Boat having issues getting on pad

[Texasfishn]

I have a 1991 mercury 200 efi, on a 20’ skeeter. The boat will get up and get on pad no problem on the initial take off. Stop and fish for a bit, go to leave, it may get on pad it may not. Most of the times it will not, especially if I have to idle for any time before jumping on it. No excessive water or weight in the boat, motor runs fine, but this is getting old!

[Russ E]

Can you describe what it does? Sounds odd to me. Mostly if a 200 horse motor is running fine. 

You did not give much information, so we will start with the obvious.

Is the motor trimmed all the way down every time you take off?

If you try to take off with the motor up, you will plow water and push the bow up in the air.

 

 

[A-Jay]

7 hours ago, Texasfishn said:

I have a 1991 mercury 200 efi, on a 20’ skeeter. The boat will get up and get on pad no problem on the initial take off. Stop and fish for a bit, go to leave, it may get on pad it may not. Most of the times it will not, especially if I have to idle for any time before jumping on it. No excessive water or weight in the boat, motor runs fine, but this is getting old!

Hello and Welcome to Bass Resources ~

 Sorry to hear your rig is not performing as you would likecouple of questions for you:  how experienced of a boat operator are you ?

What is your motor's rpms at wot and are you able to reach them now ?  

Does your motor have trim capacity and do you know how to use it ?  

Have you recent hit the bottom or other wise damaged the motor skeg and or prop ?

  Have you recently replaced your prop ?  

Answers to these may help get you headed in the roght direction. 

A-Jay 

[Texasfishn]

1 hour ago, A-Jay said:

Hello and Welcome to Bass Resources ~

 Sorry to hear your rig is not performing as you would likecouple of questions for you:  how experienced of a boat operator are you ?

What is your motor's rpms at wot and are you able to reach them now ?  

Does your motor have trim capacity and do you know how to use it ?  

Have you recent hit the bottom or other wise damaged the motor skeg and or prop ?

  Have you recently replaced your prop ?  

Answers to these may help get you headed in the roght direction. 

A-Jay 

-New lower unit, not damaged at all. -WOT RPM around 5300. 

-Trim works great. 

-I am beginning to think a diaphragm in my fuel pump could be causing this issue. Letting excessive amounts of fuel by after the fuel system is pressured from cranking. 

After my first run, or If I stop and graph I can’t get above 7 mph to take off. Occasionally, if I catch a wave right it will get back up on pad, but it just bogs really bad. First run is always great, comes out of the hole, hits top speed and runs like a dream, it’s just after it’s run or idled a time, it acts up. 

[A-Jay]

8 hours ago, Texasfishn said:

-New lower unit, not damaged at all. -WOT RPM around 5300. 

-Trim works great. 

-I am beginning to think a diaphragm in my fuel pump could be causing this issue. Letting excessive amounts of fuel by after the fuel system is pressured from cranking. 

After my first run, or If I stop and graph I can’t get above 7 mph to take off. Occasionally, if I catch a wave right it will get back up on pad, but it just bogs really bad. First run is always great, comes out of the hole, hits top speed and runs like a dream, it’s just after it’s run or idled a time, it acts up. 

Got it.

@Way2slow may be able to offer some ideas here, he's done so in the past here.

Seems past my most basic diagnostic abolities.

Either way hope you can get this resolved soon.  

A-Jay 

 

 

 

[bagofdonuts]

I think I remember there being some design issue with the early efi motors, that would cause air to get in the fuel line, and it would happen after the initial run. I think it was a fuel temp issue. 

[WRB]

So what is changing between initial cool engine run with adequate power and warm engine run with power loss?

The 1st thing that pops into mind is adding weight by filling the livewells, 30 gallons of is 240 lbs in the rear of the baiting that impacts hole shot getting onto plane.

The 2nd thought is over heating, bad thermostat.

3rd would be cracked cyclinder sleeve or head gasket, compression check all the cyclinders.

4th prime bulb /fuel line supply issues starving the engine.

5, 5300 WOT seems about 400-500 rpm low for a '91 Merc EFI engine, that could be due to weight balance in the boat or too much prop pitch or both. What is the speed at WOT?

Hope this helps somewhat.

Tom 

 

[Texasfishn]

4 hours ago, bagofdonuts said:

I think I remember there being some design issue with the early efi motors, that would cause air to get in the fuel line, and it would happen after the initial run. I think it was a fuel temp issue. 

Hmmmm that sounds expensive 

1 hour ago, WRB said:

So what is changing between initial cool engine run with adequate power and warm engine run with power loss?

The 1st thing that pops into mind is adding weight by filling the livewells, 30 gallons of is 240 lbs in the rear of the baiting that impacts hole shot getting onto plane.

