Marlin Not Tracking Well

[ret]

We purchased a used 1999 Marlin in the fall of 2009 and put 150 hrs on her this season so far. My family loves the boat, as do I, except that it is not tracking well to say the least. Yesterday, in mild 2-3ft following sea I was working hard to keep control of the boat. That's the problem I'm hoping to correct, because I'm sure something isn't configured right.

She was re-powered with 2004 Yamaha 225hp 4-strokes. Prior to purchasing (from a dealer), it was identified that the wiring was incorrectly installed. The dealer reconfigured the wiring and provided 4 new batteries and off we went.

Some research suggested that if thje engines weren't set at the proper elevation ("pin setting") that could cause tracking problems. I observed 4 pin settings (ie the spot where the bolt passes thru the engine bracket and fastens to the transom). The engines are mounted using the 2nd setting from the top.

What is the correct setting or how do I confirm this? Are there other possible causes for the tracking problem.

Thank you for any advice.

 

[BobP]

In the following seas, where was boat trim set and motor trim set?
How much fuel in boat?

 

[grady33]

While fishing yesterday in 3-5 with 4 sec period - it was hard to keep my Sailfish straight in a following sea. Sometimes when the winds and current are opposite, a boat can be caught in the middle - making it hard to keep on course. I think this would be the case with any boat.

 

[Gary M]

My 2001 Marlin (250 OX-66s) does not track well in following seas of 3-4 feet. I try to use the A/P but when I see heading changes of +/- 20 degrees or more, I take over and hand steer where I can usually hold it to about 10-15 degrees +/-.

 

[NOTHING ELSE MATTERS]

In general, all boats don't track well in following seas, especially if you keep the speed up. You have a big flat stern that is pushed by the wave and a sharp entry that likes to wander around, if you were in following seas, then no problem with your boat or settings on the boat.

 

[Gman25]

Try bringing the trim tabs all the way up and trim the outboards up to get that bow out of the water. My guess is that you have too much bow digging into the water. That hull will blast right through a following 2-3 with ease.

'05 300 Marlin F250's

 

[ret]

Gman25. Thx, she is handling just like she's bow heavy. The tracking issue isn't limited to a following sea, its amplified in those conditions. Perhaps I should shift as much weight aft as can reasonably be done.

 

[georgemjr]

What holes are other's outboards mounted in. this could provide insight into making sure his are correctly mounted. Beyond that it is a matter of trim...

 

[Gman25]

Gman25. Thx, she is handling just like she's bow heavy. The tracking issue isn't limited to a following sea, its amplified in those conditions. Perhaps I should shift as much weight aft as can reasonably be done.

I really dont think shifting anything you may have in the bow to the stern is going to make any difference with that hull. Its a heavy boat. Like I said retract the trim tabs all the way up. Then trim up the outboards far enough that you can still get up on plane. Figure start with 2-3 blocks on your tach...then when your up on plane trim a bit more but not too much that the prop is losing its bite causing the tach to become erratic. If you start to pound into waves trim the engines down a LITTLE AT A TIME..You just dont want to bury the engines into the transom. Now as far as the trim tabs go while both are up as far as they go..if for example you are leaning port and need to raise the port to be level, press the right top button to level it out. If you pressed it too long and now your leaning stbd then press the right bottom button to bring it back up. Opposite applies if your leaning the other way...Hope this helps

'05 300 Marlin F250's

 

[NO REGRETS]

Trim the bow up and be sure the cabin isn't overly stuffed.By stuffed I mean with too much stored baggage.Also it may be your using too much tab.In following seas you want the bow up a bit so when coming down a wave it carves a slight path not digging in.And, it's possible you were going too slow or too fast for the condition you were in.There is never a set it and forget it trim or speed setting.Faster usually is better, around 3800 to 4500 should be where you were rpm wise. Always error on the bow being high and your trim tabs at minimums, you will be suprised.You almost want the boat to reach out to the next wave not to go down the face of the one you just overtook. :dance If your pounding at all put the moters down a bit before using trim tabs.Use the motors for attitude adjustments before going to the tabs.Only use the tabs for leveling side to side and the motors for bow up or down, see if that eliminates your bow steering. :wink:

P.S.- be sure your not holding water in the bow, that never helps! :goodjob

 

[gerrys]

ret:
You are indeed correct that the Marlin is a bow heavy boat, but it shouldn't cause major issues.

