New guy with a project

[Cubman]

My name is Andrew and I was told about this site by 50hptiller. I saw the youtube videos of the SRG and would like to pick your brains about setting up my boat.

The boat is a 1648 Lowe (riveted) with a modified vee front, flat bottom, and 20" transom. The motor is a 1992 3-cyl Johnson 60hp tiller. I use the boat for bowfishing, frogging, and duck hunting. Normal load is two guys, two batteries, and six gallons of gas (about 650 pounds).

I would like to learn everything there is to know about my motor. I am 20, and my last motor was a '78 25 horse Evinrude, so I don't know a whole lot about outboards. I turned the prop once and the flywheel went around 2 and 1/3 times.

I am in the middle of building floatation pods, which I know are going to hurt my top speed, but it will help me walk the boat up into little creeks to find frogs and hopefully keep any water from coming over the back of the boat.

I installed a tiny tach, but haven't been to the lake since I put it on. I would guess that right now I am in the low 30s speed wise, I hope I can get a little more out of it.

My plan now is to finish the pods, install a jackplate, and get the proper pitch aluminum prop. When I get up some money I would like to buy a stainless speed prop just for fun.

My question for now is, how much setback is necessary on a jackplate to maximize performance? The transom has been plated with 1/4" aluminum so I am not worried about the leverage.

http://i187.photobucket.com/albums/x183/Cubman1944/379102240389.jpg
http://i187.photobucket.com/albums/x183/Cubman1944/379102234757.jpg

[orangebeast]

I would suggest to cut the head and go to a single stage reed

[Cubman]

Thanks for the suggestion, orangebeast. I am just looking to get the motor setup on this boat right now. Cody suggested a mercury chopper prop, is there a 13 spline equivalent that I can run on this OMC? And if you have the motor jacked up on the jackplate, do you have to worry about water getting to the pickup?

Do you think my boat will handle 6" of setback with that heavy motor hanging off the back? Or should I go more or less?

Thanks

[orangebeast]

It should handle that much set back, i run a high jacker plate on most of my motors i think the set back on them a 5

[Cubman]

I took the boat out yesterday. Total weight was 1000 pounds. I was running 36mph at 5300rpm. That is with the cav. plate just a hair below the boat. I trimmed it up way higher than I should have and got 39mph before it started to porpoise bad. Do you think there is room for improvement with a jackplate and prop or is this about as good as its gonna get?

[clough]

I took the boat out yesterday. Total weight was 1000 pounds. I was running 36mph at 5300rpm. That is with the cav. plate just a hair below the boat. I trimmed it up way higher than I should have and got 39mph before it started to porpoise bad. Do you think there is room for improvement with a jackplate and prop or is this about as good as its gonna get?

if you really wanted to get into it guys on this site have there 3 banger white motors doin crazy speeds....one guy on here put a turbo on a 49ci(i believe) yours is a 56ci..these motors are raced here in canada aswell...i dont know what the setup for aluminum boats(jons) is but as far as a jackplate and prop would go there is some deffinate speed there..im not going to say any numbers because i just dont know(maybe someone can chime in) but if you decide to run a surface piercing setup(chopper or cleaver prop) you are going to need a jackplate for sure...trim helps but what you can start off by doing is getting yourself a prop jackplate and pluging the top 2 water inlets on your motor(im not sure about omc but merc has 5 inlets) jack it up and if you cannot get the performance you want because your restricted by the water inlets...you can go 2 ways a transom mounted water pickup..or a nose cone nose cones are basically a cone that goes at the front of the lower unit that is either welded on or epoxied on (most guys will tell you to weld it) and at the front of the bullet of the nosecone there will be water pickups for your motor so that you could run the propshaft even with the bottom of the boat if you wanted to...ron hill the site moderator sells nosecones and so does bobs machine shop also he might have the prop you need as for a jack you can make one or buy one there about 200$ for a base line one..you can get adjustable ones that adjust with a wrench or you can get hydraulic if you really wanted to..and transom water pickups are sold at bobsmachineshop..google it...as far as setback and prop choice (i believe) setback is for bow lift...chopper props are for bow lift..and cleaver props are for stern lift..any other questions PM me...ive learned lots from these guys and s&f im only 16 ;):eek:

[clough]

http://i187.photobucket.com/albums/x183/Cubman1944/379102234757.jpg

looking at it now i would only plug one hole the sst60's have 2 inlets and a nosecone on there LU also i dont know my sh!t about LU as far as gear ratios but i know on these motors there are 2 gearcases one they call a nitro case and has a 1:87 gear ratio(i believe) and theres the other kind which is very bulky...cant remember how to tell the difference maybe someone can chime in...