The 2nd thought is over heating, bad thermostat.

3rd would be cracked cyclinder sleeve or head gasket, compression check all the cyclinders.

4th prime bulb /fuel line supply issues starving the engine.

5, 5300 WOT seems about 400-500 rpm low for a '91 Merc EFI engine, that could be due to weight balance in the boat or too much prop pitch or both. What is the speed at WOT?

Hope this helps somewhat.

Tom 

 

I keep the live wells closed because I thought that was the issue, it could be overheating, but I have put new controls in the boat and the alarm does not go off (except when gas or oil is low). I agree about the low rpms, but I have not changed the prop since owning the boat and they have always been that speed. Max speed is around 53 mph. Last compression test I did a few months weeks ago was fine. I will run another compression test in a few hours and see where that takes us. 

 

It has a 24 pitch 4 blade prop on it that has been on it forever. I am thinking about moving to a 23 pitch 3 blade, but that I feel would not fix my issue, just help my boat move with the issue. 

 

I have and changed all of the fuel lines in the past off season to black fuel hose rather than the grey, it ran amazing right after that. 

Thanks for all the help from everyone. 

[WRB]

Have you always ran in the mid to low 50's? Your hull w/200 Merc should run the mid to high 60's!

Tom

[gnappi]

I think Tom's fuel supply descriptions are worth looking at. 

 

Have you tried squeezing the primer bulb when you think you will next have the problem? 

 

 

[fishnkamp]

This may seem to be stupid, but if you replaced the, Merc primer bulb with either an after market primer bulb or another factory primer bulb that may be your issue. I know you just replaced the fuel lines so maybe you replaced the primer bulb too. I have troublshot several boats and found issues with the factory brand new primer bulbs and fixed it by using only johnson evinrude primer bulbs.  I even had a bad one on my Lowe bass boat right from brand new.

 

[MickD]

You said "diaphragm pump?"  If you have a 1991 with its original diaphragm pump, that is where I would start to look. A diaphragm pump for anything that is critical is a design mistake, iMHO.  They fail from use.  They fail from age.  They just fail.  You may not be getting enough fuel.

[Texasfishn]

4 hours ago, WRB said:

Have you always ran in the mid to low 50's? Your hull w/200 Merc should run the mid to high 60's!

Tom

Yes, unfortunately, 54.7 is the fastest I’ve ever got it up to on slick water and low gear. 

2 hours ago, fishnkamp said:

This may seem to be stupid, but if you replaced the, Merc primer bulb with either an after market primer bulb or another factory primer bulb that may be your issue. I know you just replaced the fuel lines so maybe you replaced the primer bulb too. I have troublshot several boats and found issues with the factory brand new primer bulbs and fixed it by using only johnson evinrude primer bulbs.  I even had a bad one on my Lowe bass boat right from brand new.

 

I can’t remember if I changed the primer bulb or not. I’ve slept since then hahaha. I will check that out. Do the primer bulbs have a filter in them by chance

2 hours ago, gnappi said:

I think Tom's fuel supply descriptions are worth looking at. 

 

Have you tried squeezing the primer bulb when you think you will next have the problem? 

 

 

Yes sir. I actually tried that for the first time last night when I was out, no change. I ended up having to jam lure boxes on my hot shot to hold it down and stand on the front deck to get it to nose down. NOT MY IDEA OF A GOOD IDEA!!!!

11 hours ago, A-Jay said:

Got it.

@Way2slow may be able to offer some ideas here, he's done so in the past here.

Seems past my most basic diagnostic abolities.

Either way hope you can get this resolved soon.  

A-Jay 

 

 

 

Thanks aJay. 

I ordered a rebuild kit for my pump. The only other mechanical issue I could see being the cause (mind you I’m not an outboard expert and am asking for help for a reason) is a bad temp sensor. That would make sense to me also. Telling the motor it’s cold and not adjusting the choke. 

[WRB]

What prop are you running? It sounds to me you are over propped and any drop,in power is like dragging an anchor. 

The prime bulb doesn't have a filter, it does have a check ball and made of rubber can get cracks or pin holes that suck in air. Easy to change out.

Tom

 

[Way2slow]

When the first sentence start of saying Mercury usually don't even read the rest.

 

My thoughts on the issue is the motor is terribly under powered or the prop is way too large. 

If it were mine, I wouldn't be comfortable with anything less than 5,800 rpm with my normal load. 

Fuel starvation usually causes a surge, it's not common for one to turn a steady RPM when starving for fuel.

