At Anchor

At Anchor
Whiskyjack at anchor in Garrison Bay, San Juan Island

Tuesday, April 24, 2012

I'm pickin' up (good) vibrations? Enough for all winter!

"I'm pickin' up good vibrations, she's giving me excitations'" so go the lyrics of the 1960's Beach Boys song.  It all began with a little vibration!  Last year I notice that I was getting a vibration when I advanced the throttle over about 2500 RPM.  Nothing to worry about, I thought, because I cruise around 2000 RPM.  But once I feel something like that my mind begins to wander and I start thinking about fixing it.  I knew from the purchase survey that I would need a new prop sooner, rather than later.  So, in the fall of 2011 we hauled the boat at Rocky Point Marina and I installed a new Campbell Sailor prop.

And what a beauty that prop was!  I couldn't wait  to get WhiskyJack back in the water and try it out.  And what a surprise that was.  I left the Rocky Point Marina and headed back toward my my slip a mile or two away.  I throttled up and was surprised that I couldn't get over 1900 RPM without black smoke from the exhaust the boat was flat out at 2200 RPM and blowing black smoke like a steam locomotive.  What's wrong here?  Too much pitch?  Bad prop?

I called West by North to discuss the issue with them.  I was assured that the prop was what it supposed to be and that my engine should turn that screw (I already knew that).  WxN was very helpful and pointed me in the direction of a common problem with the small Yanmar engines.  "Have you checked your exhaust elbow?" they asked.  "They have a tendency to plug up with a sooty deposit and inhibit the exhaust from being discharged.  Have you checked it lately?"  Right, that's certainly something that I check regularly---NOT!  But what a great suggestion.  I thanked them and immediately knew what II was going to be doing the following Saturday.  They ran through some other possibilities but I was not listening.

The following Saturday, I began the task of swapping out the exhaust elbow.  A couple of years earlier I had noticed an exhaust elbow on eBay and bought it for a very reasonable price, thinking that I would need it someday.  That day was today.  The exhaust hose was cut off and the elbow came off with a large pipe wrench with very little trouble.  When I looked into the discharge side of the elbow I saw a large deposit of soot, nearly blocking the passage.  Eureka!  That's it.  What an easy fix.  A trip to West Marine and I had some new exhaust hose.  The new elbow went on without a hitch and I was back in business.  I could wait to finally test the new prop.

Boy, was I surprised when there was little change in the max RPM or the amount of black smoke being produced.  What were those other possibilities for low engine power?  Oh, yes, the injectors!  The Yanmar 2QM15 in WhiskyJack has 2200 hrs and does not appear to have had any major overhauls.  I received a thorough briefing from her previous owner at the time of purchase and no mention was made to anything being done to the engines.  The maintenance manual suggests inspection at 500 hours and that has surely come and gone.  Any what about the small amount of oil coming out of the air intake.  Could that be a sign of a leaking valve stem seal?  My fate was sealed:  The head was coming off.

The winter's project was before me:  While the engine was apart a change in the engine instrumentation and alarm system seemed to make sense.  What about a new alternator (I never liked nor trusted the one I installed 5 years ago), and with the new alternator shouldn't I install the Xantrex Link 10 I bought on sale a last year?  And what about changing from raw water cooling to fresh water cooling?  I already have the heat exchanger.  Let's do that too.  Boy, I hope it's a long winter.

No comments:

Post a Comment