Who can guess the deal with my 8v92s?

[JuiceClark]

I'm starting to work in the ER and address the last few big projects. The primary challenge remaining with the boat is it won't plane because it won't run above 1,400 rpm. Under no load, same thing - only about 1,400 for BOTH engines. The throttles slide nicely all the way, but acceleration stops half way up.

The PO said his "great mechanic" tuned the idle and set the govs. So, I went through his receipts, found that mechanic and called him. Mechanic said he always sets the loaded RPM to 2,300 and has never set it under 2,000 in his entire career. He checked his notes and said they were idling and running perfectly when last checked - 5 years ago! He never adjusted the rack or made any significant changes. So, I'll get a different great mechanic to come out in the next few weeks. (know any in Fort Myers?)

But what's your guess? It would be impressive if we could figure it out before the pro's visit. Hell, the mysteries are all the fun with these projects.

The bottom is clean and the engines don't smoke at all. Cleanest DDs I've ever had. When I first brought her home, there was a tiny dark bit of smoke at startup, but that has gone with regular use.
I checked each turbo and they're turning easily. They were new in 2016, not rebuilt. Filters are immaculate. Racors are clean with new filters. Props are clean. No vibrations up to 1,400.

Could it be the cables? The handsets were laughably screwed-up. Maybe the cables were mishandled somewhere else? Cockpit and tower have controls as well. They all slide the full motion, but something is preventing more than 1,400.

The synchronizer is a mystery to me. I'll have to read the manual and figure it out. Could the problem be in there somewhere with the cables to and from the sync? I have had the unit turned off at the breaker.

Them BOTH stopping at 1,400 is what perplexes me. It could be any engine-related thing, but both the same deal? So weird.

What's your guess? Imma' go through every suggestion!

[rwaldrop13]

You need to call Fleet Marine and Repair. Gary and Travis, father & son company. Incredibly knowledgeable and good guys. 239-945-2173

Fleet Repair and Marine - Boat Repair, Dometic, Vacuflush

Do me a favor - Tell them Rob at Legacy Harbor referred you, watch them face-palm.

They're fantastic.

[JuiceClark]

You need to call Fleet Marine and Repair. Gary and Travis, father & son company. Incredibly knowledgeable and good guys. 239-945-2173

Fleet Repair and Marine - Boat Repair, Dometic, Vacuflush

Do me a favor - Tell them Rob at Legacy Harbor referred you, watch them face-palm.

They're fantastic.

Thanks. I have Ross from Classic Yacht coming in a few weeks, too. I have a few other things for them as well.

Still, I'd bet we can solve this freakin' mystery. It has to be something stupid. There's no way both motors would run perfectly and stop accelerating at the same RPM. The odds are astronomical.

[madhatter1]

If you are using the synch and master English be won’t go over 1400 the slave won’t either. Need to plane off manually and then engage synch. Especially if there are problems.

[madhatter1]

If you are using the synch and master English be won’t go over 1400 the slave won’t either. Need to plane off manually and then engage synch. Especially if there are problems.

Master engine!

[JuiceClark]

If you are using the synch and master English be won’t go over 1400 the slave won’t either. Need to plane off manually and then engage synch. Especially if there are problems.

Yeah, I've had the breaker off on the sync and figured it would just not affect anything....but now I'm wondering if that's the case. All the helm switches get power from the panel up there. I haven't even thrown the sync switch on the helm while running, but a bunch of other stuff wasn't wired right up there.

Still, I took both throttles together and pushed them all the way forward. It stops accelerating both at 1,400, only half way.

[Captain Ralph]

When was the last time it ran correctly?
Are you using the sync when running and both stop at the same rpm?
Hynautic engine controls (hydraulic)?

This may help find an issue.
Sync off.
Disconnect the throttle cables from the engines.
Push the helm throttle controls to max (engine NOT running).
Go to the engines and pull / push the engine throttle levers to full fuel (engine NOT running), vice grips may help.
Ensure the ends of the lever and cables are at the same place.

It is amazing how many times this proves cables have been messed with. Usually when someone tries to match the helm throttle control levers.

[JuiceClark]

When was the last time it ran correctly?
Are you using the sync when running and both stop at the same rpm?
Hynautic engine controls (hydraulic)?

This may help find an issue.
Sync off.
Disconnect the throttle cables from the engines.
Push the helm throttle controls to max (engine NOT running).
Go to the engines and pull / push the engine throttle levers to full fuel (engine NOT running), vice grips may help.
Ensure the ends of the lever and cables are at the same place.

It is amazing how many times this proves cables have been messed with. Usually when someone tries to match the helm throttle control levers.

Yes. I'll try that tomorrow. Not as good, but easier, I could just throw the levers forward and see if the engine throttle lever is most of the way. I don't know why I don't think of this stuff faster.

I have gauges in the ER. I'll just push on the lever to see where 1,400 is...then turn them off and see how far the cables push 'em.

I have no idea the last time she got up on plane. That's the thing with a cheaply bought restoration - you have to assume everything is broken.
I haven't touched the sync, but something tells me I'll have to get to know it well very soon.

[MadHatter53]

I’m in on problem with the synch. It’s the common denominator.

[JuiceClark]

I have a question about the synchronizer. When going through the switches on the helm, I noticed that pull switch has two stops. Just like the navigation lights, it pulls out to two different positions. Why?

I've only had electronic sync on an electronic throttle before. (MicroCommander) It was either on or off. I can't imagine why the switch has two positions.


BTW - from a previous post, yes the throttles are hydraulic and not electronic.