Ask Sail: Low Revs and Soot

I own a 1987 Catalina 27 with a Universal M18 diesel engine. I’ve had the boat for just over two years, but because the hour meter is broken, I don’t know how many hours are on the engine.
Author:
Publish date:

Andrew Gardner of Long Island, New York, asks:

I own a 1987 Catalina 27 with a Universal M18 diesel engine. I’ve had the boat for just over two years, but because the hour meter is broken, I don’t know how many hours are on the engine. The manual says maximum rpm is 3,200, but the most it will do out of gear is about 2,700 rpm (confirmed with a photo-sensor tachometer). It also stalls out below 1,000 rpm, and black soot accumulates on the transom.

I’ve replaced the injectors and fuel filters. I’ve changed the oil and oil filter several times. I’ve inspected the exhaust elbow and air intake for blockage. I’ve even tried feeding it fresh fuel from a jerry can, but I still can’t cure this. A compression test showed compression is right on spec. On the positive side, the engine starts right up and otherwise seems to run OK.

Nigel Calder Replies:

NigelCalder

Does your engine have a decompression lever? If so, check to ensure that it is not holding a valve cracked open. Otherwise, this could be something as simple as the throttle not advancing the fuel rack on the injection pump far enough. Have someone work the throttle while you look at the engine end to see whatever lever or rod it is moving. Try pushing this farther by hand and see what happens.

But this will not address the stalling and the black smoke. Did these problems precede or follow the injector replacement? If the latter, I would suspect an injector problem. Finally, a sticking governor could explain things, but this requires more disassembly to check out.

Got a question for our experts? Send it to sailmail@sailmagazine.com

Related

mcarthy-and-mouse

Experience: McCarthy and the Mouse

Sitting at the helm in a light breeze, my arms crusted with a fine rime of salt, my skin so dry I’d lost my fingerprints, I heard a clatter and a curse from below. There were only three of us a thousand miles from shore and only one on watch at a time. Usually, the off watch lay ...read more

2018-giftGuide

2018 Holiday Gift Guide

Brass Yacht Lamp Does someone on your gift list spend the whole winter missing the warm days on the water? Let them bring a little bit of nautical atmosphere home with this new lamp from Weems & Plath. The glass enclosure means the flame cannot be blown out even by ...read more

image001

Opinion: On Not Giving Up Sailing

E.B. White was 64 when he wrote his now-famous essay “The Sea and the Wind That Blows,” which begins as a romantic paean to sailing and then drifts, as if spun around by a pessimistic eddy of thought, into a reflection on selling his boat. Does an aging sailor quit while he’s ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com A Helping Hand  This is a real-world solution, and I expect correction by my betters. However, anyone whose seacocks are modern ball valves rather than the grand old tapered cone variety may care to ...read more

1812-JeanneaueNewsVideo

Jeanneau Sun Odyssey 410

Designed by Marc Lombard, the Sun Odyssey 410 shares much in common with her older siblings including of course, the walk-around deck. Other features that set the 410 apart from other models being introduced this year include the 410’s “negative bow” shape allowing for a longer ...read more

shutterstock_698968441

Cruising: The Bahamas

“The ‘Explorer’ chartbooks. All three.” “An unlocked phone. But good luck with BTC.” “Spam. It’s ‘spensive there!” These were just a few suggestions we received from fellow sailors who had cruised the Bahamas when we asked how to best prepare for the trip. In fact, several ...read more

windsensor

Gear: B&G Wind Sensors

Sense the Wind B&G has launched a new line of wind sensors, including the WS320, a wireless system that is suitable for masts up to 80ft. Wireless wind sensor technology has been hit-and-miss, with some users reporting intermittent signal failure on tall rigs, but B&G, citing ...read more