Mercury High 5

[butlp]

Just a word of warning to anyone thinking of investing in a high priced Mercury prop, watch out!<br /><br />I ordered a new rig with 115 Optimax in the spring and told my dealer I wanted a High 5 prop. I had run the numbers through the Mercury prop sizing program on their web site and it specified a 20" pitch High 5. My dealer said another option was a 22" Laser II and I assumed the 22" was selected because he had experience of the motor/boat combination. I went with the High 5 and assumed that 22" was the correct pitch and the dealer did not question this when I placed the order with the rig.<br />The boat was a dog, struggled to pull 5000 rpm with one person in the boat.<br />I called the dealer and asked him to exchange the prop for a 20" but he informed me it was mine and could not be returned. In Canada, Mercury only has a few dealers that subscribe to the "Prop exchange" program which allows you to test the prop before you purchase it. I contacted Mercury Canada and they told me to put the 22" on ebay and hopefully I'd get 50 cent on the dollar.<br />To cut a long story short; after a lot of finger pointing and me getting high blood pressure Mercury Canada agreed to exchange the 22 for a 20 as long as the prop was in perfect shape.<br />The 20" is a lot better but still only turns at 5200 rpm and is not as quick out of the hole as I had hoped, plus it's the smallest High 5 available for my motor. Now I'm looking for a 17" or 18" Lasor II on ebay

 

[LubeDude]

Re: Mercury High 5

Sounds like your dealer isnt very well informed. The high five is a hole shot prop, you would have posably been better with the Lazer. Maybe your engine is mounted a little low and you can use the one you have. Your ventilation plate should be at least 1" above the bottom of the boat.<br /><br />Give us the details about your boat, also, give us the #s you are running now. Do you have ventilation holes in your prop, I think all the high fives have them though. You could drill them or make them slightly bigger.

 

[butlp]

Re: Mercury High 5

The plastic ventilation plugs are still installed in the prop and I should pull them before doing anything else.<br />The boat is a 16'-6" bowrider (1100lbs) and the motor is a 2005 115 Optimax (WOT 5000 - 5750). According to the boat instrumentation, with one person, half a tank of gas and normal gear the WOT is 5200 and speed is 49 to 50 mph.<br />My problem is that the boat does not come out of the hole as well as my old boat with an old 90 Yamaha. When you buy a new boat you expect better performance than the old package. The dealer did water test the boat before I picked it up and he felt it ran well, however he told me the tach was not functioning properly and had shown 10,000 rpm during the water trial.<br />The motor now has approx 60hrs + and has been fantastic, very frugal on gas and oil, no smoke and very quite.

 

[LubeDude]

Re: Mercury High 5

We have all of the information we need except the hight of the engine on the transom. Put the engine in a level with the bottom of the boat position and look to see where the ventilation plate is to the bottom of the boat. Its likely slightly below or even with the bottom. It can be raised to at least 1 inch and maybe as much as 2 inchs from the bottom. This will give you 2-300 RPM more at WOT. That with the removal of the plugs may put you right in the ball park. Is your WOT RPM figure with the engine trimmed out all the way?

 

[WillyBWright]

Re: Mercury High 5

You seem to make the erroneous assumption that a SS prop is a SS prop is a SS prop. Each design has it's strong and weak points. And to kvetch so fervently without doing even the least bit of experimentation with those vent plugs means you need to do a lot more trying and a lot less complaining.<br /><br />3-blade props need to stay completely submerged. 4 and 5-blade props can pierce the surface of the water and still stay hooked-up. That allows you to lift the motor higher on the transom. That means less gearcase in the water. Less drag. More speed.<br /><br />It's not likely the wrong prop that's your problem. It's the set-up of the motor.

 

[walleyehed]

Re: Mercury High 5

I will agree the set-up needs attention...I do not agree that a 3 blade prop should stay under the water...<br />It all depends on the cup, Rake, etc.. run the prop where it performs best on that boat. I run my 3-blade Raker and Turbo about 3" out of the water...AV plate is about 4" above the water.<br />Another quick note...If you use the Merc prop finder, plan on 2" less pitch than what it recommends...I have not seen 1 single case where it was correct, ever.<br />22 in a 3-blade is not the same as a 22 in a 4-blade...nor is a 22 of a different manufacturer the same as a 22 Merc prop.

