Smart Tabs / Prop Selection

R

robbo8199

New Member
Aug 3, 2010
59
Houston
Boat Info
1995 Sea Ray 175
Engines
Mercruiser 3.0LX Alpha One
I have a 1995 175 and getting up on plane takes a while. The entire boat is only 2100 pounds dry and it feels like about 95% of that weight is in the back with the engine and fuel. If I have a full crew for the day I am constantly asking someone to move up to the bow to help get on plane.

I have read nothing but great things about Smart Tabs and I plan to add them as soon as I can. The bunks on my trailer extend about 10 inches beyond the hull and would interfere with the tabs. After researching a few options it seems the most common fix for this is simply to cut off the bunks so that they are flush with the hull. Unfortunately I live about 25 miles from the lake so getting the boat in the water and then having a place to work on the trailer presents a bit of a problem and it may be sometime before I have the ability to get this done.

At the very end of last year I bent my prop and while the bend is not too bad (less then an inch) I prefer not to run it until it is replaced to be on the safe side. My original thought was to try going from a 21 pitch to a 19 to get on plane a bit quicker as I have read many people making a similar switch with some level of success. After reading so many positive reviews I have made the determination that I will be buying Smart Tabs but it may be later this season before I can get them installed and I will need to get a new prop long before that time.

So my questions for those with tabs or anyone with advice….

Did the tabs sufficiently improve getting up on plain or did you also combine with a lower pitch prop?
Should I stick with a 21 for now and wait to see how the tabs help or grab a 19 and then have both?

Additionally as a side bar…. You can spend all day reading about the benefits of one stainless steel prop over another but if you are searching for an aluminum prop (which I am) there seems to be little to no info on one brand over another. Anyone have a preference of a particular aluminum prop over another or are they all about the same.

Thanks,
Robb
 
robbo8199 said:
The bunks on my trailer extend about 10 inches beyond the hull and would interfere with the tabs. After researching a few options it seems the most common fix for this is simply to cut off the bunks so that they are flush with the hull. Unfortunately I live about 25 miles from the lake so getting the boat in the water and then having a place to work on the trailer presents a bit of a problem and it may be sometime before I have the ability to get this done.

At the very end of last year I bent my prop and while the bend is not too bad (less then an inch) I prefer not to run it until it is replaced to be on the safe side.
Click to expand...


you do not have to put the boat in the water to cut-off the extra bunk length....if you have a 'sawzall' saw (reciprocating saw) or can borrow or rent one you could leave the boat on the trailer and simply cut the ends of the bunks down as needed...should take 10 mins at most......

it does not take much of a deformation of the prop to cause significant performance issues...part of your slow planing time may be caused by the bent prop if the slow planing speeds were happening after the prop was bent...weight distribution in the boat has a significant affect on planing time...this is true for practically all boats with planing hulls so don't be concerned if you have to ask someone to sit in the bow seats to help with planing, especially if the engine in your boat is the base model engine and you are at or near full capacity with people and gear and fuel....

can't help you with a specific recommendation on prop selection for your boat or the addition of tabs, but as a 'rule of thumb' you can shorten planing time with a less pitch prop, but you have to be carefull to not go too low in pitch as you could possibly over rev the engine at WOT and possibly cause damage....lots and lots of posts concerning prop selection and the pros and cons of different size/pitch props in the archives, but it sounds like you have already been doing some reading of the archived posts...

you may also consider installing a hydrofoil to the outdrive....smaller boats tend to benefit more from the hydrofils...i put one on my 215EC and it made a noticeable improvement in lowering planing time and stabilizing the boat from side-to-side while on plane...i installed a Stingray hydrofoil (no affiliation with the company)...the hydrofils are also reasonably low price....

good luck...

cliff
 
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Thanks for the ideas Cliff. My initial thought was to use the sawzall while the boat was on the trailer but my bunks are wood with an aluminum support under it. While I may still be able to do it with the boat on there, going through the aluminum scares me a bit more with the hull sitting so close :smt089.

The planing has been in issue long before the prop was bent. Once it was damaged I haven't really used it as I didn't want to do any further damage.

I had considered getting a stainless prop but we are frequently in shallow lakes and I'd much rather have a bent prop then something worse so I think I will stick to aluminum. I only have a 3.0L 135hp so I'm not sure how much benefit I would get out of a stainless prop anyway.
 
You won't see much gain, if any, going to an SS with your set-up. The engine isn't going to spin the prop fast enough (much heavier than aluminum) to get the benefits.

You prop sounds like it is an ideal candidate for reconditioning. Most places have a 1-week turnaround.

