200 Merc doesn't want to get up on plane...

[Smib]

:(Hey guys I need some ideas please,

I've got a '97 Merc 200 EFI that hangs up at 3000-3100 RPM trying to get up on plane. Once the boat gets up on plane it runs outstanding .  It takes 30+/- seconds for the for the nose to come over and the boat to get up on plane.  I have changed the plugs and that is it so far.  I'm was thinking maybe fuel filter but then why would it run good at 5,000 RPM?  Or maybe the primer bulb cavitating but then again why does it run good at 5,000?

I would appreciate any ideas ya'll have.

Thanks,  Smib

[Gatorbassman]

Try sending a PM to spotaholic. His boat was doing the same thing about a month ago. He should be able to help a little.

[Ben]

Is this boat new to you?

The reason asking, has it always only turned 5,000 rpm at WOT?  If so, you are way the heck over proped.  That motor should be turning close to 6,000 with normal load at WOT.

If it was turning close to six and now only turn 5,000, you probably have a dead cylinder.  One not getting fuel or fire.  

If it is over proped, the problem is only going get worse as the air temps and water warms up.

[Smib]

Ben,

Thanks for the email.  I was just using 5,000 as a reference, she'll do more.  It has a  25 pitch- three bladed stainless prop.

Thanks again,

Smib

[Ben]

Sorry, but if you're talking about this Ben, I didn't sent any emails.  

[ga_hawghauler]

what size boat do you have this on and also do you have a jackplate installed.

[Smib]

It's a Basscat Pantera II with a manual jackplate.  I'm hoping it is the vent plugs in the prop.  I honestly had not known alot about them until getting some info on line.  I'm going to take a good look at the prop tonight.

Any ideas you have will be definitely appreciated.

I really do appreciate all that have offered info to me.  

Smib

[ibhawgman]

My 01 Mecury EFI 175 has the same problem. Once on plane.. the motor runs fine. I have had the boat and motor for three years and the problem just started. I replaced the fuel filter, the plugs are next. Any ideas would be helpful.

Thanks

[cart7t]

It's a Basscat Pantera II with a manual jackplate.  I'm hoping it is the vent plugs in the prop.  I honestly had not known alot about them until getting some info on line.  I'm going to take a good look at the prop tonight.

Any ideas you have will be definitely appreciated.

I really do appreciate all that have offered info to me.  

Smib

Did you just get this boat or have you had it awhile and it just started acting up like this?

The prop shouldn't be the problem. That 200 should have no problem turning that 25.  Have you tried plugs, fuel filter and especially the primer bulb?  Remember, that engines under a lot more load when you're trying to push the nose over vs running WOT up on plane.  

[Ben]

Can't offer much since I don't mess around on the dark side, don't know much about them black motors but he never did say what rpm it's turning at WOT. That 2.5 motor is not a real high torque motor and needs to be turning 5,800 - 6,000 at WOT. I don't care what kind of boat it's on, if it's only turning a little over 5,000, it ain't gonna come out of the hole strong.

If the rpm is up where is should be, could have a problem with high speed windings in stator, that's about where they start coming in.

I see too many people trying to run a taller props thinking that's gonna give them more speed, but the motor doesn't have the innerds to spin that prop at near max rpm, it's gonna actually run slower and be a dog coming out of the hole.

Another thing you might want to look at is running a compression test.  Low compression a a cylinder or two can cause your problem.  Compression makes torque, not horse power, so the motor can still run fine at WOT but be very slow getting on plane.  Again thought, that's ONLY if the motor is turning 6,000 rpm or dang near it'

[Smib]

Thanks ibhawgman, cart7 and ben,

I'm going to do the filter and primer bulb tonight--I changed the plugs already.  

If that doesn't fix it then I'll get the compression check done and have the coils and powerpack looked at.  I checked the prop last night and it is a 25 pitch Tempest with no vent plugs in it.

I've had the boat up to 5400 rpm doing 70 and I backed off of it.  My Astro fish and ski with it's 135 Merc was a just a little bit slower than this one.....haha

I've only had the boat for a month or so and have had it on the water 3 times--problem got worse each time, especiall this last time.

Thanks again for all the replys,

Smib

[Smib]

:)Thanks to all that offered advice.  I changed the fuel filter and primer bulb and she gets up on plane like a champ now.

Thanks again,

Smib

[Biglouie]

so we don't know if it was the bulb or the filter than?  Seems wierd the boat would run so well wide open if the filter or bulb was the problem?  Or maybe I just don't completely understand these beasts, which is probably the case. ;D

[George Welcome]

Didn't make sense: Sounded like the TPS - Throttle position sensor

Engine is designed with a 23P in mind - 25 is overpropped.

[Smib]

I ran her again at Choke Canyon Saturday and she ran great.  I changed the bulb and filter the same afternoon so I don't know which one was the fix.  I'm just glad it's a done deal.  Thanks again,    Smib