriction in the fuel delivery could each cause that. So could a stretched or loose throttle cable. All could be more gradual than "about to break." Do you get full RPM and power once it's started? Are you getting any smoke after starting?

If it concerns you, the easy checks are the cable and the filters. Next might be a compression check.

[colonel]

Originally Posted by tkeithlu

Loss of compression and a restriction in the fuel delivery could each cause that. So could a stretched or loose throttle cable. All could be more gradual than "about to break." Do you get full RPM and power once it's started? Are you getting any smoke after starting?

Loss of compression was my first thought but the engine is only 400hours.
There is no RPM/power loss and no any smoke.
Everything is fine if started according to the manual.