2017 glastron gt185 4.3 merc/alpha drive 1.62 14.5 19 prop - porpoise

[H20Rat]

The transom plug, should be Out, anytime the boat is on it's wagon, Period,....

And is actually a law in many areas! Mine is installed right before backing down, and removed as soon as I'm clear of the ramp when loading.

To the OP, interesting to hear what the dealer has to say. Do you happen to have any side profile pics of the boat on the trailer with the drive all the way down?

 

[baconfudge]

QBhoy: i did the same with the noise trimming down, the boat is pretty quiet and it's easier to hear the pitch change when it's all the way down. Since i was "troubleshooting" if thats what you'd call it by trying different way to launch the boat onto plane i was using the gauge allot to just mark how much i was trimming up for each test, my basic test was full down trim/ full throttle, then full trim, 75% thottle, trim up 5%, full and 75%, tried slamming full throttle, tried kinda baby it up to full, etc etc, i put the boat on plane 40x at least from idle speed trying to find a way to keep it flat.

boat gets on plane really well imo, trim full down, i felt best quickly going to about 75% throttle (3000-3500 rpm) down and it comes right up on plane, just when the bow drops down it starts bucking up and down, wish i just had GF take some videos. i tried trim up after on plane but it just made bucking worse and i had to throttle back. tried trim up and adding thottle which made it scary bucking and throttled back. so in short i really didnt get to play w/ trim after on plane cause it was already bucking.

Bondo: if my ski locker is attached the bilge area and water is going to flow back and forth i have to plug it up or it will never stay clean. i dont leave the plug out of the little cooler deal under the seat. i'll watch if waves come in boat somehow and it gets water in there that i need to unplug the locker to let it drain out into bilge area.

transom plug i think im going to be on team always out until putting boat in water, i read these "forgot my plug" stories and my dads even forgot his before and he jumped in lake to put it in but i think i can remember it, no reason to be trailoring water around or trapping it in there in the driveway right.

 

[baconfudge]

pic fully down in driveway, reminds me, after parked it's best to store down or up? water came out of it when i lowered it in driveway. do you guys just lower to drain then raise it again or leave it down and raise before travel?

 

[JASinIL2006]

Good practice to keep the plug out always, except when on the water. If you're worried you'll forget, get a plug like the one below and hang it on your boat keys when it's not in use.

 

[baconfudge]

so boat is still at dealership, haven't heard anything from them but I'm pretty sure they aren't going to find a hull issue or trim issue w/ the sterndrive, it's 30 day warranty from them so better to have it in there and the problem documented than be outside the 30 day warranty.

that said i had email back/forth with nautica rep verifyied placement and pn; ordered the self adjusting trim tabs. I don't see any downside to them besides $$ and having to put holes for mounting.

talked to glastron tech about issue, his first question was if the hull was damaged, i told him i didn't see anything but it was back at dealership for inspection. I asked if he had heard of waterlogging and he said it was impossible for glastron to have waterlogged foam so, sure i guess. we then talked about the porpoising, he said he doesn't like to add anything to boats (trim tabs/hydrofoil) which again, sure glastron.

we then talked about the prop, 14.5x19p 3 blade and he said that would be more of the issue and it's not the prop that came factory on the boat (21p). we talked about 3 vs 4 blade and he said he did have some customers that saw better results from 4 blade props and magically he also had a part number right there for the prop. i thanked him and that was end of call.

seems him knowing the pn so quick points to a solution and also w/ boat being stern heavy a 4 blade should lift it better.

issue is..the pn which i didnt search until after the call.. a $700 merc rev4 ss prop. I mean, i like throwing money away as much as the next guy but $700 eh. I've also read/heard one comparison between alum/ss that alum prop will break but ss the prop won't so the sterndrive could, id rather break props than drives.

so researching forums on props i totally understand the wot and checking rpm then adjust pitch but obviously from post i cant get near wot w/ the porpoise so I'm going to start with one prop and test from there.

my choice right now is the turning point hustler 4 in 19p. i figure is 21p is factory, add a blade drop 2" in pitch. the turning point seems to have some people hate them and some guys love them. I think the 2 cupped blades and 2 stern lifting blades would help as well even w/ the trim tabs.

so question: being rev4 is dealer suggestion, is there a better 4 blade alum prop than turning point that would more closely mimmic the rev4? no rev4 available in aluminum. with the 2+2 blade design of TP prop I'd say that doens't mimmic the rev4 so maybe staying as close to rev4 design would be better than going with the TP?