 

[butlp]

Re: Mercury High 5

WillyB,<br />I don't think I'm complaining but trying to warn other members that when it comes to Mercury SS props you're on your own, which I think is wrong. I'm not making erroneous assumptions about SS props, I realize they are different from alloy and SS 3/4 blades, the only assumption I made was that the dealer and Mercury Canada know which is the correct prop for my set up and if they don't then let me return it if it's incorrect!<br />If you had spent 25K on a new boat that was prepped for a Mercury O/B and supplied with a Mercury SS prop you would expect the motor hight and set-up to be right from the dealer, he's the expert If I had been told at the time of purchase if the prop was wrong it was mine to keep, I would have not spent the $500+ and stayed with the standard cheap alloy three blade. If you can find a dealer that will lend you a prop (they will never let you try the High 5) you're still guessing as the 5 blade is so different.<br />

It's not likely the wrong prop that's your problem. It's the set-up of the motor.

I don't have the equipment to raise a 400 lb motor on a brand new boat and the dealer and Mercury never suggested this as a fix or offered to help. They both said it was all my fault because I had specified a 22" pitch prop in my e-mail purchase order and I should live with it.<br /><br />LD, Walleyehed, Thanks for the constructive replies, I'm in Mexico this week but will be back at the lake next week and will measure the engine hight plus pull all the plastic plugs and report back.

 

[orca]

Re: Mercury High 5

I think your problem is not with your Motor or your prop, It is with your dealer.<br /><br />Every dealer that I have been involved with has been more than happy to exchange props. In fact most dealers will test run and make sure that the prop is correct before delivery<br /><br />Motor height is very important, the correct height for a 3 blade prop is probably not right for a 5 blade.<br /><br />Mercury have an interesting publication called 'Everything you need to know about propellers' that is worth getting hold of.<br /><br />It is up to the dealer to make sure that the motor is set at the correct height and has the correct prop.It is not up to Mercury to sort out the dealers problem, maybee they should be sorting out a problem dealer.

 

[LubeDude]

Re: Mercury High 5

Lostcanadian:<br /><br />We are going to make sure your experience with boating is a good one.<br /><br />First off, no boat, engine, or prop book on earth is going to nail your set-up perfectly, Its allways a crap shoot, but your dealer should step up to the plate and make sure your boat is right. Sounds like you made the recomendation instead of the dealer. Maybe you insisted on the highfive over what he offered, not sure, anyway, lets get it right for you, enjoy your trip, we will be here when ya return.<br /><br />Listen to Walleyehed, hes the prop guy along with Dhadley.

 

[moderator1]

Re: Mercury High 5

Moving to the new "Prop questions and Topics" forum in the General boating section...

 

[butlp]

Re: Mercury High 5

Whaley,<br />This is the third boat or motor I have purchased from this dealer and yes in the other two he was happy to exchange the standard alloy prop until I was entirely happy. In this case he said the High 5 was too expensive for him to stock and there was not a great demand for a 22" pitch so it had been special ordered.<br />He did test run the boat the day I came to pick it up and said it really performed, 50+ mph however there had been a problem with the tach and it was reading really high so he was unable to see what the WOT was at the lake. If I had been thinking I should have asked him to put the diagnostic tool on to see what the computer memory had recorded. It took me a few days until I fully broke-in the motor and could run it at WOT and then realized it was less than 5000 RPM.<br />Technically if I had stayed with the 22" prop my warranty could have been void as it clearly states that the motor must reach the minimum WOT and its the owners responsibility to make sure the correct prop is used.<br />From what the other guys are saying, it sounds like the 20" pitch I now have is probably the right prop and with a little work I may be able to get the hole-shot I'm looking for.<br /><br />If the motor hight looks low, what is the procedure to raise it? <br />Do you just unbolt and lift up to the next hole on the transom bracket?<br />There will be a gap between the top of the transom and the underside of the motor transom bracket, do I need to put a filler piece in?<br />I'm going to talk with the dealer and see if he will do it.<br /><br />Thanks all for your help!

