1995 Johnson 130 Looper

[jwall116]

I am going to do RPM VS GPS speed tests tomorrow and will report my results. Full fuel and 2 people for the testing.

No way you are getting full syn for $20 a gallon, Syn blend is what I am running from wallyworld. $17.99/gallon.

What cruise RPM yields you 6-7 GPH? My rough guesses are somewhere like this: I made up this chart below using fuel data from other 2 strokes and averaging them out. The new ETEC engines have a very different burn than our engine when the power is reduced, so most of this is from a Merc Opti engine.
4000 - 6.5
4500 - 8.5
5000 - 10
5500 - 13.0
6000 14.0

 

[sutor623]

Yea sorry I meant pennzoil syn blend. That stuff works fine for me. But, you have to decarb more often. If you run the evinrude xd50 oil I believe it has a form of carbon guard in it. Twice the price, but possible worth the money............

My the cruise speed that I get 6-7MPG out of the boat with is 4200-4400rpms. I ran an above deck 6 gallon fuel tank filled to the brim 2 times while cruising at 4200rpms (23-25mph, depending on wind, trim, load, current etc.) and both times I ran the tank completely dry in about 55 minutes of running. I am very curious to hear about your results. I will be out on saturday and we can compare data. i will do some speed/gps comparisons also, full fuel and me and the admiral aboard!!

 

[sutor623]

So I am having a hard time seeing these rpm vs. prop slip numbers add up. They seem very incomparable when looking at our two setups.

FYI, I am using the mercury prop slip calculator. (Our gearcases have a 2.25:1 gear ratio) My prop is 17p http://www.mercuryracing.com/prop-slip-calculator/
For what its worth, I have only confidently recorded my WOT GPS speed vs. tach readings. (I have verified my tach is working properly with an add on electronic tiny tach.)

With VERY heavy load (full bait tank, batteries, fishing gear, three people on board), trim tabs deployed I am running 5450 rpms at 35MPH. This yields a 10% prop slip. Beautiful slip numbers.

With 400 lbs. less load (empty bait tank) and same load otherwise, I am running 5600 rpms at 36MPH. Again, 10% slip.

With just me on board and no bait tank I am running 5700 rpms at 36.7MPH, 10% slip

With just me, no bait tank, half tank of fuel, trim tabs disengaged entirely, I am running 5850rpms at 37.5MPH. (Porpoising like crazy!!) and again, 10% prop slip.

I am running an aluminum prop with very little cup. (14.8 x 17)



Now, lets take your prop slip numbers into consideration.

First of all, an SS prop that has been cupped should bite MUCH better than my aluminum prop, and your slip should be LESS than it would be with a cheapie aluminum prop. It should also lug the motor down more, not less. If I put your prop on my motor, it would take my rpms WAY down.

Lets look at your rpms in the 5500-6000 range.......

At 5500 rpms, 19p prop, 36 MPH, your slip number is 18.

At 6000 rpms, 19p prop, 41 MPH, your slip is 15.

These slip numbers are not unheard of, but why when you are running a lighter load and a nicer prop on the same rig, are your slip numbers 50-80% higher than mine are??? I just do not see how that motor can spin a 19p prop up that fast with a boat this heavy.

Lets assume that your 20 year old tach is acting a little wonky, and see what your RPM numbers would be at the same GPS speed, with a 10% slip:

19p, 36mph, 10% slip yields 5000rpms at 12% slip it reads 5200 rpms (as compared to your tach reading of 5500).

19p, 41mph, 10% slip yields 5700rpms at 12% slip it yields 5800 rpms (as compared to your tach reading of 6000).

I hope to get some feedback from others here, but I really believe that your tach is not reading properly. Something just isnt adding up here............

 

[sutor623]

Is there a chance you are running the smaller v4 gearcase on that motor? Do you have a pic of the lower unit?

 

[sutor623]

Hey man, just ran into this on CL, thought youd be interested in it. Our boats with a hard top Takes up a lot of room, and would keep me from getting under the bridges at the lake, but looks awesome!!

Also very interesting that Chris Craft bought the hull design from OMC. She claims the boat goes 50MPH, but I think she may be exaggerating a few MPH, especially with that hard top on there

http://richmond.craigslist.org/boa/5635227330.html

 

[sutor623]

Hey man, did you end up making any runs yet? I am going to make some speed vs. rpm runs this weekend..............

 

[sutor623]

Did some solid runs yesterday. Got my top speed back out of the boat. I actually had the 60lb actuators on my trim tabs, and stepped down to the 40lb ones and no porpoising, easy planing, and great top speed. SX told me to go with the 60lbs but that has proven to be overkill.

