WHat speed should I be getting

[dtnel]

I am trying to figure out what speed I should be getting out of my 1990 Evinrude 48 SPL E48ESLESA motor? I know the prop and other factors add into the equation. With my son 160lbs and I 270lbs using the GPS app and full fuel, 12 gal we're only getting 24-25 mph using a GPS Speedometer app on the Motorola Droid Razr Smartphone. Does thius sound normal? I still have yet to pressure test the crankcase once I find my new pressure test gauge that I misplaced inmy garage. ANy and all help welcome.

 

[AEROCOOK]

Re: WHat speed should I be getting

What is your WOT RPMs?

 

[Levinz11]

Re: WHat speed should I be getting

My friend has a 15' Eagle fish/ski with the same motor. He gets 25 with two people aboard as well.

 

[Tim Frank]

Re: WHat speed should I be getting

I am trying to figure out what speed I should be getting out of my 1990 Evinrude 48 SPL E48ESLESA motor? I know the prop and other factors add into the equation. With my son 160lbs and I 270lbs using the GPS app and full fuel, 12 gal we're only getting 24-25 mph using a GPS Speedometer app on the Motorola Droid Razr Smartphone. Does thius sound normal? I still have yet to pressure test the crankcase once I find my new pressure test gauge that I misplaced inmy garage. ANy and all help welcome.

Bit of a time waster trying to start with what you hope is the correct answer and then work at achieving it.:facepalm:
You need to work with your actual setup, make sure it is optimised, and that will be all you are getting.

You haven't mentioned what boat you have, or why you think a pressure test is necessary. Just having the tool isn't really a justification.
What RPM are you turning at full throttle?

 

[dtnel]

Re: WHat speed should I be getting

My mistake on mentioning the model info, etc. I guess you call it a rookie mistake which I can accept given the learning curve involved as I've found on other topics such as rebuilding the lower unit a week after I bought it with no Marine experience whatsoever. ANyway back to topic.

The reason i wanted to pressure test was I've read that's something that should've ben doneprior to buying the boat, rookie mistake but I still need to do.

RPM gauge don't work, along with the speedometer. I guess that'll be a offseason fix this winter. Links for troubleshooting can be posted if anyone has any direct ones.

The boat is a 1992 Northwood 160 Pacer which the more digging I've did I've found was manufactured by Brunswick Marine from Napanee In from the best I can tell on the NMMA sticker which is severely faded to the point I can't tell capacity info, etc just the last letter of Brunswick, "k" , the word marine and Napanee IN in which a gentlemen at Smokercraft who's been there since 1986 told me based on the serial number beginning with BKK that they didn't make it.

The motor isn't the original motor either. Still working on getting pics up.

There's alot of work planned for this boat in the off season in my garage, i.e. flooring, carpet, electrical, stereo, key assembly, and other small misc stuff due to the age of the wood and it showing more and more wood rot the more I poke around.

I'll be install,ing a transom ladder in the next couple days for the kids to hop in and out of boat on when wakeboarding as I've quickly found they like that and I fish so it's plus for the family as mom takes photos and videos since she don't do either.

It's a Aluminum V hull, Fish/Ski Style Boat I presume?

I did also notice a little black stick thing at the rear of the boat on the starboard side that has a wire that leads up to console has been ground a little bit from maybe rubbing the lake, river floor? My guess is this is related to speed ?

I don't know my prop size yet either. Is there a quick way to tell what size prop I have?

I know this is alot and some of the information here is tied to other threads I have posted as well. I'm beginning to realize I bought a mechanics special but hey I think that's me as I use to work on Class 8 trucks and have repaired most stuff on my cars, lawnmowers, camper, my house, etc through the years....

 

[Chris1956]

Re: WHat speed should I be getting

Prop size is usually stamped on the prop somewhere. You are interested in the prop pitch and condition. That speed is a bit low, but not a lot low, and could be related to type of hull and weight in boat. I doubt you will see 30MPH, but you might see 27 MPH.

