HELP Motor losing power? & Boat porpoising?

Ok so I need a bit of help with two issues.
1. the Motor a 130hp Johnson will lose all power sometimes while at top end speed. Seems like a fuel issue, so I plan on changing out the filter and perhaps the squeeze ball as well. any other suggestions?

2. Near or at top speed the boat will begin to porpois? I did get the fins for the motor and put them on. I also did lower the motor just a bit, helped some but not near enough. I was also told to look for a “hook” on the boat itself. I have not looked closely yet, if I understand what a hook is?
Both seem to be separate issues.

Thoughts or help on either would be appreciated!

What brand and model of boat do you have? Does it porpoise happen when your motor is completely trimmed all the way down?
Have you tried to redistribute the weight in the boat?

FDR

I had a Johnson 40 hp tiller that did the same thing as far as dying at top speed. I was informed to start with the fuel filter and squeeze ball, but don’t overlook checking ALL your fuel lines. Even a small crack or split too small to leak can cause this problem too.
Does your 130 re-start instantly or does it require ball manipulation first?

Fuel line is cheap, so I replaced all of it and my problem instantly ceased.

Your results may vary.

Good Luck.

I had something like this on my motor, check you spark plug connections and if you haven’t dne it recently, change them.

my 25 merc was acting the same way till finally had to look at it and found the fuel hose was collapsing inside had a linerin the hose could not see it from the out side—change hose and ball–snagged

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2. Near or at top speed the boat will begin to porpois? I did get the fins for the motor and put them on. I also did lower the motor just a bit, helped some but not near enough. I was also told to look for a “hook” on the boat itself. I have not looked closely yet, if I understand what a hook is?
Both seem to be separate issues.

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You may be able to correct this problem with a prop change. Going to a 4 blade prop will generally give you more bow lift. Most time this fixes hi end porposing proplems. Test out the new props without the fin.

-J.

Thanks for the info so far, I have redistributed the weight, moving 2 batteries up front. This changes little.
I am in the process of changing out much of the gas lines, plugs and already did the filter. WE will see what will happen.
Thanks and keep coming with the suggestions.

I’m betting the “hook” they’re talking about is at the edge of the hull where it contacts the transome, they add a bit of wedge to the seam and it causes the stern to lift and pushes the bow down.

Do not add a Hook to your hull until all other avenues have been tried.
I’d go to trim tabs before having that done.

Been there done it…not again, thank you kindly.

Al

Just to cover your bases, check your battery terminals and clean and tighten if necessary. My 115 used to cut out due to being very voltage sensitive-which was caused by corrosion on the battery terminals. It would intermittently cut out.
Your other issue seems to be prop related. Is your boat under horsepowered?

Your motor is a 130 with power trim right?

What model is your boat?

The boat is an 18″ Xpress, Aluminum, with 130hp being to top rated hp possible.
The boat will idle fine, even when it is powering down, boggin, at top speed.
The motor does have power trim.
I am in the midst of replacing the squeeze ball and fuel lines to it. I am also replacing the spark plugs.
Thanks

You probably have done this but I gotta ask. When the boat begins porposing can you trim motor down slightly and it rides smoothly? Any boat can porpose, but trimming should correct the problem.
When I reach planing speed I instantly trim my motor up until I begin proposing, then down slightly for max Rpms , speed and ride.

My $0.02

Yes I have done this. It goes beyond just a little trim adjustment. I knokw I am missing a significant amonut of top speep. have been able to get it correct a very few times and it is a significant difference.

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The boat is an 18″ Xpress, Aluminum,

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Is this a Modified V with flat bottom?

-J.

Another dumb-gotta-ask-question…..
Is your hull empty? I mean is there ant water from rain or anything else that is sloshing around in your hull or have you drained it?

Mod V.
Nope no water, it is filled with 3 batteries, 2 up front, and gear. I tried putting as much up front as possible. Even with a person up front it will still happen.

With a flat bottom boat I doubt there is anything you can do to stop the porposing. Full down trim and lay off the throttle.

-J.

I wish mine would porpoise. my 16 foot mod v xpress is only rated for a 30 tiller. I bet that thing goes like a raped ape with a 130 on it. I agree with John. That hull is a utility boat designed for duck hunting and gators. They are not designed for speed or comfort. You might check to see if your motor could be raised or lowered for ideal handling.