Atomic Universal 5432 - Troubles

[Hershy]

The first time I took my newly installed, old but reconditioned engine, (Universal Atomic Diesel model 5432) out and tried to raise the rpm higher than 1900, under load, it refused. It would not go to 2000rpm.

Instead, black smoke belched from the exhaust and the exhaust water was oily-black all the way home.

With no load on it but the alternator, the engine runs sweetly, so I did not realise something is wrong in the months since having the engine installed, as I have been moored and fixing things and refitting. It was not until I got out into the bay and tried to see whether the engine would push my boat to hull speed that it showed me sometihng is wrong.

The boat is a 37' ALPA sloop (Italian from the mid 1970s). It had no engine when I took possession of it three months ago and had this reconditioned universal atomic 5432 installed in it.

At 1700rpm everything is fine with the engine, but its speed is only 4 kts. Hull speed is about 6.5 kts.

Any advice?

[FPNC]

What is the maximum engine RPM that can be attained in neutral?

You may be over propped. What is the gear reduction and what is the current prop type and size?

[Hershy]

In neutral it will happily go up to 3000 rpm and probably higher if I pushed the handle further. I don't, though.

If anything the boat is under-propped. The propeller is extremely fine. I don't have enough info on the transmission ratios gear reduction etc. But I was told by a surveryor who was looking at it informally when it was out of the water, that the prop is not aggressive...

[FPNC]

Originally Posted by Hershy

In neutral it will happily go up to 3000 rpm and probably higher if I pushed the handle further. I don't, though.

If anything the boat is under-propped. The propeller is extremely fine. I don't have enough info on the transmission ratios gear reduction etc. But I was told by a surveryor who was looking at it informally when it was out of the water, that the prop is not aggressive...

Okay then.

[capt jgw]

If not over propped then something else in the drive line may be binding and causing too much resistance. If it's in the transmission, it can only get worse. Is this the Hurth trans that normally comes on a Universal? They're known to be crap, but usually fail by slipping rather than binding up. The black smoke and soot means the engine is being over fueled. That usually means the engine can't turn as fast as the throttle setting calls for, ie over propped, but an injector pump or nozzle problem can be the cause. "Reconditioned" doesn't mean much, sometimes it just means "painted".

[FPNC]

Clean out your exhaust elbow.

[kenbo]

If the boat was moored for months both the bottom and prop could be severely fouled causing the symptoms you mention.

Without knowing the gearbox reduction and prop specifics not much beyond speculation can be made.

[kenbo]

I believe your boat was originally fitted with a 48hp Mercedes diesel. If the prop was original to that engine you are probably over propped for that 32hp Universal. But your details are lacking.