 

[Scott06]

I have a rev 4 on my current boat very much like it because it has serious bite at full trim out not only do I get nice hole shot but also best top speed and stern lift with this prop. I bought mine used off eBay.

i cut my teeth with props on my old boat had really good luck with Michigan vortex 4 blade aluminum . These run even pitch so if you are replacing a 19” get a 18” 4 blade vortex etc. Nice hole shot great low speed planning and stern lift.

No personal experience with TP but would recommend the much vortex highly as a great value . My advice learn a little with aluminum props that are $150 or so then know what you need if u want to step up to stainless.

 

[Cortes100]

Hah, I've fooled around with props and know they can make you go crazy. There are so many variations between brands, it's tough to compare just by the pitch. Blade design, cupping, etc. all play a part. So far, best prop, I've been using Mercrusier and running a Spitfire 4 blade 21P aluminum.
Just for kicks, the other day I tried a BlackMax 3 blade 21P. Same brand, same pitch,

With these 2 props, the 4 blade Spitfire out performed in every aspect, pulled harder, smoother operation. Very noticeable difference.
The 4 blade pulls real hard on the bottom end, and on plane within a few seconds.
On Takeoff, the Blackmax raises the bow way more, The 4 blade keeps the front end down.
Cruising at 25-30ish mph doing sharp turns. Blackmax cavitated on occasion, but have never had that happen with the Spitfire.
With the 4 blade, can stay on plane at a lower speed. 2600rpm.
Top speed was not noticeable difference.
NO change on WOT rpm's.

And for the $$ I think the Spitfire was around $200. You can save $50 and buy the Quicksliver Nemesis. Same prop but does not come with hub assembly. Use hub from your Merc prop.

 

[baconfudge]

so got the boat back from dealership, nothing wrong w/ haul or sterndrive.

i had emailed with Nautica about the trim tabs, sent some pics and ordered the SX9510-60 as they instructed.

Decided to go with the Turning Point Hustler 4.

went out early today w/ Dad and tried it all out.

1. porpoise is gone, video below.
2. gets on plane quick, 2-3s and gets on plane at about 18mph/2800ish rpms.
3. turning is different/better. before it would dip the inside down abit, now it's pretty flat when turning, turns sharp, very responsive.
4. top speed wot/4400 rpm range hit 43 on phone speedometer. 1/2 tank gas, 600lb of men. (2)
5. idle steering is improved allot, barely strays now.

all in all pretty good results i think compared to slammer jammer teeth rattling porpoise to really flat..almost to flat.

so i have the trim tabs in hole 3, as i was getting 3800+ rpm i was trying to trim motor up to get the bow up and it really wouldnt rise much, i kinda feel like the trim tabs are creating to much down trim and it's fighting the motor up trim, going to try in hole 2 and see if i can get up on plane a little better tomorrow and i think that will increase the top speed a bit but all in all between the new 4 blade prop and trim tabs this boat is 1000% better driving.

maybe go 21p next prop also to try, get some more speed.








https://www.youtube.com/watch?v=vgcNMu6XSO0&feature=youtu.be

 

[Rick Stephens]

You are at the very bottom of the RPM range 4400 with the prop you are using. You will lug the motor badly and damage it if you go higher pitch.

 

[baconfudge]

so 17? i thought more pitch = more top speed

 

[Rick Stephens]

If you add pitch, the prop goes further through the water in one revolution. It also takes more torque. When the highest RPM you can get is 4400, and you should be aiming for 4800, then adding more pitch will make that condition worse. Like riding a 21 speed mountain bike with only the highest gear. Only time the bike is ridable is if you had a very steep downhill. At no time does your boat get to go downhill except in river rapids.

