Today I had the opportunity to discuss proper operations of my R25's Yanmar 4BY2-150 engine with Bobby Kilker who works for MER Equipment in Seattle. Bobby is a certified Yanmar Field Service Technician. Here's what I learned from him.
Explanation for the "4BY2-150" engine designation
4 = number of engine cylinders
B = BMW (Yes, the auto maker. Yanmar took the BMW engine and marinized (sp?) it)
Y = Yanmar
2 = Engine revision level
150 = HP rating
1. Whenever possible run the 4BY2-150 engine at a minimum of 2600 RPM. This allows for proper level of turbo boost to keep the turbo seals seated in properly. Running with less than 2600 RPM for any extended time is AOK so long as the engine's RPMs are raised up to around 3600 for maybe 15 to 20 mins every 4 hrs.
2. The 4BY2-150 engine can be run all day at 3600 RPMs without issues.
3. If the 4BY2-150 engine is run at WOT with it being around 4000 RPM it should not be run at this RPM level for more than 30 mins.
4. Before shutting the 4BY2-150 engine down after a cruise place the throttle lever in neutral position, press the release button in the base of the throttle lever to disengage the gear box and move the throttle lever into reverse all the way (WOT) while holding the button in. Run the engine in this WOT 'throttle only' mode for some 15 to 30 seconds. Note that once the throttle lever has been moved into the reverse position you can let go of the button. This will ensure all the crud etc in the engine exhaust gets blown out and will avoid 'exhaust smoking' next time the engine is started.
5. When changing the gear box oil it's important to realize that the exit and return tubing that carries the gear box oil to the oil cooler need to be primed with the gear box oil. Thus, fill empty gear box with proper oil (it's almost invisible to see oil on the did stick) and when checking the level be sure to screw the dip stick in all the way (about 7 full turns) and fill until level is no higher than the top line marker on the dip stick. Now replace dip stick and screw in and perform the following to prime the two oil cooling tube/pipes with gear box oil.
Start engine and do following 4 times
1. Move throttle lever from neutral to just when forward engages and then immediately return lever to neutral and then continue moving lever to just engage reverse momentarily, and then back to neutral.
The above will prime the two input/output gear box oil cooling tubes.
Now remove the gear box dip stick and check oil level and top up as needed -- but be sure not to overfill beyond the top line.
As the oil is almost invisible to see on the shinny dip stick the best method for determining the oil level is to place the dip stick on a cloth after being removed from the gear box and then rotate the dip stick on the cloth to see where the oil residue resides with respect to the dip stick's top line.
I hope all this is useful to others... and BTW, Bobby will be at the Bremerton GTG Sep 10-13 so that will provide others the opportunity to go over all this grundgy detailed info again with him personally. 😉
Explanation for the "4BY2-150" engine designation
4 = number of engine cylinders
B = BMW (Yes, the auto maker. Yanmar took the BMW engine and marinized (sp?) it)
Y = Yanmar
2 = Engine revision level
150 = HP rating
1. Whenever possible run the 4BY2-150 engine at a minimum of 2600 RPM. This allows for proper level of turbo boost to keep the turbo seals seated in properly. Running with less than 2600 RPM for any extended time is AOK so long as the engine's RPMs are raised up to around 3600 for maybe 15 to 20 mins every 4 hrs.
2. The 4BY2-150 engine can be run all day at 3600 RPMs without issues.
3. If the 4BY2-150 engine is run at WOT with it being around 4000 RPM it should not be run at this RPM level for more than 30 mins.
4. Before shutting the 4BY2-150 engine down after a cruise place the throttle lever in neutral position, press the release button in the base of the throttle lever to disengage the gear box and move the throttle lever into reverse all the way (WOT) while holding the button in. Run the engine in this WOT 'throttle only' mode for some 15 to 30 seconds. Note that once the throttle lever has been moved into the reverse position you can let go of the button. This will ensure all the crud etc in the engine exhaust gets blown out and will avoid 'exhaust smoking' next time the engine is started.
5. When changing the gear box oil it's important to realize that the exit and return tubing that carries the gear box oil to the oil cooler need to be primed with the gear box oil. Thus, fill empty gear box with proper oil (it's almost invisible to see oil on the did stick) and when checking the level be sure to screw the dip stick in all the way (about 7 full turns) and fill until level is no higher than the top line marker on the dip stick. Now replace dip stick and screw in and perform the following to prime the two oil cooling tube/pipes with gear box oil.
Start engine and do following 4 times
1. Move throttle lever from neutral to just when forward engages and then immediately return lever to neutral and then continue moving lever to just engage reverse momentarily, and then back to neutral.
The above will prime the two input/output gear box oil cooling tubes.
Now remove the gear box dip stick and check oil level and top up as needed -- but be sure not to overfill beyond the top line.
As the oil is almost invisible to see on the shinny dip stick the best method for determining the oil level is to place the dip stick on a cloth after being removed from the gear box and then rotate the dip stick on the cloth to see where the oil residue resides with respect to the dip stick's top line.
I hope all this is useful to others... and BTW, Bobby will be at the Bremerton GTG Sep 10-13 so that will provide others the opportunity to go over all this grundgy detailed info again with him personally. 😉