120 hp tach/placement/performance questions

[jake3020]

Guys, i have read so much information on this site and alot of it on Tachs. I went through the entire wiring harness Looking and tracing the "purple" wires. trying to figure out why the tach wouldn't work at all. I finally found that at the motor, there was two yellow wires that run into the voltage regulator had arc'd together. I cut the connections and reconnected.

Now the Tach works, but is reading way too high. it shows idle at 3,000 rpm (book sais it should be 700-800), and WOT is pegged off the gauge (should be between 4500-5250). I started down this path because I am very disappointed in the performance of this motor on a tracker PD21 deck boat I bought and through all the research that i have done on this site an others, i understand that until i have accurate tach readings i cannot get worthwhile recommendations. does the information on the tach above lead you to believe that i should just switch out the tach? or is there something else going on with the wiring? see attached pics labeled "tach 1" and "Tach2"

So i will also list my other issues here in the hopes that others will chime in and offer their thoughts as i work closer to getting this set up to perform to it's best abilities ( even if that is below my expectations).

1) when you are at WOT, with the motor trimmed for max performance, water comes pouring over the transom as if it is catching the front of the lower unit and funneling it up...I?m talking a major amount of water here!!! i think that the motor is sitting two low in the water and am questioning the need for a jack plate... I could only gain 3" by moving it in the factory provided holes ( it is currently set as low as possible).. What do you guys think? see attached pics for reference "motor mount 1" and "motor mount 2". there is no way that this water coming in like this can be normal. Through all the research I?ve done, I?m thinking that the anti- ventilation plate can be as high as 1? above the bottom of the hull ( that is about 5? higher than currently mounted). The current mounting holes will only allow the motor to be raised 3?.

2) My prop is a Stiletto M1323 ( doesn?t this mean that I have a 13inch- 23 pitch prop?...What does this mean to me with my set up?

3) When i am running at WOT, 26mph, I?m getting alot of spray from the front of the boat. it makes me think that if i was going a bit faster, and the boat was running higher in the water, then i would be above all of that.....The hole shot is OK, if you get on the trim immediately. This spray is very, very bad...All of my testing has been done with my wife and two small children. This will be the usual load. i also attached an overall pic of the boat so that way you can get a feel for what it's all pushing. I wish i could tell you what the weight was, but i cannot find that info.

4) so my gut is telling me ( yes?being the newbie that I am ) that I should raise the motor 4-5?, go with a higher speed prop..say 25 or 26 pitch?and maybe add a hydrofoil to help with the hole shot (because of the higher pitch)?..I make all that assumptions on not really knowing anything about this?..thus the questions I?m asking.

I know that it will be hard to assert a major breakthroughs with the proper tach information, but maybe your advice will bring me closer. Thanks so much in advance for any information. Sites like these are amazing and it seems that no matter what I?m ?into? at the moment, these types of forums always help me do it better.

if the pics are too small to see accuratly then I would be more than happy to email out.

also if you think that some of these questions would be better answered on another forum catagory than let me have it...

 

[jake3020]

Re: 120 hp tach/placement/performance questions

more pics

 

[jake3020]

Re: 120 hp tach/placement/performance questions

Guys, I went ahead and raised the motor today. That out the anti-cavitation plate at 1" above the bottom of the hull. So we decided to take it back out on the water and check performance...... And there was absolutely no change in performance at all ( except i don't have to move the tilt up very far and the rop starts cavitating). Does anybody have any suggestions? This is very disSapointing to me....



I will note that water no longer comes rushing over the transom now that the motor was raised!! So that problem was fixed, but now stearing is harder than ever.
My father in law watching the boat on the dock thinks that there is not enogh motor there to get the boat up on plane thus all the water splash from the front and low speed. Personally I could care less about speed, I just want it to ride "above" the water insted of trying to push it lime a bulldozer!!! This is a deep v design.

 

[hwsiii]

Re: 120 hp tach/placement/performance questions

Jake, I have already left a form for you to fill out, I must have lost my connection when I submitted the form.
I have no idea what boat you have, but from the picture it looks like a deck boat of some kind. The water was coming over the transom because the motor was mounted too low on the transom. What is the tach switch set to on the back of the unit. The arc could have shorted the tachometer out and that is why it is reading wrong. I show a Stiletto 31323 to be a 13 1/4 x 23 Advantage II prop, and I don't know your gear ratio, but I would say off hand that is too much pitch.
Please fill this form out and I will help you as much as I can.

