MerCruiser 8.1 HO - first long trip, want to reduce "mechanicals" anxiety

[spikedaddy99]

Who is Stee?

The guy who said drink beer!

 

[juggernaut1]

Here you go on the plug wires.

https://www.michiganmotorz.com/crusader-8-1l-ignition-wire-set-a-c-delco

 

[Stee6043]

The guy who said drink beer!

I think I'm starting to get a complex. Gotta ease off the practical advice around here.

 

[copb8tx]

Who is Stee?

I agree w/having the manifolds inspected. However, if I am going to have each one pulled for inspection, and pay the labor, shouldn't I just go ahead and replace them?

Absolutely. Just like when I do compression checks during inspections I always have them put in new plugs. If the boat fails inspection then, oh well, I donated a couple of hundred dollars in plugs.

 

[mrsrobinson]

Absolutely. Just like when I do compression checks during inspections I always have them put in new plugs. If the boat fails inspection then, oh well, I donated a couple of hundred dollars in plugs.

Ugh, I actually thought about that when the mechanic was doing compression checks.

 

[mrsrobinson]

I think I'm starting to get a complex. Gotta ease off the practical advice around here.

Haha, keep the jokes coming. I wanted to reply to that post however I think the DUI boating gods would have got after me.

 

[mrsrobinson]

Dumb question, do all Mercs have cool fuel systems? I've never noticed one in the engine bay.

My 2001 Regal 3780 with twin 7.4 MPIs was the first boat I saw them on. I found out the hard way when the clamp on the raw hose to one of them broke while under power.

 

[scoflaw]

Ugh, I actually thought about that when the mechanic was doing compression checks.

That would have been a good idea but if you do have a freshwater boat there is probably nothing wrong with the manifolds. Have a look/see, manifolds aren't as cheap as plugs.

 

[Pirate Lady]

Who is Stee?

I agree w/having the manifolds inspected. However, if I am going to have each one pulled for inspection, and pay the labor, shouldn't I just go ahead and replace them?

My mechanic spotted them when winterizing. A good mechanic can spot if bad without removing. So I just had mine replaced last month. Single engine 7.4 mercruiser parts, $1500 parts, $350 labor. Manifolds, risers, spacers, spark plugs, flappers.

 

[douglee25]

The cool fuel modules have a water inlet/outlet on the rear side. The starboard is easy to access from the middle of the boat, the port you have to lean over the drive to get to it, but it's easily accessible. These fittings tend to leak and have been redesigned about 3X. They don't sell the O-rings individually (square cut 0-ring), but you can make do with O-rings from Lowes/HD.

It takes qty (2) - #112 O-rings - #112 1/2"ID x 11/16"OD .103" Cross Section Square Profile - Can order from McMaster.

You can use qty (3) regular O-rings from Lowes - #10 size I believe.

 

[mrsrobinson]

My mechanic spotted them when winterizing. A good mechanic can spot if bad without removing. So I just had mine replaced last month. Single engine 7.4 mercruiser parts, $1500 parts, $350 labor. Manifolds, risers, spacers, spark plugs, flappers.

I've always looked for rust/leaks at the riser/manifold gasket and water flow at the exhaust. I also put a temp gun on them. What else can a mechanic look at?

 

[OllieC]

My 2001 Regal 3780 with twin 7.4 MPIs was the first boat I saw them on. I found out the hard way when the clamp on the raw hose to one of them broke while under power.

I'm not trying to hijack this thread, but I'm in the parts catalog under my S/N, and I don't think I have one of those cool fuels.

Here's some photos. I know I have the pump and water separating filter, that's obvious, I guess I don't know where the cooler is. It doesn't look like what you all are showing.

edit: Okay, I figured it out. I have Cool Fuel II I guess. Thanks for letting me interrupt. Carry on...

 

[Pirate Lady]

I've always looked for rust/leaks at the riser/manifold gasket and water flow at the exhaust. I also put a temp gun on them. What else can a mechanic look at?

It had rust leaks at the riser manifold gasket

 

[Soulshine]

Absolutely. Just like when I do compression checks during inspections I always have them put in new plugs. If the boat fails inspection then, oh well, I donated a couple of hundred dollars in plugs.

A couple of hundred bucks for 16 spark plugs? Details needed.

Unobtainium electrodes?

 

[mrsrobinson]

To summarize:

• Replace plugs/plug wires, carry extras on the boat
• Carry extra serpentine belt
• Carry extra IAC
• Replace raw water impellers - consider replacing housing
• Replace V-Drive fluid/filter
• Replace fuel water separator- carry extra on the boat
• Inspect fuel coolers
• Inspect IAC Muffler, consider replacing if missing
• Consider removing/inspecting at least one manifold/riser
• Make sure towing insurance is up to date
  
• Carry tools on the boat for all of the above
• Bring lots of beer for the trip
• Relax and enjoy the trip

A few pics of the girl, and of course, a 460 Sea Ray sitting next to her, and my other road toy

Sea Trail/Survey is tomorrow, probably jinxing myself with this thread.

 

[superwa]

I think that's a great idea. You would not have to worry about them for a good 3-5 years and would know when they were done. They are boat killers.

Who is Stee?

I agree w/having the manifolds inspected. However, if I am going to have each one pulled for inspection, and pay the labor, shouldn't I just go ahead and replace them?

 

[Pirate Lady]

A couple of hundred bucks for 16 spark plugs? Details needed.

Unobtainium electrodes?

Actually, I just put 4 NGK Iridium plugs in my Veloster, $48 on Amazon. So depending what he got I can see a couple hundred for 16. But the boat is getting AC or Autocraft since I replace every 40 hours, not every 100k miles.

 

[jmauld]

Here you go on the plug wires.

https://www.michiganmotorz.com/crusader-8-1l-ignition-wire-set-a-c-delco

Thank you for the link. I ordered two sets, but was just curious. What’s the difference between these and the plethora of 8.1L wire sets on summit racing?

 

[OllieC]

Actually, I just put 4 NGK Iridium plugs in my Veloster, $48 on Amazon. So depending what he got I can see a couple hundred for 16. But the boat is getting AC or Autocraft since I replace every 40 hours, not every 100k miles.

I would agree too. I paid $68 for 8 NGKs on Amazon as well.

 

[jmauld]

The cool fuel modules have a water inlet/outlet on the rear side. The starboard is easy to access from the middle of the boat, the port you have to lean over the drive to get to it, but it's easily accessible. These fittings tend to leak and have been redesigned about 3X. They don't sell the O-rings individually (square cut 0-ring), but you can make do with O-rings from Lowes/HD.

It takes qty (2) - #112 O-rings - #112 1/2"ID x 11/16"OD .103" Cross Section Square Profile - Can order from McMaster.

You can use qty (3) regular O-rings from Lowes - #10 size I believe.

Is there a good video on how these work and how to service them? I pulled the blue plug out the other day and black water dribbled out.