If you drop to a 17 inch it will speed the engine up to it optimum operating RPMs, right up near the top. It will get out of the hole much quicker and up to speed faster. It may not have as much top speed, or it may be higher. You can play around with a prop slip calculator to get an idea of what happens when you change pitch on props.

https://www.mercuryracing.com/prop-slip-calculator/

 

[baconfudge]

thanks for the tool, i think you are saying it backwards? im not sure about the slip field but if i want the boat to go faster (top) at 4400rpm then I'd need a 21p, calc shows it add 5mph; am i missing something? pic below.

that said i dont really need the top speed and i dont really want to run out and buy another prop; but i dont want to be stressing the motor running the incorrect prop either.

i don't think i got all the boat had today at higher rpm's because the trim tabs are on setting #3, as i trimmed up the motor i felt like the bow should be a little higher at top speeds to reduce the haul drag, no clue if tabs were pushed all the way up or not from water pressure but triming up should raise the bow and boat up on plane more than i felt it did, I'm going out tomorrow w/ gf so i set the tabs to #2, (less tabby) and we'll see if i can get better planing at high rpm and that hopefully translates into more speed and maybe more rpm then at wot. my wot was right at 4400 rpm. so less tab trim + motor up trim = better planing = more fun is my thought.

also considering i have alum prop and at high rpm they somehow are less effective because less sturdy than steel prop? is that still a thing w/ 2020 alum props or that like a 90s stereotype? if so maybe this TP prop is what you say? flemsey at high rpm.

 

[Bondo]

i think you are saying it backwards? im not sure about the slip field but if i want the boat to go faster (top) at 4400rpm then I'd need a 21p

Nope,..... Rick is right, 'n yer not,.....

Yer motor ran outa horsepower at 4400 rpms, droppin' pitch will allow it to build more power, up to 4800 rpms,....

 

[baconfudge]

why does the calc show it the other way? because I don't have right data obviously.

Im obviously new to owning a boat, trying to wrap my head around the way it all works together. i keep reading less pitch is better hole shot but higher pitch is better top speed. but that really should have an * that higher pitch is better top speed if you haven't maxed out the rpm.

so in theory my motor can go to the rev limit (4950?) something like that but don't do that; id want it to be at 4800 for wot testing; but between prop type, boat weight, and i guess haul resistance my setup has maxed out my motor at 4400 rpm so if I were to have lower pitch prop that creates more rpm, less weight or better planing (resistance) my wot rpm would be higher.

so in reality with this wot testing speed is an outcome but what I'm really looking for is the max rpm at wot? and since im 4400 rpm my motor is working to hard and i can reduce the burden on it by lowering prop pitch. correct? and with the speed it is what it is at 4800 rpm after I'd get 17p and that shouldn't be my focus, my focus should be the boat being setup to run its best which is really being able to get up to 4800 rpm at wot.

if that's correct and im just boating normal 3000-3500 rpm how bad is this prop/setup for the motor? on scale of 1 (dont worry) to 10 your motor is going to be trash soon.

 

[Bondo]

so in reality with this wot testing speed is an outcome but what I'm really looking for is the max rpm at wot? and since im 4400 rpm my motor is working to hard and i can reduce the burden on it by lowering prop pitch. correct? and with the speed it is what it is at 4800 rpm after I'd get 17p and that shouldn't be my focus, my focus should be the boat being setup to run its best which is really being able to get up to 4800 rpm at wot.

Ayuh,..... This is correct, ^^^,...... You want to motor to build horsepower up to 4800 rpms, it's peak,......

It'll turn whatever pitched prop at that rpm, 'n be goin' whatever mph,.....

if that's correct and im just boating normal 3000-3500 rpm how bad is this prop/setup for the motor? on scale of 1 (dont worry) to 10 your motor is going to be trash soon.

Yer runnin' at the very bottom of acceptable rpms, the end probably won't come tomorrow for yer motor,....... But,......

Luggin' the motor at Wot, is luggin' the motor from idle on up in rpms,.....
It makes detonation easier to set up, 'n detonation can kill yer motor in minutes,....
Advanced timin' don't happen very often, but a lean condition sure can, 'n that causes detonation easily,....