Iboats Boat and Motor Info

1. Year, make and model of boat
2. Length, width and base weight of boat, look for boat decal on back of boat
2a.What is the maximum recommended HP for your boat
3. Number of people and gallons of gas normally on boat
4. What do you use the boat for
5. Is it a Deep Vee and if so how many degrees of deadrise
6. Year, make. manufacturer and model of motor
7. HP and gear ratio of motor IMPORTANT
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene
10. Is it a bass boat or does it have a pad bottom
11. Does it have a hydrafoil, dolefin or trim tabs
12. Make, model, diameter, pitch, number of blades and whether SS or aluminum prop
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a digital tachometer and hour meter here: http://cgi.ebay.com/ebaymotors/Tacho...Q5fAccessories $ 35
RPM _________ Speed ______ GPS ______ No. of people ______ Gal. Gas ________
14. Are you at sea level or a higher elevation, give us the elevation in feet
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way by just pushing the throttle at the helm and not at the carburetor, checked compression, and looked at the plugs and checked spark as well as timing and advance, all of the foregoing could be the reason your prop is not attaining full RPM
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations
19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.

REMEMBER, The numbers I give you will be NO better than the information you give me

The only thing I ask of you is to come back and give me a report of WOT RPM and speed for my database.



H

 

[Frank Acampora]

Re: 120 hp tach/placement/performance questions

jake: You did not say the year, but you have a Mercury built Force with a Mercury lower unit and most likely Mercury ignition. The alternator is most likely a 20 pole alternator and the 0-8000 rpm Tach is probably the correct one. HOWEVER: If your tach is one of the ones with an adjustment switch in the back--I can not see in the photo-- The switch must be set to position #4 for 20 pole. Position #3 is 12 pole and will read way too high. HOWEVER: Double check to see that the tach is a 20 pole tach. These are used (to the best of my knowledge) only with Force and Mercury engines. Most manufacturers do not make this tach. Teleflex sportsman red 0-8000 is one of the very few I have seen.

Also, Merc used different wire colors and the purple wire may not be the correct tach wire. The correct signal wire will be one attached to one AC terminal on the rectifier or regulator.

Now: do you see the wide plate just above the anti-ventilation/cavitation plate? (splash plate) When water impacts the lower unit while running it tends to run up the engine leg and pour into the splashwell. That plate stops this and directs the water outward, away from the engine. IF the engine is sitting too low, as it is in the photos, with the splash plate even with the bottom, that plate can not perform its function. So you MUST raise the engine until it does stop water intrusion into the splashwell. Raising the engine will, however, reduce the amount of trim you can use before the prop ventilates. Cupping the prop will reduce this a bit and allow a bit more trim.

Heavy steering is a function of the engine being trimmed in too far. SO: you are caught in a catch 22 situation--damned if you do and damned if you dont.

FIRST get the tach working properly, THEN raise the engine to the point where you stop water intrusion, THEN play with props to try and gain correct performance.

With the problems you have, it may take a bit of time and some patience.

One inch above the vee may be too much. It is not a hard and fast rule and varies with hull design. On my 21 foot cuddy one inch above the bottom is too high. So, anti-vent plate even with the veee or slightly above may be enough to stop water problems.

I would also try re-drilling some mounting holes because a difference of only 1/4 inch can make a drastic change in performance. Currently you only have the option of 1 inch changes. You may find that, for example, only 1/2 inch above the bottom will stop the water problems and ventilation will not be so drastic. Perhaps if money is not a major consideration, a jackplate would be a reasonable investment. Remember that with a jackplate setting the engine back 5 or so inches, the water will be further away from the transom and intrusion will be less. Also, since water tends to rise off the bottom of the transom as the boat is travelling, the engine can be run higher without ventilating.