 

[belairbrian]

Re: WHat speed should I be getting

I'm running a 1989 Johnson 48 SPL on my15 foot aluminum hull. Ran a speed test on it this weekend. Me 215 lbs son 140 lbs and about 9 gals fuel. 2 batteries. Highest sustained reading was 35. But a bit bouncy, eased back to 32 and it was smooth. Planes very fast. Ordered a tach so I will soon have WOT readings. But those will just be informational as I am happy with the way the boat performs.

Here is a pick of the boat to give you some reference.

 

[dtnel]

Re: WHat speed should I be getting

I have plenty of work to do over this winter motor and hull wise due to the years of neglect the boat faced as is somewhat evident. Will be posting pics here and there in different threads over time. I do ned to get a weight on the boat which I'll do at the truckstop sometime then weigh the trailer without the boat sometime when I'm near a dock or marina that has a truckstop with a scale nearby. I'd guess the mfr knows what the trailer weighs. It's a Shore boat trailer with a spare tire.

 

[AEROCOOK]

Re: WHat speed should I be getting

In order to properly dial in the boat / motor combination for optimum performance you will need a working tach. The motor must be able to reach the specified RPMs at wide open throttle (WOT). If you have a prop with too much pitch the motor wont be able to achieve the required RPMs which can reduce your top end speed and more importantly it will damage your motor over time. If you dont have enough pitch the motor can rev too high and speed can also be affected. The guys over on the Prop Forum are excellent and I'm sure they will help you get it dialed in.

 

[TrueNorthist]

Re: WHat speed should I be getting

Here's a cheap and effective tach. You can get them at just about any small engine parts store. Works very well too. Just hold it on top of the motor and dial the wire out until it vibrates the most and voila!

 

[belairbrian]

Re: WHat speed should I be getting

Here's a cheap and effective tach. You can get them at just about any small engine parts store. Works very well too. Just hold it on top of the motor and dial the wire out until it vibrates the most and voila!

That could be fun at WOT!

 

[dtnel]

Re: WHat speed should I be getting

That could be fun at WOT!

I'm still thinking of who's going to drive the boat if I'm back at the motor, JK.... Lol....


I think I need to get under the dash and given what other surprises I've had I wouldn't be surprised if there was a bundle of chopped wires as the fuel, speed and tach gauges don't work. I have test lights, multimeter's and wire cutters and crimpers so i think once I figure out what goes where I'll have my issues resolved.


I did notice on top of the flywheel there is white marks on the timing marks indicating this has probably been tuned here and there through the years. Will a common timing gun work on these 2 cycle motors? I'm sure I'll find out by reading the manual which I've been slowly working on but never hurts to have a quick answer to help me get even more motivated.


I'll try to find the numbers on the prop size. There was a 2nd prop that came with the boat and I was told by the sellers (early 20's age range) son that it was for speed and the one I have on is for torque. I'll try to get some pics of the props up later along with the power head so if anyone notices anything odd they may bring it to my attention so i can look into it as I'm green but willing to learn. I think that's why we're all here right??


here's the sub-album link to the boat pics I'v loaded so far,

http://photobucket.com/92Northwood160Pacer

 

[belairbrian]

Re: WHat speed should I be getting

Know where you are with teh dash. I rewired mine from scratch when I bought it. 30 years of patching and modding made it a mess.

 

[TrueNorthist]

Re: WHat speed should I be getting

lol. That would be fun on yer own. Maybe a good test of the steering? Hang ten! Seriously though, my Mrs weighs less than a soaking wet seagull and can zip back with that tach and take a reading almost as good as the next guy. A fella would have to be half mad to attempt a reading on your lonesome. Back here at my forified command bunker complex I have two modified aluminium garbage cans as a tank and can run at WOT and that is when that tach really comes in handy. Accurate to <50rpm, no wires to worry about and you don't even have to take the cowl off. I also have a Snapon electronic tach that simply needs to be pointed at a plug wire, but that cost me a small bundle so I don't recommend those much.

 

[richardgreen]

Re: WHat speed should I be getting

For reference I run a freshly rebuilt '89 48 SPL with the standard factory prop (17p I think) on a relatively light aluminum v hull runabout (450#). I get about 31 mph no problem with a full load (2 adults, 2 teenagers, dog, cooler, etc). With just myself and one kid in the boat we gain about 3-4 more mph.