If you're mechanically inclined, it is very easy to jack the boat off the bunks. Since you only have to raise the stern, it's even easier. If you're up for that, I can list a few pointers.
 
When I had my 180 BR I had two props. A 21 for when I was alone and a 19 when I had a full load. The smart tabs will definately help but it might be worth your while to get another prop also. Aluminum props are all about the same just make sure you get a price with the hub included. A four blade aluminum will definately give a little more stern lift but you should drop another inch in pitch to 18 to compensate for the drag of the extra blade.
 
I had given some thought to jacking the boat off the bunks but was not sure how to best accomplish this. I'd love to get a few pointers on the best way to go about it. Seems that as long as you can protect the hull this should be reasonably easy to get done.

Thanks Dennis
 
I ran an 18" 4-blade on my 180. It was fabulous for skiing - just watch out for the over-revving as mentioned above. I think I maxed out around 33-ish MPH. Looking back, Smart Tabs would of been the better choice.
 
blaster,

The vast majority of the time I go out I have a full load. That’s why I had given some thought to getting a 19 as well and then always have the other as a spare. Did you have smart tabs on your 180 or just change the prop out? Were both props just the standard 3 blade or did you give a 4 blade a shot? On Mercury’s site they list the Blackmax 3 blade 21 or the Alpha 4 as an option for mine.
 
Thanks Dennis...I rarely get going that fast so over-revving would not normally be an issue, but I would rather just stick with the 21 and Smart tabs to avoid the possibility all together. I’m basically just looking to plane quicker and at a lower speed. All indications seem to be that tabs would be the best bang for the buck to get this accomplished.

If you wouldn’t mind hitting me with a few pointers on jacking the stern up that would be great.
 
Put two jack stands up under the "A" of the trailer - about 3' back from where the two main beams meet. Basically, you want to take the stress off your jack stand and give a more stable base.

Ideally, you'll be placing blocks (two at a time, and then rotate the next two 90*, etc, until you finish with one block) under each aft corner with a piece of 2x on the top to protect the hull. But, depending on your bunk setup, you may be fine just blocking under the aft keel (about 2' in from the stern) if the boat will stay in good contact with the bunks - since they will stabilize it. The single block (on top) should be perpendicular to the row beneath it and parallel to the chine, but move it as far towards the center of the blocks as possible.

If you're going to end up with your hands between the bunks and boat, definitely go with the blocks under each corner. You'll likely use at least 5 blocks per corner. Maybe 7, depending on height.

To jack the boat, you can jack it up (again using wood - with which the graining should be placed perpendicular to the keel) right under the keel.

Be sure to do all of this on solid ground - or use a minimum of a 2' square of 3/4" ply on gravel or firm grass/dirt.

If you have access to something (overhead) that is strong enough to take the load, you could also lift the boat using the stern eyes and then place the blocking.

TAKE YOUR TIME and think things through BEFORE you do it. Then, STOP, and think again. Overall it's not hard - just have to be safe. I removed my first boat (completely from a trailer - pulled the trailer out from underneath) when I was 14. My dad came home and asked me "Why?". I said "Because I was curious". He shrugged his shoulders, walked away and said "Just be sure it gets back on".
 
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I didn't have smart tabs on the 180. I use the platform a lot and didn't want to have extra stuff to stub my toes on. When I was heavy I ran a 19 3 blade aluminum. When I was light I ran a 3 blade Laser 2 21" stainless I had left over from my previous boat. It was the fastest and maxed out at 44MPH at 4750 rpm's. The stock prop was a 21 aluminum which topped out 2 MPH slower and 50 RPM's higher. I never ran a 4 blade on that boat but I have a poweretech ele4 17 pitch 4 blade which runs perfectly on my 205 sport. It tops out at 4800 rpms and 48 MPH on my GPS. Its a noticable difference in hole shot and midrange over the 19 Vengeance.
robbo8199 said:
blaster,

The vast majority of the time I go out I have a full load. That’s why I had given some thought to getting a 19 as well and then always have the other as a spare. Did you have smart tabs on your 180 or just change the prop out? Were both props just the standard 3 blade or did you give a 4 blade a shot? On Mercury’s site they list the Blackmax 3 blade 21 or the Alpha 4 as an option for mine.
Click to expand...
 
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I've been meaning to get a thanks out to the folks at CSR that gave me some advice last fall on prop reconditioning. I'd have to dig for the thread. But, I got a recommendation for www.propmd.com . Compared to the local price for reconditioning, they were a great deal, turned my prop around in 8 days. It came home looking like new.