 

[jake3020]

Re: 120 hp tach/placement/performance questions

ok, i still have to get the tach working, but this is what i have so far.

answer
1. 1997 suntracker PD21 deckboat
2. 20'-10" longe, 92" wide at widest point at hull/transom. Not sure what base weight is but all I can find is where it reads " 10 persons 1,400lbs" and below that "1,975lbs persons, motor"
2a. 150 HP
3. 2 adults, 2 children (or about 400 lbs), gas is about 20gal
4. currently just messing around, these problems are making me question what can I use it for??
5. Deep Vee?.i'm not sure how to do this, but I used a 2' edge and measured at the end of it (leveled edge) and measured 9"?so that is 9/24 or 4.5/12..is this enough to get close to the degrees? I'm sure you know around about what it should be or hopefully this is close enough for your calcs
6. 1997, force by mercury. 120 HP
7. 120HP. 2.07:1 gear ratio( per the motor manual..i assume you are talking about the lower unit here??)

8. max rpm per book, 4750-5250?.idle rpm 700-800
9. 1" exactly ( now that I moved it up)
10. not sure what you are asking for here?
11. no
12. stelletto M1323 is all I have to go off of.
13. my tack might be working?see below post about the setting in the back?if this works then I will take it back out this weekend.

14. 192m (630ft)
15. no to all of this
16. just bought the boat. This was the prop on it/
17. no
18. as noted in post above
19. just want it to plane out

 

[jake3020]

Re: 120 hp tach/placement/performance questions

frank, see below pic, this is what my tach looks like. it has these following settings.
2p, 4c
3p, 6c
4p, 8c
5p
6p
it is currently set at 2p, 4c (arrow is facing this set of numbers anyways)
so as you can see, i'm not sure which one of these is the #4 position as you noted...with one should it be set at? I do remember messing with this adjustment as i was looking for loose wires (before i found the short on the voltage regulator).

 

[jake3020]

Re: 120 hp tach/placement/performance questions

i was able to track the purple wire all the way back to the top cylinder in the engine...but this same wire runs to all the gauges on the dash...i quess this is normal...

 

[jake3020]

Re: 120 hp tach/placement/performance questions

forgot to attach pic of back of tach...sorry for all the multiple post.

 

[moparman]

Re: 120 hp tach/placement/performance questions

looking at the picture it says 4cycle on it ,or am I seeing things ????But[there's that word again] looking closer you can see the part that says p= pulse and c =cyl,so that would be 4 cyl,2 pulse [don't know if that's per rev or not]but it says 4cycle gas on it ,you can't really see all of it ,can you post a better pic?

 

[Frank Acampora]

Re: 120 hp tach/placement/performance questions

I left your tach answer over in the prop forum. I thought perhaps you would go there first because of your other problems.

 

[jake3020]

Re: 120 hp tach/placement/performance questions

HWSIII,

alright i've got the tach working. and today the sun was shining and made for a good day to get the boat back on the water and run these tac test.
see below for a complete run down of your questions.
after this test it is clear to see that my WOT is below the manufacturers specs.

answer
1. 1997 suntracker PD21 deckboat
2. 20'-10" longe, 92" wide at widest point at hull/transom. Not sure what base weight is but all I can find is where it reads " 10 persons 1,400lbs" and below that "1,975lbs persons, motor"
2a. 150 HP
3. 2 adults, 2 children (or about 400 lbs), gas is about 20gal
4. currently just messing around, these problems are making me question what can I use it for??
5. Deep Vee?.i'm not sure how to do this, but I used a 2' edge and measured at the end of it (leveled edge) and measured 9"?so that is 9/24 or 4.5/12..is this enough to get close to the degrees? I'm sure you know around about what it should be or hopefully this is close enough for your calcs
6. 1997, force by mercury. 120 HP
7. 120HP. 2.07:1 gear ratio( per the motor manual..i assume you are talking about the lower unit here??)

8. max rpm per book, 4750-5250?.idle rpm 700-800
my current idle is at 1000 rpm
9. 1" exactly ( now that I moved it up)
10. not sure what you are asking for here?
11. no
12. stelletto M1323 is all I have to go off of.
13. WOT is 4,300 rpm....gps speed is 27.1mph

14. 192m (630ft)
15. no to all of this
16. just bought the boat. This was the prop on it/
17. no
18. as noted in post above
19. just want it to plane out. I went ahead and did the test here as you mentioned while i was testing it out. these are the results.
1500rpm-7.0mph
3,000rpm-20.8 mph
3,500rpm-23.6 mph
4,000 rpm-26.3 mph
4,300 rpm-27.1 mph WOT.

