The following letter appeared in Latitude 38's June edition. You may find
it very helpful:


THE ENGINE PROBLEM IS FINALLY SOLVED


We finally have a happy ending to the trials with our injector pump
which, you may remember, caused us to be late to the start of last year's
Ha-Ha. Readers might find it interesting in that it demonstrates how
complicated it can be to solve some engine problems.


The Problem: In normal conditions our 88-hp Yanmar diesel would power up
to 3,400 rpm under the load of our 20-inch Max Prop on our Tayana 52. But
we experienced a problem with the diesel auxiliary not powering over
2,000 rpm under the same load. The max output without load is 4,200 rpm.


The First Occurrence: We had no problem motorsailing into heavy weather
coming down from Anacortes, Washington, to San Francisco at 2200 to 2800
rpm - with 3,400 rpm on demand when we crossed breaking bars. On the
delivery from San Francisco to Newport Beach, we ran at 2,600 rpm until
Point Conception, at which time we slowed to 2,000 rpm for six hours.
When we tried to speed up again, the diesel would not go over 2,000 rpm,
even under full throttle. And the turbo would not spool up.


The Diagnostic Decision Tree: We quickly ran through our simple skills
without results. Through the efforts of a series of professional diesel
mechanics, we created the following diagnostic flow for debugging this
problem. Some of this was so simple, yet creative, it was worth taking
notes.


Suspected Problem - Restricted Fuel.


Step #1 - Visual inspection to see that there was plenty of fuel in both
tanks.


Step #2 - Visual inspection to see that the fuel filters didn't have air
or contamination.


Step #3 - Replace filters. Still no change in power.


Step #4 - Run engine off one gallon day tank connected to hose from the
top of the secondary filter. Still no change in power.


Step #5 - Replace secondary filter again. Still no change in power.


New Suspected Problem - Overpitched Prop.


Step #1 - Replace Max Prop with fixed 3-bladed prop that was originally
shipped with boat. No change in power.


New Suspected Problem - Restricted Air Flow


Step #1 - Remove exhaust pipe from engine and run under load. Still no
change in power.


Step #2 - Visually inspect turbine vanes by removing air breather.
Turbine spooled freely. Still no change in power.


New Suspected Problem - Lift Pump Failure


Step #1 - Hook up fuel straight to the injector pump by bypassing all
filters and lift pumps, and using a small electrical pump. Still no
change in power.


New Suspected Problem - Bad Injector Pump


Step #1 - Remove pump and bench test at specialty shop. Tested to specs.


Step #2 - Reinstall injector pump. Still no change in power.


New Suspected Problem - Bad Vacuum to Governor


Step #1 - Visual inspection. Hose all right.


Step #2 - Blow into hose. No air leaks. Still no change in power.


New Suspected Problem - Bad Injectors


Step #1 - Remove and POP test at mechanic. Tested all right. Still no
change in power.


New Suspected Problem - Bad Compression


Step #1 - Test each cylinder while injectors removed. Tested all right @
380 PSI.


New Suspected Problem - Bad Injector Pump


Step #1 - Remove and replace with new pump from Yanmar. Engine ran at
2,500 rpm and turbo spooled up. But still cannot achieve full power under
load.


New Suspected Problem - Overpitched Prop


Step #1 - Remove fixed 3-bladed prop and replace with Max Prop. Full
power at 3,200 rpm. Finally!


The lessons we learned:


1) At each step, the mechanic thought he had the problem solved. The
injector pump "never fails," and it tested OK. A mechanic did say
sometimes they test OK but don't work under real load conditions - which
are apparently hard to replicate on the bench. In any case, that was our
problem. We exhausted every other avenue before buying another injector
pump because it cost $1,600 - plus airfreight. We also had to wait for a
second replacement pump because the first one arrived with a hard
failure.


2) I always thought that boats that don't make the Ha-Ha or start late
were guilty of not trying hard enough. Well, we airfreighted two injector
pumps, and the first replacement one was bad. We drove to FedEx to pick
it up. We airfreighted the fixed 3-bladed prop to try it in place of the
Max Prop. We had two divers replace it while Beach Music was tied to the
Balboa YC, as there wasn't time to have the boat hauled. We used four
different mechanics to repair the engine because we had to move to San
Diego before the problem was fixed in order to make the start. After all
this effort and expense, we still had to start two days late - but we did
catch the fleet at Turtle Bay in time to make the beach party. In the
future, I will have new-found respect for other boats with technical
problems - rather than assuming they didn't try hard enough to make the
start.


3) Perseverance, time and money ultimately brings results.


Having been in Mexico for the season, we agree that cruisers down here
are obsessed with the weather. Even those who were groomed by the strong
winds on San Francisco Bay seem pretty timid.


We've been enjoying Profligate's reports from the Caribbean.


Kirby & Pam Coryell
Beach Music, Tayana 52
Northern California / Mexico