Sticky patch on engine?

[lawrence_craig]

Hi all,

I recently took ownership of this boat.

Whilst fixing an issue (core plug), I notice the previous owner has taped over a hole in the gearbox. I’m guessing the tape isn’t supposed to be there! What is supposed to be there? Will it be having any detrimental effect?

Many thanks

[a64pilot]

I believe that is the bell housing, there appears to have been some form of cap that was there, but tape will work fine too. You may be able order the correct part.

[DeepFrz]

It's not on the gear box itself but on the Bell Housing so no problem. There are no lubricants there but I'm not sure what the hole is for. Possibly for inspection of the anti-vibration plate. I recommend that you fabricate a metal plate to cover it though.

Oops, didn't see the previous post.

[model 10]

If you look in there you will probably see the flywheel teeth. You could do several things with that hole but tape works to cover it up.

[dennismenace111]

There was probably a magnetic sensor that "counted" teeth on the flywheel for the Tachometer. The PO probably changed the alternator with a tach lead and also changed the Tachometer. The alternator version of tachometer source is more accurate and more reliable.

[lawrence_craig]

Great, makes sense, thanks guys

[dennismenace111]

Is it a Yanmar engine?

[lawrence_craig]

Volvo Penta D2-55

[DougR]

As you can see from the flywheel housing photo, the engine was delivered with a plastic plug placed in the hole next to the Perkins badge, which is covered by tape on your engine. The tach inductive pickup is located in the hole to the left of the hole in question.

The inductive tach pickup is superior to an alternator driven tach.... No worries about belt slippage, odd ball sized pulleys, etc. The notches machined into the flywheel never change, slip, or quit charging.

Just put a fresh piece of tape on it, or look around for some other type of plug......maybe the cork from a bottle of bubbly!

DougR

[a64pilot]

Originally Posted by dennismenace111

There was probably a magnetic sensor that "counted" teeth on the flywheel for the Tachometer. The PO probably changed the alternator with a tach lead and also changed the Tachometer. The alternator version of tachometer source is more accurate and more reliable.

It’s really not, the inductive tach is incredibly accurate and nearly bullet proof as all it is a Hall effect sensor.
Using an alternator to determine engine RPM is ridiculous in my opinion, but I guess it must save some money.

[Boatyarddog]

Originally Posted by lawrence_craig

Hi all,

I recently took ownership of this boat.

Whilst fixing an issue (core plug), I notice the previous owner has taped over a hole in the gearbox. I’m guessing the tape isn’t supposed to be there! What is supposed to be there? Will it be having any detrimental effect?

Many thanks

Attachment 195489

Attachment 195490

Most likely a port for setting injector timing.
There may be a pointer if you look down with a flashlight.
Just recover it.
Cheers,
SV Cloud Duster

[a64pilot]

I just noticed what looks to be a clear hose, what fluid does that hose carry?

[lawrence_craig]

Originally Posted by a64pilot

I just noticed what looks to be a clear hose, what fluid does that hose carry?

That’s the anti-siphon hose

[a64pilot]

Originally Posted by lawrence_craig

That’s the anti-siphon hose

Then it should be changed out with below deck rated hose in my opinion, I’m not aware of any clear hose that meets specs, there may be, just I’ve not heard of it if there is.

[dennismenace111]

Mine isn't! I replaced the tach but still have problems. The hall effect sensor stops providing signal after about 30 minutes of running at cruise power when I throttle down to open a draw bridge. It won't provide signal again till the next morning when it cools.

One would think that since there are no moving parts that it would be extremely unlikely that it would fail. Mine is failing.

I get just under 2v AC measured at the tach when it works. I get Zero volts AC when it quits!

I've invested $150 in a new tach now it looks like another $125 for a new sensor!