 

[baconfudge]

thanks for responses.

not exactly sure what detonation is, seems pretty much as bad as it sounds from quick forum search. anything w/ pistons and heads is way out of my wheelhouse to repair.

i really see the need to be able to test props w/out buying them, i asked dealer and he said they didnt do loaner props, with pitch, rake, diameter, cupping, alum vs ss, and probably 10 other things i dont even know about it would nice to just try them but guess if you dont experiment and try diff props how would you ever end up with a shed full of old props right?

 

[Rick Stephens]

thanks for responses.

not exactly sure what detonation is, seems pretty much as bad as it sounds from quick forum search. anything w/ pistons and heads is way out of my wheelhouse to repair.

i really see the need to be able to test props w/out buying them, i asked dealer and he said they didnt do loaner props, with pitch, rake, diameter, cupping, alum vs ss, and probably 10 other things i dont even know about it would nice to just try them but guess if you dont experiment and try diff props how would you ever end up with a shed full of old props right?

You nailed it. We all read up like crazy, talk to other users on the forum, and pick something. Then, if by some small chance it really works, we talk like it is the second coming and everyone gotta have one or they are mudsuckers. Most of us find something acceptable pretty quick. Or we hit the RPM at WOT spot and are satisfied easily with everything else. There are some really good advisers in the Prop Forum, but they are flying by seat of pants too, on YOUR boat, since every boat is unique.

Of note, I never found any difference in top end performance with my tabs at top or bottom setting. I leave the driver side at highest setting since I weigh twice as much as my wife and I set her side a hole or two less. That way she's not mad at me for running a crooked boat.

 

[baconfudge]

moving trim tabs from hole 3 to hole 2 didn't help w/ motor trim up planing, only did wot once and it was still 4400 rpm max. i did have cooler and more gas in boat but went ahead and ordered the TP 14x17p prop. hopefully get back out next weekend to test that prop out.

also i noticed when i did trim up i could get the boat to porpoise abit and then i trim down a bump and it would go away so going back to hole 3.

 

[Rick Stephens]

moving trim tabs from hole 3 to hole 2 didn't help w/ motor trim up planing, only did wot once and it was still 4400 rpm max. i did have cooler and more gas in boat but went ahead and ordered the TP 14x17p prop. hopefully get back out next weekend to test that prop out.

also i noticed when i did trim up i could get the boat to porpoise abit and then i trim down a bump and it would go away so going back to hole 3.

You got it. I never really stopped playing with the Smart Tab adjustments. Like you trying to find the perfect combo. It is great having them though. I already wore one out. You want to see a wife with that evil eye, when one gas shock lost pressure a year or two ago, the boat leaned way over at anything over a walking speed. I had to back into a ramp and go wading to disconnect the other one fast. Made to walk my own plank :^)

 

[baconfudge]

well i could go 4900 rpm w/ the TP hustler4 17p, i think it might have had a bit more cause i wasn't WOT but very close, i didnt want to hit the rev limit so i just kept nudging it. top speed 38 w/ 3 of us, cooler, full tank, some waves from windy day. i think im going to call that good, the boat seemed to run better with the 17p. motor felt less stressed, with tp 4 blade and trim tabs im up on plane pretty much in 2-3 seconds at maybe 15 mph. tubing was easy today and my daughter actually said dont take off so fast

im really happy w/ the trim tabs, it was choppy today and i could run about 3200 rpm w/out much bouncing, lil faster and it would start jumping wakes eventually, i could see today how it would be nice to be able to adjust the tabs though but the cost of driver changable trim tabs just seems excessive for the boat and what im doing when these work pretty good.

i only used the 3 blade prop twice but i can really feel the difference w/ 4 blade, especially in turns, if i trim down as i turn i can can crank into a turn pretty hard and push the throttle, good power, no skip/sliding, stays flat where first couple times out the boat really banked into the turn, part of that is probably the 4 blade and part the trim tabs but boats enjoyable and drives well now.

thanks for everyone's input.