I had to get a new hub kit in the process, and when the new one arrived, the parts fit, but looked different. The drive sleeve went from brass to stainless and has a new general design. When I called Prop MD to verify they sent the right part, I got an answering service that said they are closed Thursday and Friday. An hour or so later, Ben, from the family that owns the business, called me and answered my questions. It doesn't get much better than that.

They also offer reconditioned props at what appear to be very good prices, what I want is out of stock. But I'm going to pursue getting a spare along with a hub kit to have handy.
 
blaster said:
I have a poweretech ele4 17 pitch 4 blade which runs perfectly on my 205 sport. It tops out at 4800 rpms and 48 MPH on my GPS. Its a noticable difference in hole shot and midrange over the 19 Vengeance.
Click to expand...

Blaster - how did you go about picking this, and can I just take that as a recommendation for my boat? I'd like to have a back-up handy, and trying something different seems like a logical way to use the money.
 
The smart tabs is definately the way to go. I had a 215EC that struggled to plane with any more than 2 people aboard. I put smart tabs on and that boat jumped up on plane with as many as 6. When I was selling her, the new buyer could not believe how quickly she jumped up. Easy install and a great company to deal with.
 
I've never tested a 205 with the 5.0 carb but I would imagine you would get a similar result. The folks an powertech are very friendly and offer expert advice. I tried 7 different props on my 205 when I got it. The 4 blade was the best for deep water slalom starts and speed control. The 19 Vengeance is the best all around prop and its a little faster. With full gas and 2 people I can still hit the rev limiter when I trim it out wide open. That leaves a little powerband unused but not enough to move up in pitch. When I ran the 21 Vengeance it was really fast. Time to plane was acceptable with 3 or fewer people and it planed off like my old 180 with the 3.0L. On GPS the fastest two way run across Belmont bay was 54 MPH which is impressive for a 21 foot boat with a v6. At that speed it rode way high out of the water and would get a little squishy in the rear end since the chines were almost clear of the water. I settled for the 19 stock Vengeance because it will still go 50 MPH with four people and their stuff. It planes pretty quick and will plane off with a max load.
Dave 205 said:
Blaster - how did you go about picking this, and can I just take that as a recommendation for my boat? I'd like to have a back-up handy, and trying something different seems like a logical way to use the money.
Click to expand...
 
blaster said:
I've never tested a 205 with the 5.0 carb but I would imagine you would get a similar result. The folks an powertech are very friendly and offer expert advice.
Click to expand...

http://www.ptprop.com/images/stories/docs/eclass.pdf

Thanks - I did check out their website, and it seems that they make props specific to the V-6. I'll have to try calling their customer service for assistance. I can't see anything that lists a V-8.
 
Dave - check your gear ratio. If it's the same as Blaster's, you can use the same exact prop. In his signature, he lists his as 1.62. You have the same HP as him. V6 or V8 doesn't really matter for what you're talking about.
 
Dennis - thanks. You confirmed with a little science what I had been thinking. There is a prop matrix on the Sea Ray website that lists an aluminum prop as standard for mine, and it was either optioned with, or the PO changed out to a 3 blade SS 14 X 19, probably Quicksilver - which seemed to make sense from the matrix. There is a barcode sticker still on my outdrive that states I have the 1.62 ratio.
 
My two cents......I have a 2001 bowrider 18 foot with the 135 hp 4 cyl and boat at higher altidudes from 6500 to 4,000 ft. I like the Mercury Black Max aluminum three blade prop for all around performance vs cost. They are easy to find and work well. I do not like the re-conditioning process due to past negative experiences. For what you do I would recomment the 19 Pitch. I recently purchased a Black Max 17" pitch by 15" diameter brand new with hub Kit on E-bay for a little over $100. I ran it two weeks ago at 4200 ft. elevation and got 37 mph at at max rpm of 4850. This was with full fuel and just me and the gear on board. I also have a 19 pitch 3 bladed black max prop that gets me right at 40 mph with 4500 rpm at the same elevation. You have nothing to lose by trying the prop pitch change first without the tabs to see if that makes a sufficient enough difference without the tabs. With that said, I wouldn't mind some tabs specifically to provide more nose downforce for improved ride control not so much for the planing issue.

Regarding the bunk board lengths. If it were me, I would weigh the tong weight and as long as you have considerably over 15 percent of the total weight of boat and trailer on the tongue, I would consider moving the boat rearward on the bunk boards by adjusting the bow stop position on the trailer tongue. If you only need to go back a couple of inches and you have sufficient tongue weight after the move, this would eliminate you having to cut the bunk boards at all. Failing that, you could move the whole board forward and re-attach rather than cutting the board length.
 
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