We thought our engine was doing better after we regrounded it and put the new elbow on, but when we started her up on Saturday she was up to the same tricks - slow start, almost sounding like a hydraulic lock, and not starting until the 4th or 5th try. What to do, what to do. So we know we have two separate problems: 1) The starting issue, and 2) The RPM issue. I'll put some notes below on what we've done thus far, but continue on here with what's going on.
We left the Charleston Megadock at 7:30am this morning to head over to Pierside Boatworks (formerly Charleston Boatworks). Because of a tall ship sighting and the need to go look at it closely, we were a little late to arriving at Pierside so we pulled right into the travel lift well. They pulled us out with only minimal issues (mostly centered around finding the right spots to put the slings for the travel lift) and hung Pelican in the air for a powerwash.
I have to say - our bottom paint was in MUCH better shape than I expected. There was very little growth and it was mostly on the forward surfaces which get the most water movement wearing away at the paint. A powerwash took off almost all of the growth. Our through hulls, speed paddlewheel, propeller, strut and other vulnerable parts had a decent amount of barnacles, but the painted parts were good. I'm not disappointed that we hauled though - our waterline needs to be raised about 4 inches, and the hull above the current bottom paint was nasty. The other good news is that the keel looks in pretty decent shape. We definitely took ALL layers of paint off the bottom, but it's still pretty smooth and there are no chunks missing that would allow water intrusion. We may fair it a little, but it won't take much work. Kristen spent the afternoon with Interlux Heavy Duty Stain Remover cleaning Pelican's hull.
While Pelican is out of the water and getting painted we plan to do a complete compounding, polish and wax. In addition, we're going to put new WoodPro Plus (similar to varnish) on some of the trim pieces, remove the prop for servicing, install new zincs, possibly replace the cutlass bearing and do some more engine work. I spent most of the afternoon ordering products for cleaning Pelican and doing more research on our engine and RPM issues.
So I spoke with several critical people today with regards to our engine "issues". The first people I spoke with are the distributors of Gori propellers in the US. They still had the information from the original order in 2003 for the propeller and said that the engine, gear ratio and propeller pitch match up, and are what they would still recommend today. The person I spoke with did concur with my idea as to what the problem is - the propeller isn't coming out of "overdrive" mode. Our propeller is a feathering prop. In other words, the blades shift their pitch based on whether you are going in forward or reverse. The Gori props go one step further - in the "overdrive" mode, the blades are set in the reverse position but rotating forward. This setup radically increases the propeller thrust while reducing the RPMs necessary to reach that thrust level. In other words, if your boat normally moves at 6kts at 2800 RPM, going into overdrive mode would allow you to reach that speed at 2,000-2,200RPM instead. Sound familiar? There are also warnings that trying to reach higher revs while in overdrive mode may overstress the engine and cause overheating issues. Does that also sound familiar?
I then spoke with the owner of the company (Old Port Marine in CT) that repowered Pelican back in 2003. He was INCREDIBLY helpful with ideas. I have to say that I really appreciate getting customer service 6 years after a sale and when the sale was to a different person! He said that Pelican definitely was capable of reaching 3,000RPM+ under load when they first did the repower. In addition, he was adamant that our starting problem is due to a partial hydraulic lock and that the most likely culprit is the siphon break/vented loop on the exhaust. The reason for the intermittent aspect - sometimes we can start, sometimes we can't - is due to the fact that sometimes the loop is working, and sometimes it's not. Anyway, we're going to take his advice and replace the entire vented loop and see if that solves the problem. In addition, he recommended doing a complete flush of the coolant system and also cleaning the heat exchanger, so we're going to follow his suggestions.
With regards to the propeller, the distributor said that we can send it back to them and that they would inspect it, so we're going to do that. Tomorrow or Wednesday we're going to pull it off and overnight it up there to see if we can figure out what's going on. We'd love to leave Charleston with a working prop and a functioning engine.
Thanks to everyone for the very helpful suggestions we've received thus far! Your ideas are great and very appreciated. By the way - Cidnie asked if we have a Perkins engine, and we do not - it's a Yanmar 4JH3E.
For those interested, here's our current summary of what we've done with the engine thus far:
Here are a bunch of notes from various diagnostics we've done and some done by a very good diesel mechanic here in Charleston:
- Blew out the first starter by overcranking, so the starter was replaced 2 weeks ago with a brand new one.
- We get a little white smoke from the exhaust
- We get a small amount of unburnt diesel from the exhaust
- Both of the prior two items can be explained away due to the possible issue with the propeller
- No black smoke
- No blue smoke
- Slight moisture on oil fill cap. Still have to do oil change, but took some oil from dipstick, put it in foil, heated it and no crackle. Checked cap again today, no moisture.
- May be a SLIGHT sheen on coolant, but difficult to tell
- Did load test on battery and it was fine. Showed a weak ground on the engine, so regrounded directly to starter. Does not appear to be a problem with the switch - same issue occurs when bypassing the panel
- Thought there may be a carbon buildup in engine due to prop issue, so we pulled off exhaust elbow
- Good news - no carbon buildup
- Bad news - water came out, some sludge in there - obviously not a good thing
- Replaced the mixing elbow with a new one
- Unscrewed each injector nut and engine reacted properly
- Did compression test of cooling system and showed no pressure loss
- Have not done cylinder compression test - yet
- First time we started the engine after replacement it started right up - no delay, perfect start
- Turned on engine the next day, problem returned
- Ran the engine for 4 hours yesterday, checked mixing elbow today (12 hours later) and NO moisture.
- When engine is running, very smooth - no misfires, no weird sounds - mechanic said it purred.
- Can restart engine easily if it's been running for a while, you turn it off, and then turn it back on
- Seems that any time you change something (i.e. starter, filter, reground, etc.) engine starts right up, then is back to its old tricks the next day.
- New pressure test of the cooling system, but for 4-6 hours this time
- Check the injectors at start for water spray
- Remove and clean the heat exchanger
- Flush the cooling system and replace with Texaco Long Life Antifreeze
- Send the prop back to distributor for examination
- Yanmar 4JH3E engine
- 2.62 Gear Ratio
- 1.25" Shaft
- Gori 18 x 14 x 3RH propeller