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View Full Version : Top speed, cutting out or hesitation


nrojay
08-01-2012, 10:59 AM
First post here.
I am the proud owner of a 95 Prostar 190 LT1

I just picked the boat up last week, I have had the boat out now twice.
The problem is when I run the boat at full speed Iím only getting up to 38mph, the boat will almost surge like its hesitating, the engine will act like it wants to open on up but will not.
I owned another Prostar 88 model it would top out around 45-48 and it had a 351 in it.

I have ran a bottle of b-12 and took it out last night still doing same thing.
Out of the hole it seems to be just perfect.

I would appreciate any help or suggestions

Matt@semmergroup.com
08-01-2012, 11:07 AM
Rev limiter kicking in? What RPM is it happening. A different prop might give higher speed at lower RPM.

Stx221
08-01-2012, 11:07 AM
Having had similar, but not identical problems after I bought my '95 Prostar (LT1/Powerslot), what do your gauges read when this happens? Oil pressure, voltage, and water temp are what I am referring to.

I have created a whole thread that documented the process of my boat ownership and research into my issue. Feel free to waste an afternoon and read that here: http://www.mastercraft.com/teamtalk/showthread.php?t=45389

Matt, I dont know that I've ever hit a rev limiter (as in a car rev limiter) in mine, it just doesn't rev any higher than 5200rpm. I have the 14x18 prop that came standard with the Powerslot.

nrojay
08-01-2012, 03:23 PM
what mph are you hitting

LYNRDSKYNRD
08-01-2012, 03:46 PM
The problem is when I run the boat at full speed Iím only getting up to 38mph, the boat will almost surge like its hesitating, the engine will act like it wants to open on up but will not.


Here ya go

thatsmrmastercraft
08-01-2012, 03:49 PM
I would start by going through all the basics: plugs, cap & rotor, wires, fuel filter, check timing and clean flame arrestor for starters.

JimN
08-01-2012, 04:02 PM
I would start by going through all the basics: plugs, cap & rotor, wires, fuel filter, check timing and clean flame arrestor for starters.

It has the LT-1, as he posted. No cap or rotor.

JimN
08-01-2012, 04:04 PM
First post here.
I am the proud owner of a 95 Prostar 190 LT1

I just picked the boat up last week, I have had the boat out now twice.
The problem is when I run the boat at full speed Iím only getting up to 38mph, the boat will almost surge like its hesitating, the engine will act like it wants to open on up but will not.
I owned another Prostar 88 model it would top out around 45-48 and it had a 351 in it.

I have ran a bottle of b-12 and took it out last night still doing same thing.
Out of the hole it seems to be just perfect.

I would appreciate any help or suggestions

ANY time a performance issue shows up, ALWAYS check the fuel pressure. This should be done at Key ON/Engine OFF, idle, 2000 RPM and WOT. Also have someone watch hte pressure as you go from low RPM to high RPM.

thatsmrmastercraft
08-01-2012, 04:05 PM
It has the LT-1, as he posted. No cap or rotor.

I guess I was on auto-pilot while I was hitting the basics:confused::D

Stx221
08-01-2012, 04:30 PM
As JimN stated and it shows in my thread, fuel pressure is the first step to diagnosis. I was able to find that voltage to my fuel pump was systematically being cut and pressure was dropping to zero and back to 42+ psi. This led to me to correct path of finding the problem.

I'd start with fuel pressure as well as letting us know what the gauges (temp, oil pressure and voltage) are reading when this happens.

SkiDog
08-01-2012, 04:40 PM
replace the damn fuel line from the tank! Ethanol gas is the problem! Its eaten up the interior of the fuel line. Happened to my 190. Replaced the line and that remedied the problem!

nrojay
08-01-2012, 06:15 PM
the temp never got above 120 even when pulling tubes hard and such, I just read stx221 whole thread wow you may be my "brother from another mother"
so yours ended up being the oil presure sending unit ?

nrojay
08-01-2012, 06:21 PM
one thing i did notice when test driving the boat was the fuel gguage would go from 3/4 full to zero then back to 3/4 like it was loosing connection but i checked the connections and all was good

LYNRDSKYNRD
08-01-2012, 06:25 PM
one thing i did notice when test driving the boat was the fuel gguage would go from 3/4 full to zero then back to 3/4 like it was loosing connection but i checked the connections and all was good

Ground may be bad even if the connection is tight.

Todd X14
08-01-2012, 09:29 PM
replace the damn fuel line from the tank! Ethanol gas is the problem! Its eaten up the interior of the fuel line. Happened to my 190. Replaced the line and that remedied the problem!

95% of all problems today in automobiles are fuel related.....Ethanol is the root cause. It eats things and what it cant eat... it coats.

Stx221
08-01-2012, 09:41 PM
the temp never got above 120 even when pulling tubes hard and such, I just read stx221 whole thread wow you may be my "brother from another mother"
so yours ended up being the oil presure sending unit ?

I think we need to see a picture of that Prostar of yours!

Yes, my issue ended up being the Oil Pressure Sending Unit. Once I swapped that out, all has been good. (Knock on wood!)

Brian B
08-01-2012, 10:33 PM
Northstar ignition?

My LTR did this. Bilge water would splash the coils. Pulled coils off, cleaned all connections, smothered connections in dielectric grease, problem solved.

thatsmrmastercraft
08-02-2012, 12:09 AM
Northstar ignition?

My LTR did this. Bilge water would splash the coils. Pulled coils off, cleaned all connections, smothered connections in dielectric grease, problem solved.

