Won't go on plane

[senkosam]

When I push the throttle forward to halfway, it doesn't continue to go faster to go on plane but only plows water with the bow high. When I bought the boat recently and took it out for the first time it did great, 40 hp withstanding. Seem like a fuel-starved carb.
Any ideas?

 

[GYPSY400]

Change the fuel hose from tank to engine, or try a known good one.

Has the boat been sitting in the lake and is now full of rain water?

Has your gas can been sitting outside in the hot sun and/or rain?

 

[FuzzyGrub]

Is this a modern efi engine? If so, it can be running in a protect mode.

 

[airshot]

Need more info....motor info, boat info etc. Pics will also help!

 

[thill]

Does the alarm whistle/horn work? Might be in safe mode, but if the warning horn isn't working, you wouldn't know.

 

[senkosam]

Has the boat been sitting in the lake and is now full of rain water?
Parked on land near my garage.

Has your gas can been sitting outside in the hot sun and/or rain?
New unleaded gas - always from the pump.

Mercury 40hp efi 4-stroke.

pic will be added to edit plus other info

 

[airshot]

How big is the boat? Trim angle? Why only half throttle, what about full throttle? Way to many "?" to come up with an answer

 

[senkosam]

The throttle once pushed all the way forward from half way up, does not increase RPMs. Trim angle starts from all the way down and then is raised somewhat once boat speed increases out of the hole.

Motor: Aug 2007 40hp EFI 4-stroke
(didn't think they even made 4-stroke motos back then)

Boat: 16'

Rear livewell empty starting out, no front livewell)

6" hydrofoils are upward in angle but haven't been tried yet on this boat/motor since they were installed only this am. On my last bass boat, they were horizontal and longer and helped big time getting the 90hp up on plane fast.

 

[davidj65]

Is this a modern efi engine? If so, it can be running in a protect mode.

What is protect mode?

 

[FuzzyGrub]

What is protect mode?

Depending on the engine fault, engine will limit rpm. Most are limp home modes but have also heard of mid-rpm limiters.

 

[airshot]

If rpm does not increase when full throttle then you have an engine problem...unless your boat is full of water!

 

[senkosam]

If rpm does not increase when full throttle then you have an engine problem...unless your boat is full of water!

Agree which is why I'm waiting for my mechanic to fix this sooner than later. I screwed up somehow in heavy weeds and won't do that again.

 

[airshot]

Agree which us ,why I'm waiting for my mechanic to fix this sooner than later. I screwed up somehow in heavy weeds and won't do that again.

Life is full of lessons, just learn from them...

 

[Pappy]

When I push the throttle forward to halfway, it doesn't continue to go faster to go on plane but only plows water with the bow high. When I bought the boat recently and took it out for the first time it did great, 40 hp withstanding. Seem like a fuel-starved carb.
Any ideas?

Push the throttle all the way forward to plane the boat off then reduce throttle to a desired cruise speed. Shift weight around in the boat to help you plane the boat. No boat stays the same when transferred to a new owner. Weight and weight placement always gets shifted.
Let's try this before changing parts that may make no difference.

 

[mak41]

When I push the throttle forward to halfway, it doesn't continue to go faster to go on plane but only plows water with the bow high. When I bought the boat recently and took it out for the first time it did great, 40 hp withstanding. Seem like a fuel-starved carb.
Any ideas?

Pappy has it right. Try something different before going the expensive route. A friend had a short Boston Whaler (70's) and best i can recall, a 15hp Johnson. With the two of uskids and fishing gear, it wouldn't hit a plane until I was in the bow and he moved to the middle seat.

 

[senkosam]

Maybe I could try running to the front of the boat to see if it drops the bow and running back before it hits shore - but only if the water's calm.

(Just kid'n)

 

[mak41]

Maybe I could try running to the front of the boat to see if it drops the bow and running back before it hits shore - but only if the water's calm.

(Just kid'n)

Once my friend's whaler got up on top, he was able to throttle back a bit and he could move back but as I remember, I stayed up front.