Anyways I ran the boat with just me and about 3/4 tank of gas and here was my three sets of findings:

WOT was turning 5800 rpms at 38MPH which yields 9% prop slip. Great number there!!

Favorite cruise 4200 rpms at 26MPH which yields 13% prop slip. Liveable number there, and good gas mileage.

Minimum planing 3600rpms at 18MPH which yields 30% prop slip. Terrible gas mileage there, but nice slow comfy ride for the lil ones when necessary.

All in all, the prop trim actuators have helped me to maintain top speed (from where it was without the tabs) plane out very easily, keep the bow lower for increased visibility, and eliminate porpoising when trimmed out to the max. Happy camper here!!! Let me know what you got on your last run.

 

[jwall116]

I did some playing around, and found your 4200 RPM cruise to not be too shabby. I found I can get 25 mph @ 4200 RPM with her trimmed up as high as I could without bobbing like crazy. Seems I was not trimming up high enough, previous i was using 1/3 trim up before it started to porpose, if i keep going up from there it will stop so I have been running at 1/2 trim up and my speed #'s have come up.

This gives me a prop slip # of 26. WHAT THE HECK??? I do agree that a 19 pitch prop should be putting more of a load on the motor than it does. My prop has been repaired in the past and I also had it repaired, so im guessing it has lost some diameter and maybe some pitch. I might be open to a cheap alum prop from ebay! lol

Anyways, the good news with this is..... I just purchased a Navman F210 fuel flow gauge. It may take me a week or two to get the item in the mail and then installed and test but we will have actual fuel burn #'s to go by. This is not found anywhere on the internet, no idea why but I will provide it from idle to 6000.

 

[jwall116]

Here is a video of the engine idling in the driveway.

https://www.youtube.com/watch?v=IFxPmgEp8N4

How can I verify the tach without spending a fortune. The needle is steady no matter the rpm but it is 21 years old.

Even though our prop pitch is different.. per whats stamped on my prop our speed and RPM #'s are the same. 5800 also gives me 38 MPH. WOT and 6000-6100 gives me 40. Getting 40 on this boat is hard to do, must be calm and trimmed up. I'm really voting towards my prop lost diameter in the repairs.

 

[sutor623]

Hey bud, thanks for getting back. Really cool and fun to do this sort of comparison. Hard enough to find someone with the same setup, nevermind interested in spending the time and energy to figure out the stats. Im looking forward to hearing how your fuel flow meter works out.

As for determining if your tach is efficient, I bought a $10 tach/hour meter from ebay. Wrap the wire around one of the plug wires, and run the wire up the shift linkage and stick the meter on the transom with double sided tape. Good to see hours run and rpm verification. I am idling at 800-850rpms in neutral and 600rpms while in gear. My tach on the boat seems accurate within 50 rpms or so.

Prop diameter is definitely another key factor here. But, I was doing some thinking. Your motor may also be set up higher than mine is. My motor is set at the second hole from the top, meaning I have two more bolt holes to move the engine up. I wonder if you are one bolt hole higher than me. This would expain the pitch change and need for cupping. Most people say that if you raise the engine, cupping of the prop is necessary. If I cupped my prop at the height my engine is at, I dont think Id be happy with the results..........

I am glad that you are happy with the 4200 cruise speed. It feels real nice on my rig. Boat will handle a hefty chop on a saturday at the lake, and keep us dry on our voyages.

I am nearly positive that my boat would handle moving the engine up at least one bolt hole. Reason that I say this is that I can trim the motor up to the max (just before tilt kicks in) and not blow out (except for around hard turns.) I almost always have a full bait tank on board this boat, and going out empty this past weekend I realized something. This boat comes out of the hole and handles beautifully if you keep it at a reasonable weight capacity. She drives good with that heavy bait tank back there, but boy is it fun riding solo or with one other person on board Be super nice to have a hydraulic jack plate on here!!!

I had a really nice 2003 150 Yamaha longshaft given to me a few months back. Man, I often wonder what that engine would have done back there. I bet it would have been fun!!! I didnt want to spend the $300 on Yamaha controls, have to swap engines, and buy another prop for the Yammie, or else I would have done the swap. Ended up selling the Yammie for $4250, so no complaints here. They sold a lot of these boats with the 150 on the back. My guess is that would have been a fun setup. I dont feel underpowered AT ALL with the 130 back there............ Thanks to that big 2.0L 4 cylinder block

 

[sutor623]

I did some playing around, and found your 4200 RPM cruise to not be too shabby. I found I can get 25 mph @ 4200 RPM with her trimmed up as high as I could without bobbing like crazy. Seems I was not trimming up high enough, previous i was using 1/3 trim up before it started to porpose, if i keep going up from there it will stop so I have been running at 1/2 trim up and my speed #'s have come up.

