Takes super long to get up on plane...

mikegmi2

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Jun 11, 2013
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Hi,

Have a 2007 Kayot Z201, with a Merc 5.0L (Serial 0W672003).

Sometimes the boat gets right up on plane (3-5 seconds), and other times it takes 20 seconds...with the same load, trim, passengers, everything, and other times it can take a minute or 2 before I can get full power from the engine.

Feels like the RPMs are low and the engine isn't reaching full power for some reason, then all of a sudden kicks in and she's up on plane like a champ. I'll slowly move the throttle all the way to WOT and the RPMs don't go up. Just kinda stays bogged down in low RPMs. Sometimes when I pull the throttle back a bit that's when it kicks in, RPMs shoot up, and gets me up on plane.

The boat is 20', open bow, rated for 9 passengers, and I usually have 6 or 7 on board.

I just bought the boat a couple weeks ago and the previous owner never used it, it has 60 hours on it now after I used it twice this summer. It came with 3/4 tank of old gas. I topped it off with fresh gas, but haven't used it enough to burn off all the old stuff yet.

Could it be old gas?

I'd say 1 out of 2 times it struggles to plane out...but other than that it runs perfectly.

It has a pretty new, great condition, 14 3/8 x 18, 4 blade SS prop.
 

alldodge

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Re: Takes super long to get up on plane...

Sounds like a fuel issue. Could be part old gas but since it does get on plane and runs fine I would start looking into fuel filter, fuel pump, carberator, and fuel line restriction. Have you replaced the fuel filter?
 

spdracr39

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Re: Takes super long to get up on plane...

Put in some fuel stabilizer and change the filter. If that doesn't do it remove the old gas.
 

mikegmi2

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Re: Takes super long to get up on plane...

Thanks for replies. I'll be sure to change the fuel filter ASAP. I'll also put in some stabilizer...will the stabilizer I use for my lawn mower gas work or is there marine fuel stabilizer?

I burned off a decent bit of the gas in my tank this weekend, so I'll dump stabilizer in then top off with fresh fuel.

Any other fuel additive or treatment I could add to fuel tank?
 

alldodge

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Re: Takes super long to get up on plane...

Start with what has been discussed and see how it does, if the issue persist we can look into something further
 
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Re: Takes super long to get up on plane...

Thanks for replies. I'll be sure to change the fuel filter ASAP. I'll also put in some stabilizer...will the stabilizer I use for my lawn mower gas work or is there marine fuel stabilizer?

I burned off a decent bit of the gas in my tank this weekend, so I'll dump stabilizer in then top off with fresh fuel.

Any other fuel additive or treatment I could add to fuel tank?

Adding stabilizer won't fix a "bad gas" problem, and don't add any more additives! You may have water in the fuel, so the best solution is to drain the tank. Second best is to top it up with premium gas, and cross your fingers :)
 

mikegmi2

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Re: Takes super long to get up on plane...

Here is what my cap looked like, I'm surprised I got any spark at all at my plugs:
null-11.jpg


Cleaned them off really good with a wire brush, and going to change the plugs tomorrow morning, then test drive it.

Didn't have the right size spark plug socket otherwise I would have changed them yesterday. I bet they're pretty bad.

I'm also betting the boat runs much better after I change the plugs and cleaned the cap really well.

I bet my WOT issue was due to not always running on all cylinders?

Then again, when I revved the engine in neutral it sounded normal...
 

mikegmi2

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Re: Takes super long to get up on plane...

One other question, what is the purpose of this black tab on the side of the cap?
null-12.jpg
 

alldodge

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Re: Takes super long to get up on plane...

A hose would go from it to the breather area of the carb, not a direct vacuum source like under the carb or connected to the manifold. It pulls a little air which would keep moisture from building up under the cap. Most the time you will find it just like it is without a hose on it which is also OK.
 

mikegmi2

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Re: Takes super long to get up on plane...

Ended up being the corosion on the cap and fouled out spark plugs. Changed the plugs out Saturday, took it out for a spin and it runs great now, thanks for the replies everyone.
 
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