Me and my cuz have purchased a new boat triton 18x2. And we have a question on the motor. The motor is a mercury 175 pro xs and the question is it takes us about 12 seconds to get on plane and the top end is only 5100 rpms any help please. Also the pitch of the prop is 23.
Welcome to the BBC Robert !!
My first thought would be to check to see if the motor is going to full throttle; it may be that the linkage or the hot foot (assuming you have one), isn't set properly.
Is there a jackplate on the boat and what is the model of prop?
Me and my cuz took the boat back to the dealer and found out by hooking a computer an was informed that wot was only at 80% so they readjusted the hotfoot to about 97%. Then we went to lake conroe and there was only one slight difference is that take off went from 12 seconds to 8 seconds. The top end speed was on 54mph at 5200rpms so this didn't change at all. Any help please.
Wow. 97%? Why not 100%? Since your dealer didn't have the hotfoot installed right, I doubt the setup is anywhere near optimal. So let's check something...
First - is your prop a 3 bladed Tempest?
With the boat on the trailer, trim your motor down so that the cavitation plate (just above the prop on the lower unit) is parallel to an imaginary line that is extended back from the running surface (the very bottom) of your hull. Tell us how many inches your propshaft is below that imaginary line. Hold a straight edge against the bottom of your hull and measure from the front 'point' of the lower unit up to that straight edge.
Is this a new dealer?? I'm having serious doubts about their competence.
Congrats on the new rig! Post a picture of it!
We have played with the trim an get the same results. And we take off with the motor down an once on plane we trim up. Before they adjusted the hotfoot we noticed that wot screw wasn't touching were it was suppose to it was about an half inch off from touching and that seem right, an so the dealer adjusted the hootfoot with no changes. The prop is a tempest plus.
I'm not talking about trim - I'm wondering how low your motor is set on the transom. Sounds like your motor may be too low. If that's the case, you can raise your motor and gain rpm/speed at wide open throttle. But we need to know where your at right now. So:
Take a long straight edge, (long carpenter's level or long steel ruler, etc.), and place it on the bottom of the pad in the center. Tilt your motor until the bullet of the gearcase is parallel with the straight edge.
Measure from the top of the straight edge to the center of the front of the "bullet" on your lower unit. This will be the center of the propshaft. This measurement will tell us how many inches your propshaft is below the pad.
Regarding your prop - does it have any black plugs in the holes near the base of each blade? If so, removing these plugs, or installing plugs with larger holes, will help you get out of the hole faster. Once motor height is figured out, experiment with the plugs to find the best combination. Note - these plugs only affect your holehsot. They don't affect your top end at all.
We have tried removing the plugs 1 at a time with no change. How many inches should I be looking for?
Here's some measuring tips: http://www.bassboatcentral.com/measuring.htm
You would want the propshaft somewhere in the range of 3" below the pad.
sounds like motor is way too low,most 175 mercs are rigged with a 25 instead of a 23.you should raise the motor on the jackplate a good bit and see if ur rpms come up.if you get your motor hieght right you should be spinning that 23 thru the roof ,and your holeshot will be much better.classic signs of motor too low.keep raising it until rpms hit 58k and water pressure is 12 to 15 lbs trimmed out at wot. and put some plugs back in (with holes) they do affect top end if thay are all out, too much ventilation will drop speed even though your turning more rpms.
We also noticed that the water pressure was between 20 an 30 psi. Is this a little to high?
Water pressure Sounds Good. I would do a compression check on each cylider just to have peace of mind
what part of raise the motor is confusing you? 30 lb of water pressure is great, if your trying to achieve great water pressure. however if you want that boat to get up and run youve got to raise the motor to give it more rpms, thus dropping water pressure as the intakes are closer to the surface.as i stated before as long as you have 12/15 lbs minimum at wide open throttle trimmed all the way out, you are fine!it doesnt matter if pressure is higher than this, the issue is getting the motor high enough to spin the prop the desired # of rpms (5800) and then look to see if you have at least12/ 15 lbs press. now drop and give me twenty!
We went back to the dealer an exchanged the prop from 23 to a 21. Going out tomorrow and I will let you'll know how it went.
My cuz just checked the motor height an he measured 2 1/2 to 2 3/4". Looks like the motor is the right height.
Post your question on the Triton boat section of the forums. I'm sure you will find several people with identical rigs that can tell you exactly their setups... That said, I can't believe that a 21" pitch is right for a 175. They may have changed the ratio for the lower unit, but on all the older motors, you want to run at least a 25" at 5800 rpm. Your top end should be close to 70mph. I can do that with a 200 efi on a 99 TR20.
Rich
Hey there here are the results after changing prop pitch. Holeshot still sucks, rpms increased by 200(org.5200 now 5400), and mph went from around 55 to now 52. Any opinions?
Bassmaster1234
Yeah. Still the same one. I can't imagine a 21 (or even a 23) being right for that rig. I could be wrong (once or twice). Try Triton boat forum and/or try the "props" or "setup" forums. It surprises me that the dealer wouldn't know the right prop for that combo. Another thing you might try is the Triton web site and email or call their support people. They should be able to tell you the right setup. Every boat/motor is different, but not by the amount you are showing, unless something is drastically off.
One other thought. I think all mercury's have a plate on motor mount with the maximum RPM. I would guess 5800-6000 for a ProXS. You should be propped to run at just about that in cold weather. With the right prop and setup, that will be your max speed also. I would be surprised if that rig wouldn't run in the upper 60's minimum.
Rich
My 18 ft Stratos has a 25 prop. Holeshot and top end are good. Maybe try a 25 on your rig.
.
Neil Eckberg- Cary, NC - 2008 Skeeter ZX250- 250 Yamaha SHO
Kerr Lake Ba$$hole
the 150 efi on my 18' nitro is running a 25p, hole shot is good
'02 Gambler Outlaw
'02 Mercury 200 EFI 2.5L
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bassmaster1234 »</TD></TR><TR><TD CLASS="quote">Hey there here are the results after changing prop pitch. Holeshot still sucks, rpms increased by 200(org.5200 now 5400), and mph went from around 55 to now 52. Any opinions? </TD></TR></TABLE>
You either have a very sick motor, a water logged hull, both or you are just stubborn.
Take it to the dealer tell them you want to know the engine height from the pad I am guessing you are measuring wrong or that motor is roached..
I had a sick motor and was slinging a 23 pitch to 5k rpms on a 150 Ficht with a bad cylinder...
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