This gives me a prop slip # of 26. WHAT THE HECK??? I do agree that a 19 pitch prop should be putting more of a load on the motor than it does. My prop has been repaired in the past and I also had it repaired, so im guessing it has lost some diameter and maybe some pitch.

After re-reading this, I must concur with you. You must have lost some pitch or diameter with the prop work. NO WAY you are running the same speed and rpm as I am at cruise with a slip # of 26. Check your bolt hole height and get back. There are cover plates with two flathead screws on the sides of the motor. If you pull one of those off it will reveal which bolt hole you are set at. In regards to a cheap prop off ebay, as long as your rpms are accurate, there is NO reason to swap props. Your numbers are right where they should be.

When you do your fuel tests I have some good advice for you. Take the cover off while at home, move the throttle up until when the timer base contacts the MAX spark advance stop. Mark your throttle position on your controls. If your boat rides good and on plane at this setting, this will be (or at least very close) to the most efficient throttle setting on the boat. Max spark advance with the least throttle I havent verified the rpms at this setting, but Im guessing it is in the 42-4400 range

 

[jwall116]

Beyond prop slip my RPMS and speed #'s are there. I can not believe how little data there is to be found on our boats. I have a spec sheet I was able to find.

201 DC Neptune Sunbird
Length 19'9"
Beam 7'9"
Draft 28"
Fuel 64 Gal
Weight 2400 lb
Freeboard aft 13"
Freeboard Foreward 37.25"
Capacity 1200 lbs
Deadrise at transom 18 Degrees
Bridge Clearance 54"

 

[sutor623]

Yea not much info at all. I have also heard mixed reviews on them but I am very happy with mine. 20 yrs old and solid floors and transom. Let memknownthat bolt holes your motor is on. If it's higher than mine I am going to consider lifting mine as well.

 

[jwall116]

Futher testing and install of new flow meter is delayed. My fuel gauge now only reads empty. No power reads 1/2 and ignition on reads zero. Shorting out the sender unit doesnt move the needle. What model # sender did you install? The amazing manufacture installed the sended slightly off from the inspection hole so replacing it will be creative! but it is definitely the original.

 

[Fed]

If you're testing it correctly that would mean you have a faulty gauge, hope this helps.

 

[sutor623]

Yep follow Feds instructions. I got the reed style sending unit from RDS aluminum. Just give them the model number off the tank and they'll send you the right sender. Now, putting in the reed style will be a little difficult if the hole isn't just under the inspection port.

I actually pulled the whole hatch up when I cleaned my tank, and positioned it as forward as I could to move weight up as far as I could, and made it so my fuel sender and tank line were just under the hatch. That hatch is just held in with 12 screws and no adhesive. It's just a foam gasket. Then you will see the wooden stringers in there and can see what kind of shape
They are in. Let me know if you need any more info.

 

[jwall116]

No Title

Except my gauge has 4 post. What are they?

The fuel gauge is the one on the left.

 

[Fed]

The drawing also has 4 connections. S I G L
Sender, Ignition, Ground, Lamp.

Remove the wire from the S terminal which appears to be the bottom one.
Turn on Ignition and the gauge should peg out at zero.

Jump a short wire between the S and the G terminal and the gauge should peg out at Full.

If you have a meter handy make sure you are getting 12 Volts between the I & G terminals, I'm taking that as a given.

The back of the gauge should have these letters molded into it so check & confirm.

 

[sutor623]

I was talking about the sender (in the tank) when I referred to the 5 bolts.

 

[jwall116]

Thank you for the help with the fuel gauge !! It turned out to be a broken ground wire at the battery (the sender is wired directly to one of the batts). Installed a new connector and back in business.

I also installed the fuel flow meter today, didn't drill it into the dash and don't think I will..... being that it is a discontinued device I am leaning towards installing into a gauge pod and putting it where the compass is. Who the heck needs a compass with cell phones and chart plotters!? HA Really though, has anyone used a gauge pod from the internet/auto parts store on their boats?

As for the prop, while I was at the Houston boat show last week I noticed all of the props had a much thicker leading edge than my prop. Maybe thats a stiletto prop thing, or mine has been repaired multiple times. This would explain the shallower bite and slip I am experiencing. If this one becomes damaged it will be replaced with a 15X17. Even the Worst Marine prop wizard says to use 15X17.

NOW!!! I am heading to the lake to test out the fuel flow meter! I will report back later after i'm done having fun.