Diesel Yanmar inboard 4LHA-STZP

[morrisa]

Hi,
does anyone have information on the sea water cooling set up for this engine, the information I need is not in the manuel regarding the connection to the exhaust mixing elbow. Barrus have not been any help, I have waited 3 weeks now for information from them. The main problem is whether this set up should have an overflow from the top of the exhaust back to the out drive bravo 2, there is a place there for a 45 degree elbow but no information on it.
Morrie.

 

[makkers]

Welcome to the Forum.

I have the 4LHA-STP but on the Bravo III but cant answer your question.

You could try posting here...... Yanmar Forum

Or call these guys..... Marine Power

good luck.

 

[duncan]

I'll echo Jason's comment.
I have a BIII too and it has a water pick up that delivers to the elbow (it is not an overflow but the BIII has a seperate pick up that cools the drive then exits via the elbow). If the BII has the same arrangement then it will need connecting up or the drive will overheat.
Dave Swain is pretty quick to respond over on the Yanmar forum he runs. Failing that I would simply ask Mercruiser direct via Email - it's a BII issue rather than Yanmar.
Good luck.

 

[morrisa]

Thanks for both replies, I will try the Yanmar forum. The inlet from the gimbal housing connects to the sea water pump along with a supply from a seperate sea cock, this other connection is next to the inlet on the gimbal housing and is blanked at the moment.
How do you rate the 4LHA engine?
Morrie.

 

[mercman]

Onthe transom plate you have a plastic elbow with 2 bolts. The pipe comes of this and tucks behind the power steering ram. This goes to a joiner which is screwed to the transom. The other pipe from this goes down to the port side of the engine to a water mixer. The water mixer also has the water intake from the seacock on (1.5" diameter). Then another outlet which is 1 3/4" diameter this goes to the sea strainer then to the sea pump.
Now going back to the transom were the plastic hose tail is is a blanking plug which needs a large allen key to remove it. A brass 45 degree elbow goes here. Then there is a pipe which goes on this then up to the exhaust elbow where there is a 45 degree elbow. This is for relieving excess back pressure. It should be installed on all 4LH-STZP installs.

 

[mercman]

Disagree with your comments regarding its a B2 issue this pipework setup is relevant on all Bravo installs.

 

[duncan]

Sorry if my comment was misleading, and reading it again I can see it was! I was trying to say that there might be differences between the BII and BIII set up - thanks for you clear post.

 

[morrisa]

Thanks for all the information, I have now removed the plug with a 5/16 alan key and installed the elbow and connecting hose to the the exhaust mixing elbow. I can not understand why this information is not available in the installation manual supplied with the engine. The plug was extremly tight to remove and not much space to work in now that the engine is in place. I understand the rest of the system but was not supplied with the 3 way connector and again this information is not in the installation manual.
Morrie.

 

[mercman]

If you have run the boat before and now you have fitted the back pressure pipe you should notice a bit more power....good luck

 

[spannerman]

Sorry but the previous responses are now out of date, the latest from Yanmar now to us dealers regarding new installations is that you don't remove the plug in the shield, the hose from the 'T' piece on the exhaust bend now exits through the transom by means of a stainless fitting available from Yanmar or cheaper from your local chandler! and acts as a shower by splashing over the top of the drive, makes the install a lot easier and tidier around the back of the motor.

 

[mercman]

Sorry disagree that is an option you can do either and i can post official literature from Yanmar USA and Barrus on this post. My company have currently fitted over 100 yanmar 240-315 engines to ribs and sports boats and currently seen as one of the largest supplier/installer. Depending on the installation depends on what you do on the t-piece. 99 percent of install are thru the transom. Its mainly hi-speed boats that we fit the shower to.

 

[morrisa]

Thanks for that last bit of information. I have another query regarding my gear lube oil for the Z drive. The resorvoir level is OK but when I operate the tilt and trim past a certain level on the down movement the warning light for the gear lube comes on. Any ideas please?
Morrie.