 

[LubeDude]

Re: Mercury High 5

Originally posted by Lost Canadian:<br /> If the motor hight looks low, what is the procedure to raise it? <br />Do you just unbolt and lift up to the next hole on the transom bracket?<br />There will be a gap between the top of the transom and the underside of the motor transom bracket, do I need to put a filler piece in?<br />I'm going to talk with the dealer and see if he will do it.<br /><br />Thanks all for your help!

First of all we need to know where it is now.<br /><br />Raising the engine, if the dealer wont do it is a piece of cake, you can use your trailer support jack if you have one. Lower the trailer jack a bit, place a block of wood under the skeg and wind the trailer jack up untill it touches it. Then losen the nuts at the bottom of the mounting braket and remove the ones at the top. crank the trailer jack up untill the engine is where you want it and install and tighten the bolts with sealant, you are done. Takes less than an hour. Helps to have a buddy around to watch for you and steady the engine. Not necesary to put anything between the engine and the transom.

 

[butlp]

Re: Mercury High 5

Just returned (by road) from the lake and can provide the following information on the set-up.<br />The motor plate is about 1 inch above the bottom of the boat.<br />I removed the plastic plugs and the difference was incredible. The hole shot really improved as the motor immediately spun up to 5000+ rpm and then started to bite and the boat set off like a rocket. I think its cavitating a little too much so I have ordered a couple of different sets of plugs and will experiment next year.<br />Not sure if it was the cooler weather but without the plugs and trimmed out the WOT was 5500 to 5600 which is much better and totally acceptable.

 

[LubeDude]

Re: Mercury High 5

Thats great, I dont have the plugs in mine either, but I dont get quite the RPM you do at the first. Isnt it amazing how much difference those holes make???<br /><br />You might want to try raising the engine at least one more hole. Your engine can run another 2-300 RPM with no problem.<br /><br />"Now I'm looking for a 17" or 18" Lasor II on ebay".<br /><br />You are going to want to go up in pitch, not down, usually 1-200 RPM every loss of a blade. So maybe a 24 in a four blade and 25-26P in a three, espesially if you raise your engine.

 

[butlp]

Re: Mercury High 5

LD,<br />Are you sure I want to go up? That will reduce the WOT rpm, plus deteriate the hole-shot.

 

[LubeDude]

Re: Mercury High 5

Yes, you gain RPM when you drop a blade. My High five is a 25P but a small diameter, WOT RPM is 5,700-5,8000. My 4 blade is a 25P also, but a much larger diameter (15") and much more aggresive and dropped my WOT RPM about 300RPMs. Also lost some hole shot, but is about 3 MPH faster than the High Five. If I would have stayed with the same diameter as the High five I would have gained about the same amount of WOT RPM, probably would have put me at about 6,000 at WOT. Im going to try a 15 1/4 X 26 in a three blade shortly. My engine is quite high, Im just on the verge of losing water preasure at full trim. Thats why I can throw such a rooster tail when I want to show off. By the way, you wont find a better rooster tail prop than that High five when you get your engine raised. My Avitar is with the High Five.

 

[butlp]

Re: Mercury High 5

My goal all along with this rig is to have a good ski rig. Top speed is not the most important thing as long as my boat is faster than my two brother-in-laws and quite frankly that's not too difficult. I don't want to get to a point where I might loose water pressure (which is why my dealer is reluctant to raise the motor any more) as I'm still under warranty.<br />I think I'm pretty close with the 20p High Five, just need to play with the size of hole in the plastic plugs.<br />Remember I did have the 22p High Five to start with and the boat was a dog out of the hole and even though the indicated top speed was slightly higher than it is now the WOT was 4900 - 5000 at best.

 

[imported_bjs]

Re: Mercury High 5

i have a17 ft triton bass boat it has a 24 pitch laser 2 3 blade prop 120 force it will turn way over max rpm.the say diameter does not matter.but i dont know.iknow the prop that came with the boat was 23 pitch.the boat handles o lot better with the 24 pitch prop.

 

[LubeDude]

Re: Mercury High 5

You cant beat the high five for pulling power, Id just stick with it if I were you.

 

[gatorred]

Re: Mercury High 5

now i read this and understood 3 blade needs more water then a 4 or 5 blade prop if all are SS is this right