To keep in simple, first thing I would do would be a plug dump.  That's shutting the motor off while holding WOT, after running WOT for about five minutes, running down the lake of course.  Cut if off while heading toward the ramp and use TM, do not restart motor until plugs have been look at.  All six should be even in color and depending on how good you EFI computer is, the can be almost white to paper bag brown.  The key is ALL SIX should look identical, then you are trouble shooting something that affects all six cylinders but if, some light and some dark means things are not right somewhere.  Too light is too lean, vacuum leak or something.  Too dark, means too rich, low compression, bad plug, plug wire, coil, ignition etc.   Run it on the hose or in a tank for about 10 minutes to warm up good, then do a leak down or compression test.

 

One thing, don't assume your prop is good until you've tried a different one.  I've seen props with a rolled edge that looked perfect to the naked eye.

[WRB]

Agree, I think the prop has always been too much pitch if this set up only run mid 50's!

I would start, after checking the plugs as suggested, with trial/loaner Tempest SST 3 blade Merc prop 1" lower pitch; ie 26 go to 25 for example to run 5800 rpm in the mid to high 60's.

Tom

[Way2slow]

I don't have any experience with a 20' Skeeter, but have modified 3.0 OMC 200's on three Stratos 201's from the mid 90's.  With a stock 200hp Johnson these boats ran between 58 and 61mph max with full tournament load and two people.  I would think a 20' Skeeter would do about the same. 

 

Also, understand you could possibly have hull issues that could cause the boat to have slowed down and loading the motor more if it used to run faster at higher RPM.  I've seen several boats that the trailer was not adjusted properly to fit the hull and over the years cause terrible distortions, hooks, and bows in the hull.  I even owned one of those.  That's when you need someone with the know how to check and blue print the hull.  Notice, I said with the know how, some hull can be ruined by doing what one thinks looks good but it's not.  I had a friend that thought he would blue print his Allison, which has a built in hook, and he took it out, totally the wrong thing to do.  I spent a week reshaping his hull with fiberglass, body filler and a lot of sanding, to get it back to the way it was designed to be.

There is a host of things that can cause a boat to loose RPM and speed, it all just a person with the skills going through the process of elimination to get it right.   Those 201's I referred to, they went from the 60 mph to almost 80 when done with motor and setup, and still wearing those 200hp decals on the motor.  Not bad for one of those old lead sleds.

 

 

[WRB]

Skeeter bass boats changed from glassed over wood transum and stringers in the early 90's, it's possible this '91 20(DX?) has wooden transum that has dry rot. Most Skeeters came with Yamaha engines in that era. I owned '88 SF175 Skeeter w/175 Merc that ran 70+ with 2 and tackle, same shape hull, 18" shorter. 

You mentioned a Hot Foot, does this hull also have a jack plate and after market trim kit? Lots of things to consider. Put a straight edge on the plane pad surface, it should be flat, no day light.

Let us know what the problem is.

Tom

[James D.G]

I didn’t read everyone’s post so someone may have covered it, but I have had 2 motors do about what you are talking about, one was a 1988 Yamaha, oil injected , unit was over oiling at certain positions on the throttle, 2nd was 1987 mercury, it would run like a scalded dog on the first run, then like you said when you go to take off again, it would bog down. Same if you idled a little while, I started have to rev the engine for a minute or 2 , to burn off excessive fuel or oil ? After that it would get up and run again .  On the Yamaha I disconnected Oiler and started mixing oil in gas, the mercury I ever pin pointed it, I would just rev it up for a bit when I went to go again, pretty sure it was carburetor related though. 

[Texasfishn]

Update:

For starters, thanks to everyone for the wonderful, friendly advise. As a long time view of these forums, and a first time user, I am very impressed. 

 

I got got the new diaphragm installed and just took the boat out for a test run. I took off from the ramp, no issues, I ran around for 5 minutes then hauled back towards the ramp, shut it off and dinked around a bit, fired it up and took off like a dream. Ran to the other end of the lake, fished a bit, boat took off fine. 

 

I gained a few mph, which is secondary to the motor now sounds soooo much smoother. 

 

Thanks again guys. 

[A-Jay]

9 minutes ago, Texasfishn said:

Update:

For starters, thanks to everyone for the wonderful, friendly advise. As a long time view of these forums, and a first time user, I am very impressed. 

 

I got got the new diaphragm installed and just took the boat out for a test run. I took off from the ramp, no issues, I ran around for 5 minutes then hauled back towards the ramp, shut it off and dinked around a bit, fired it up and took off like a dream. Ran to the other end of the lake, fished a bit, boat took off fine. 

 

I gained a few mph, which is secondary to the motor now sounds soooo much smoother. 

 

Thanks again guys. 

Cool.

Congrats

A-Jay