At what speeds is the issue occurring (I'm guessing at displacement speeds)? I can't imagine a tracking problem at planing speeds.

At displacement speeds and a following sea/current, the tabs should be fully retracted and the motors in an upward trim. Heading into a strong head sea/current at displacement speeds, you may experience some bow steer that can be minimized by trimming the motors up.

With the Marlin fore and aft weight distribution, I have found a need to use tabs only to correct port/starboard weight distribution or to improve ride in a quartering sea or into a head-sea chop to plow throug, rather than over, the chop.

 

[megabytes]

Mine tracks fine. Something is not right. I agree with trim tab comments. They can cause bow steer in following seas.

 

[georgemjr]

In addition to all these helpful comments can anyone tell him what holes their motors are bolted through. He was trying to determine if his were mounted right to eliminate that from the possible problems...

 

[NO REGRETS]

mine are on the 2nd hole from the top.

 

[ahill]

I've posted many times on this subject especially bad in even a small cross sea.
I contend that when Grady changed the Sailfish & Marlin from the stepped transom to full running bottom they added to much buoyancy aft driving the bow down.
I'm sorry to hear this as I'm seriously looking at moving away from my Sailfish into a '99 Marlin for added size and to get away from the bow dig.
Maybe look at '95 and repower, refurb.

 

[ret]

Thanks everyone for your comments. I wasn't aware of a hull design change, I'll look into that. I am still experiencing walking with the tabs up and engines trim up at planing speed. The walking I'm referring to is when I'm attempting to hold a course (even in calm seas) the boat will drift to either port or starboard. It takes excessive correction (720 degrees at least on the helm) to bring her back and then it starts all over again. It's like, as has been mentioned by others, she's bow heavy.

I'd like to talk with Grady ao see what they recommend for the pin height for my model engine (I'm not encouraged that NO REGRETS is the same setting as my, I hoping perhaps shaft length is different).

Thanks again.

 

[NO REGRETS]

Be sure you don't have any air in the steering lines.This could add to you having to correct all the time.Also be sure the engines are aligned properly.Be sure that the engines are pushing in a uniform direction and one is Not pushing in a direction fighting the other. :hmm

 

[ret]

Good suggestions NO REGRETS, I'll look into the possibility of air in the lines and the alignments. The air has me particularly intrigued because it seems as though modest corrections are ineffective and that lkittle issue could solve the much larger issue. I'll let you know via a follow-up post once I have that figured out.

Thanks for your thoughts and effort.

 

[BobP]

Try running with both fuel cells more full than closer to low, keep the aux tank full all the time if you have two tanks.

All cabin boat models are bow heavy relative to center consoles, big difference in performance.

You should be able to lift the bow up with motor trim, but the boat is heavy cabin forward - makes sense looking at cabin boats.

I bet one/two sitting in the fold out bench seat at the stern makes a difference, as well as the fuel payload, and keeping crew/children out of the cabin while underway.

 

[BobP]

And make sure the cabin bilge/anchor locker is draining to stern, if water is blocked up forward same will occur.

I never heard of complaints like this with the Marlin, so check the drainage.
It is possible those lines are plugged even as delivered from the factory.

Take the dock hose and drop it into the anchor locker down low below the anchor line, right at keel line, and see if water passes thru cabin floor to stern, at rest may settle in cabin area but will pass to stern bilge upon adding gas to rise bow to plane.

Water is very heavy.