Yanmar 3QM30 questions

[Jerry]

Can anyone help me with the following questions? I have the Yanmar service manual but can't seem to find the info I am searching for.

1. How do you tell the difference between a 3QM30H & 3QM30Y? I know that the F model is fresh water cooled.

2. What is the operating temperature of the 3QM30 in Farhenhite?

Thanks for your help,
Jerry

[Richhh]

The chief differences that can be identified are the model number of the transmission and the overall engine/trans. length.

The 3QM30H uses a KH18 Trans. (Kanzaki ??); the 3QM30Y uses a YP-10M trans. Check the model number on the transmission cover.

Dimensions between front to rear engine mounts (centerhole-centerhole):
The 3QM30H overall length front flange of the water pump to rear output flange is 37.5 inches. The distance between the centerhole of the front to back engine mounting flange (fits with the rubber engine mount) is 21.22 inches
The 3QM30Y overall length front flange of the water pump to rear output flange is 36.93 inches. The distance between the centerhole of the front to back engine mounting flange (fits with the rubber engine mount) is 22.20 inches

For both, the engine with raw water cooling, T'stat should 'open' at approx 135 deg. F.; for Fresh water cooling the Thermostat should be open by '180' deg. F. My FWC 3QM30 at cruising speed operates at about 190 deg. F. when the inlet raw cooling water is about 70 deg. F.