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Old 08-16-2016, 12:59 PM   #1
Tengee
Member
 
City: MA
Country: United States
Join Date: Aug 2016
Posts: 12
Pacific Trawler performance

Hi - I am a new member to the forum and new owner of a 2000 Pacific Trawler 40, hull number 35. After 35 years of sailing, my wife and I decided to try a different kind of boating. We recently purchased our boat and even though it's only been a few months, we really love her. There is an issue with our boat, however, that I'd like to get some input from other PT owners in regards to the design and performance of their boat.

During the sea trial the we found that the engine would not achieve the specified RPM's. We have a John Deere 6068, 225 HP that is supposed to reach 2,600 RPM but we were only able to get 2,000 RPM under load. With no load, the engine comes up to 2,750 RPM, which is expected. There was no black exhaust at full throttle, so everyone expected the problem to be fuel related. The engine was also running a bit warmer than normal, close to 200 F. The bottom was freshly painted and clean.

To start with, we had a diesel mechanic look into the over temperature issue. He found the heat exchanger was partially plugged and had a partially collapsed exhaust hose. He felt the collapsed exhaust hose was most likely causing a restriction, which was the reason for the low RPM. The cooling system was cleaned and the exhaust hose replaced. We did another sea trial and the over heating situation was corrected but there was no improvement in the RPM's. Figuring the engine was not getting enough fuel, we changed the fuel filter on the engine and then attached a hose directly to the filter port and into a fresh can of fuel. The thought was to eliminate any possible fuel restrictions in the fuel line before the filter or bad fuel as being a possible cause. There was no improvement in the RPM's. The yard believed, therefore, that it was a prop issue or possibly the weight of the boat. They hauled the boat and verified that the prop was as listed (26 X 24) and the weight as advertised, which was 30,000 pounds loaded (listed at 26,000 empty).

We spoke to a local John Deere dealer and he felt it was most likely a lack of fuel that was causing the low RPM issue. He said that if he could get aboard, he would fix the problem. The boat was in Maine and our local JD mechanic was near where we planned to moor the boat in Massachusetts, so we went ahead with the purchase planning to have them troubleshoot the problem once the boat was home. We did place funds in an escrow account with the broker to be used to fix the RPM issue.

The boat ran fine on the trip down to Massachusetts, running at 1,900 RPM at a speed between 8.5 and 9 knots, which we expected. Once we got the boat home, we had the local JD mechanic aboard. He ran a series of tests along with a sea trial and felt that there was nothing wrong with the engine and that it was performing as would be expected. He brought the wrong fitting to test the pressure of the fuel at the engine filter, so we scheduled another visit. Upon his return, we tested the fuel pressures and did a few other tests and again he felt the engine was fine. His conclusion was that the pitch of the prop was probably incorrect and was causing the low RPM issue.

In the meantime I talked with three different propeller shops to get their thoughts. All three agreed that the 26 X 24 prop was the correct size and pitch for the boat, based on the design specs of the boat. They thought it was probably a lack of fuel that was the cause of the problem. So essentially, the engine guys feel it's a prop problem and the prop guys feel it's a fuel problem.

I figured the next best step, other than fiddling with the prop pitch, was to reach out to other Pacific Trawler owners to learn about the specifics of their boats to see how they compare to our boat. Hopefully, knowing these specs will help us to better understand what might be causing the low RPM's. Please understand that we are not hoping for a 12 knot boat but rather want to make sure the engine is performing as designed and at the correct RPM.

The specs of our boat are as follows:

- Pacific Trawler 40 with the open transom and integral swim platform. We also have the added fuel tank under the platform deck of around 185 gal.

- Weight is 30,000 pounds, fully loaded.

- Engine John Deere 6068, 225 HP, 2,600 RPM.

- Prop is 26" diameter, 24" pitch

- Speed at 2,000 RPM is around 9 knots, which is the maximum speed.

- Floscan reads 3.5 gal/hour at 1,700 RPM at 8 knots. Around 5 gal/hour at 1,900 RPM.

I would appreciate any information other PT owners might have that would help us diagnose this problem.

Thanks and I look forward to hearing from you.

Jim
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