CAT 3412 won't throttle up?

I do not believe the overheating issue is related to the port engine not revving up. The overheating issue is most likely a result of a partially clogged heat exchanger which will require a chemical flush. What is the max. rpm achieved on the port engine? Is there a permanent alarm being displayed on the port engine instruments which could be forcing the engine into protection or emercency mode? If no permanent alarms are present and your port engine is only reaching a lower rpm than usual and is unable to rev past it, then I would suspect a fuel supply problem or blocked fuel filters.

What throttle control do you have? Not running, key on, push the throttle to WOT, make sure the governor moves to WOT.

Had a boat with B+ issues with old mathers controls doing the same thing.

This is my guess. Probably need a Cat guy to clear the computer code.

3412s did not have that fancy of a computer.
You still have not explained what rpm you are getting.
Nor what controls you have.

3412 or 3412E?

210 is way too high. What RPM were you running. Even 190 is a bit high depending on RPM. How about the gear temps?

That shouldnt prevent the engine from reving up. Does it just stay at idle? How about in neutral, will it rev up? Sound like a control issue

Ah, Kobelt controls. No experience there.
But I think I was close.
Please keep us up as I'd like to learn more about these fancy controllers.

Also, My past with 3412s with ZF clutches, a side line after the Sherwood pump goes off to cool an internal H/E.
It's a small hose (1/2"?). I have back flushed these with dock water. Some trash did come out.
The later 3412s I've been with had the fancy stacked plate H/Es, If your is the round monster, the end caps offer a good inspection option.
I think rather large rods that may be easy to clear if they have any restrictions.
You just may find one end cap full of trash that a chemical cleaning may not clear anyway (old impeller bits, plastic, sediment and grass goo).

I m familiar with the 3412Es not the ealier ones. The 3412Es have a gear cooler on the ZF. Typically the first symptom of an impeller issues was always the gear running 20 degrees warmer at idle speed. Go back at 1000 or higher and the gear temp would come back down.

The 3412Es have fuel cooler BEFORE the raw water pump. Anything making thru the strainers ends up trapped at the fuel cooler inlet. They need cleaning every once in a while. Not sure if this applies to the earlier 3412

How old are the impellers?

I d suggest you call southshore diesel. They really in miami but also cover Very reasonable and quality work. Marcello, the owner, has been doing my cat work for 10 years. He also surveyed the Lazzara I run (C32s). They just did impellers and service on ours. Good guy

Stay away from pantropic.

Other pump?
Other HE (heat Exchanger) for the ZF clutches. I remember internal in the ZF clutch.
Off of same main engine Sherwood (Shurfail) raw water pump.
You may have a power steering pump the size of a beer can somewhere.

I forget where the fuel cooler is. Think Pascal is on that if it's a multi tube Pack.

Heed Pascal comment; "Stay away from pantropic".
They have already bent over two of our customers.

Remove the engine sea water pump impeller and carry out the chemical flush from the sea water inlet hose pipe just after the strainer. You will be flushing the complete sea water cooling system which also includes the transmission cooling system.

If you remove the heat exchanger end cap you will be able to see the extent of blockage.

Agreed

I can not find Kobalt controls anywhere. Nothing on the web. Never operated such an gizmo.
We may have an auto spell check kicking in on somebody's pad or kbd.
Not knowing anything about them, I have operated Kobelt controls of many types. All were very fine.
Never worked on them at all.

Of course, please keep us up on the fix and suspect failure cause.

I hope you had a good time in Miami / K B.

They were and they're old, antiquated, dangerous junk that should be replaced. When they hiccup they stay at whatever throttle and gear setting they were at. They don't like voltage spikes or drops either. They still sell them, but haven't seen them on a boat in a million years. Not sure if they've fixed their inherent problems, but the current control heads look just like they did in the 1980's. I've dealt with them in the past, but the ones that took the cake were shraeder bellows electronic air operated controls of which they only made 24 sets of, and I was blessed to manage a yacht that had one of those sets.

The shraeder bellows was the only 24 volt system on the boat (58' Striker) and it had 2 waverunner batteries, with it's own charger that plugged into a GFCI 120 volt outlet in the engine room. The wires going to each station were the size of telephone wires.....tiny gauge. You then needed a generator, and air compressor running so the solenoids would shift and give rpm's. Lose any 1 of those and you were up a creek but at least in neutral,zero throttle.