Hopefully this will give you enough information to help me out.
it is kinda sad to have this boat and not enjoy it. I took my son out with me tonight and he had to sit at my feet to keep from getting wet ( and i got soaked) becuase all i am doing is pushing the water instead of getting up ontop of it!!!

 

[jake3020]

Re: 120 hp tach/placement/performance questions

also on another note. I'm thinking that maybe i need to change my steering cables. but before i do, i want to know if you think that the angle that the cables leave the splashwell to the motor is too much and maybe the problem? i don't want to spend the money on new cables only to find out that i have the same problem.
i went ahead today and removed the steering rod from the motor today to make sure that the stiffness is in the cables and not the pivot pin at the motor. you could move the motor with your pinky without the steering cables attached, so i know it is in the cables.
the steering is so stiff that my wife cannot turn it and i have to struggle. this is way to dangerous to keep like this and not very enjoyable to drive.

would you reccomend i go with another single cable system? or the double?
I know the best would be the hydrolic, but look what the cost!!
see pic

 

[jake3020]

Re: 120 hp tach/placement/performance questions

i forgot to tell you that for these test tonight. there was at least 25g of gas (just filled up before testing). Myself 200lbs and my son 45 lbs.

 

[huskerdaninva]

Re: 120 hp tach/placement/performance questions

"jake: You did not say the year, but you have a Mercury built Force with a Mercury lower unit and most likely Mercury ignition. The alternator is most likely a 20 pole alternator and the 0-8000 rpm Tach is probably the correct one. HOWEVER: If your tach is one of the ones with an adjustment switch in the back--I can not see in the photo-- The switch must be set to position #4 for 20 pole. Position #3 is 12 pole and will read way too high. HOWEVER: Double check to see that the tach is a 20 pole tach. These are used (to the best of my knowledge) only with Force and Mercury engines. Most manufacturers do not make this tach. Teleflex sportsman red 0-8000 is one of the very few I have seen."- Frank Acampora

Frank I am not trying to hijack this thread but you may have just answered a question for me. If my old US Marine/Faria tach has the settings on the back for 1,2,3,4 does that tell me that #4 setting is correct, and it is compatible as a 20 pole tach that my 1969 motor requires?
If I am posting in an inappropriate fashion feel free to remove/move this post. I don't want to break the board guidelines. Thanks guys!
Dan

 

[RRitt]

Re: 120 hp tach/placement/performance questions

Jake I don't know if this applies but I had a similar problem with my boat plowing the water. I had two engines, two batteries, and a 100 gallon tank all sitting within 12" of the transom. With a full tank it sat nowhere close to flat on the water. When I gave it gas it would dig in and plow before eventually getting up on plane. I moved both batteries forward to under the console. It took some HEAVY cable and some rigging to protect against bouncing and to not lose voltage across 20' of cable. But in the end it was worth it. All plowing issues went away, the boat sat level on anchor, and it got up on plane almost immediately. Most importantly, I never again had a dead battery or post corrosion. Both the on/off switch and the batteries themselves were in a watertight area isolated from any salt water or spray. For me, it was a win-win-win modification.

 

[Alaninga]

Re: 120 hp tach/placement/performance questions

Did this deck boat ever get a proper pitch prop?
I'm looking at a 21' Tracker Fun Deck for sale and need to know if this is a good boat or a quirky boat!
Thanks, it's an old post but I need to know all I can before buying a 'problem' boat!

 

[jerryjerry05]

Re: 120 hp tach/placement/performance questions

The poster never completed his post then so I doubt he's even looking at the forum now.
You need to post a new thread and ask there.

Include as much info as you can.

Elaborate on Quirky!!!!!
What you've heard etc.

 

[1580rick]

Re: 120 hp tach/placement/performance questions

Alaninga,
I have a 2002 PD 21. I haven't had it very long, but my family really enjoys the boat. Great for cruising the lake. Very smooth ride. I have a pylon on the back and it pulls a tuber ok. But the motor kicks up water and the prop leaves a rough wake. The skiers and kneeboarders have to ride outside the wake. I'm working on this problem, but it seems the back of the boat has a design flaw. Still working to try to overcome this problem.