Nice fix. Gotta love dielectric grease.

nrojay
08-02-2012, 01:08 AM
wow!
Guess what I found, while doing some thurough cleaning, (Stx221 we may be kinned) , I pulled the rear seat out and there laid a silver steel box the length and height of the whole rear seat I opened the top and in it was 10 steel plates. I took one out after prying and several choice words was able to get one of them out, I took and weighed one of the plates 100lbs according to the bathroom scale, so I pulled all ten out, then I crawled into the front of the bow and yes there was a bag full of lead bb's I strugled to get it out and weighed it in at 150lbs.

A total of 1,150lbs of added weight, DO YOU THINK THIS MAY BE WHY IT WOULD NOT RUN OUT???? It sure should be alot easier pulling it to and from. I cannot wait to hit the lake Friday, I will report back..

nrojay
08-03-2012, 05:09 PM
what do you think would this much weight have any bearing on top speed?

carlsonwa
08-03-2012, 05:16 PM
My guess, is you are hitting your rev limiter. Compare you RPM when it is surging to the manual for your engine. I experienced this when I pick up a new prop last year. Had to have it cupped a bit more by OJ.

JimN
08-03-2012, 06:12 PM
what do you think would this much weight have any bearing on top speed?

Boat hulls aren't efficient when it comes to the thrust from the prop, meaning, it takes a lot to get it to move horizontally because of the drag on the wetted surface. When a boat is on plane, not much of the hull is in contact with the water and that means it can accelerate a lot faster. When the hull is displacing more water due to added weight, it takes a lot more to get it on plane. Also, since the prop is pushing against water, which moves out of the way pretty readily, it's a balancing act WRT selecting the correct prop. If the prop is too aggressive, the engine will bog under load and if it's not aggressive enough, it will cavitate. Even at speed, the water is trying very hard to slow the boat, so you won't reach the typical top speed for this boat unless you add a lot of power and prop.

nrojay
08-04-2012, 10:55 PM
Ok just pulled into drive after an awesome 8 hours on the water in Broken Bow, OK
The weight was the problem it ran out at 48mph GPS. However it still kinda surged a little at top speed like a horse trying to run back to the barn. I will clean the fuel screen and change fuel filters this week. WOW I LOVE MY BOAT !!

JimN
08-04-2012, 11:56 PM
Ok just pulled into drive after an awesome 8 hours on the water in Broken Bow, OK
The weight was the problem it ran out at 48mph GPS. However it still kinda surged a little at top speed like a horse trying to run back to the barn. I will clean the fuel screen and change fuel filters this week. WOW I LOVE MY BOAT !!

What is the temperature after it has been running for a while? If it's still 120į, you need to address that. If that's as high as it gets, I would guess that at least one of the thermostats was removed and that's not the way this engine was designed to be run. It also wastes a lot of gas because a cold engine is never efficient You can't possibly burn all of the fuel being delivered at that temperature. Best practice is to connect it to a diagnostic computer and see the info that's going to the ECM, not the gauge on the dash.

nrojay
08-05-2012, 12:41 AM
it was running at 160 all day long

FrankSchwab
08-05-2012, 01:50 AM
What RPM are you at when the engine is surging?

With 1150 pounds of steel and lead in the boat, it's likely the previous owner put a prop on the boat designed for wakeboard speeds, which means that you'll hit the rev limiter when going fast. You can choose to either pull the throttle back a bit to keep the engine off the rev limit, or buy a new prop that will keep the engine from hitting the rev limiter.

/frank

nrojay
08-05-2012, 05:14 PM
You know I think ill just hold back on throttle for now, I can barefoot, slalom, wakeboard, kneeboard and tube just fine like it is and look for a deal on a prop in the future.

This hull design is awesome on slalom virtually no wake before removing all the steel, I was plowing hard into the wake.

Good news is Steel prices are good I can sell this steel and maybe put a good bit on a new prop!! :D

cptskier15
08-06-2012, 06:39 AM
Read the whole thread and not a single photo of the boat :P

Stx221
08-06-2012, 12:59 PM
Read the whole thread and not a single photo of the boat :P

It's sad, really. He has 9 posts and no pictures! We don't even know the color scheme of the gelcoat... Hopefully he changes that.
:D

nrojay
08-06-2012, 02:00 PM
ok if someone will explain how to post a picture ill do it

nrojay
08-06-2012, 02:06 PM
http://www.mastercraft.com/teamtalk/album.php?albumid=731&pictureid=4319[/IMG]

thatsmrmastercraft
08-06-2012, 02:07 PM
ok if someone will explain how to post a picture ill do it

This is one way.


1. Click Paperclip icon
2. Click Browse button
3. Locate the picture in your computer and click on it
4. Click Upload button ( to the right of the Browse button)
5. Once picture is uploaded (it will take a moment or two) it will show as Current Attachment
6. Click Close Window button
7. After you have entered text, use Preview Post button to make sure you selected the proper picture.

nrojay
08-06-2012, 02:57 PM
ok here goes

thatsmrmastercraft
08-06-2012, 04:01 PM
ok here goes

Nice looking ride. Any more pics?

LYNRDSKYNRD
08-06-2012, 04:34 PM
Sweet ride nrojay! I love the color combo and your tower too! What brand is the tower?

cptskier15
08-06-2012, 05:40 PM
Wow that's a sweet boat!! Like the colour scheme!!

Stx221
08-06-2012, 10:13 PM
I'm digging the color scheme as well!

Good looking boat.