[clough]

this is a nosecone notice the waier inlets at a lower position?
http://i256.photobucket.com/albums/hh197/jake_c_77/nosecone2.jpg








this is a transom water pickup it will pickup the water at the transom and when installe you will drill onto the impeller housing(like the nosecone^) and have a brass fitting like on the top of the transom water pickup and have a hose running from the impeller housing to the top of the transom water pickup...

http://i256.photobucket.com/albums/hh197/jake_c_77/PICT0016202.jpg

[Detroit Whitey]

Frist you have a rev limter on the ing system that you can change with a older style pac.Then you have to look and see if there is a hole drilled in the sleeve just in front of the exhaust port on each cly if so just put it back together and run it like a huntin boat.If there is no hole then you can build it up there is all kinds of bolt on`s like bigger and better carbs differnt flywheels,gearcases the list goes on and on.If it was mine i would look down the keel and see if there is a hook in the bottom that will cause it to porpoise no matter what.If it looks straight a good prop is the best thing you could do like a viper or srx good luck its habit forming so once you start its like crack its tuff to stop!!!!!!!!!!!!!;)

[Cubman]

Thanks for the help everyone. My lower unit is 2.42:1. Definitely not the best starting point, but it is what I have to work with. I would like to mess around with surfacing props but I can't afford to run $400 props when I spend time in 2 foot of water. I may invest in a PowerTech semi-cleaver just for fishing.

I knocked a significant hook out of the bottom of the boat. Perfectly flat it porpoised bad, so I put a slight hook on the bottom of the outside ribs and that fixed it. The motor used to cavitate when I had it as high as it would go on the transom, now it runs great.

Detroit, do you recall at what rpm the rev limiter stops the motor?

I took the motor off and laid it on its side while I was working on the transom. I hung the motor back on and was running down the lake wide open when the motor slowed down without me moving the throttle. It was running 5300; now its hard pressed to break 5000, and it doesn't like to idle. Could some trash in the carb bowls have been knocked lose when I laid it over, and now one of the jets is plugged? Or is this a fuel pump issue?

Thanks

[Detroit Whitey]

i would do a psi test on it after the slow down.Are you mixing or using the vro? that motor is prone to scuffing pistons.As for the rev limit is 6200 and it wont shut you down but the over heat system will it called S.L.O.W speed limit overheat warning If you get your motor hot this will slow you down and try and save it`s self after it cools down it will reset and you are off and running again but if the heat sender is fried it will trip it in to slow.This is one of the other reason`s we use the older ing system no rev limit and no slow but you`ll cook it for sure if your not careful .i use the same motor to run swamps for duck hunting It has new reeds bigger carbs and i jetted&timed it also used the pancake flywheel and running a 17pitch viper from omc and it will turn 6000 if i need it to

[Cubman]

Thanks, Detroit. Pre-mixing. Can you please explain the psi test. I need to put my fuel pressure tester right after the fuel pump to see what it is doing?

What causes a scuffed piston, how can you recognize this issue, and how do you resolve it? I think I will leave the limiter alone; hopefully it will keep me from burning up my motor if something were to ever happen.

I am buying a new set of 70hp carburetors next weekend with new reed cages and intake. Can I just buy a new intake gasket and swap the whole setup over? What sytle reeds do you use?

What kind of boat are you running and what speeds are you getting out of it? Are you in Trenton Georgia?

[Detroit Whitey]

the scuffing can happen with heat or lack of fuel.The 56cu blocks in that time frame had cooling issues there is actually a service bulletin on that.If you are running the vro pump still i would be careful the fuel isnt what it used to be and the diaphram is attacked and this will cause the lack of fuel you can use a standard pump they are more reliable.I should have side compression test all three should be with in 10lbs of each other if one is low pull the head off and check for damage or gasket failure.I run a 3cly on my race rig and used one up untill april on my 20 lund tyee and the set up would run around 35mph i have since switched up to a 115di tiller it makes a better set up.