Evinrude 140 hp V4 prop

[Jsted19]

I just recently purchased a 1988 Grady Offshore 24. It had twin Evinrude 140 V4s on it that seem to be in pretty decent shape so I figured i would run them till they died. I was wondering if anyone had any experience with them or any problems i should know about. I know they have pretty terrible mpg's and gph but i was wo dering if anyone had insite on best prob for fuel economy. Speed isnt really a concern for me as much as fuel economy. Any help is greatly appreciated. And I am glad to be apart of the family.

PS I fish out of the outerbanks area so if anyone want to help me get started on where a few decent spots are that would be great mostly Oregon inlet or Chesapeake Bay. I have the tripple 0's numbers but Im an army vet asking for a friendly help. Im willing to give ny email phone number or meet up hell even possibly go fishing with you to find the fish. Jsted19@gmail.com is my email or look me up on fb justin steddum.

 

[DennisG01]

Since you didn't mention it, is it safe to assume that the engines are 1988 models?

 

[Jsted19]

To the best of my knowledge yes they are either 88 or 89

 

[DennisG01]

OK. Then as far as MPG goes... just assume "not that good" Heck, no boat gets "good" mileage. I think a safe guess - to get you started - would be in the 2mpg range. Once you run it a bit you'll get a better idea.

What is "best prob for fuel economy"?

 

[Jsted19]

I mean I know its going to suck I am asking who has looked into getting the best possible with the setup. I know there is many different variables like weight, seas, speed, ect but I want to know with someone that has used it for fishing what was the prop that provided the best overall fuel economy with this setup

 

[DennisG01]

You're searching for a needle in a haystack. It's a very uncommon setup. "Fishing" has nothing to do with it - unless you're talking about a trolling and in that case, it still really doesn't matter. The most efficient, overall, setup will usually be a 3-blade and one that allows your engines to get well into your WOT operating range for your engines. There is no such things as "best" - it's what works best for you, not for someone else. Put some props on there and go play - or talk to a good prop shop. In person is usually best as they may have a trial program, but a well known place like Prop Gods is a good source.

Edit: Forgot to add... what are your current speed/rpm max numbers and what is the rpm spec range for your engines?

 

[Doc Stressor]

I blew up 2 of those old loopers on my '75 Overnighter. Be sure not to over prop them. I had the best results with a 15' prop on my single engine setup that would let me turn 5500 rpm empty. Both failures came with 17' props that would only turn 5100 rpm. Wrist pins both times. Once after giving a guy a tow and the other after carrying 9 people out to an island for a party. I could get a little over 3 mpg with the 17" props, but they couldn't handle a load.

They were actually very reliable engines for the day. The only other thing that failed over 11 years was the voltage regulator a couple of times.

You might be able to get 2 mpg with your setup if you can stay on plane at 4000 rpm or less. But you'll probably get closer to 1.5 mpg under normal running conditions.

 

[Jsted19]

Thanks Doc very helpful

 

[Jsted19]

Update finally got to run it today. The props on it currently is aluminum 14.5x19. Didnt get to run it far only about an hour so I am not sure about my MPG yet but my port motor is stronger then ny left motor. WOT is around 5100 or 5200 RPMs with it trimmed to position on plane. I took it out the other day and the port motor kinda cavitated at 2500 rpms.but think it wasnt trimmed down all the way. This time it barley did it for a split second and trimmed them down and it was fine. The r
Starboard motor kinda struggles to rpm up but it was running about 4500 or 4600 RPMs WOT. With the throttle set to where the motors matched a good cruising rmp was around 4100 for both and they sound and feel good just finishing up the kinks here and there and she will be ready for offshore. Still looking to buy new props though. My buddy said buy aluminum Turing point 4 blades but dont know what numbers to get not sure the size on it is best. What do you all think?

 

[DennisG01]

It sounds like you might be new to trimming engines for hole shot and Max speed - as evidenced by getting ventilation (not cavitation) a few times from not being trimmed all the way down for take-off. Nothing wrong with that - just need to know what we're dealing with to best help.

"Trimmed to position on plane" isn't clear. As asked above, what is your Max RPM (Speed if you know it, but not as important) and engine RPM specs? Do you know how to achieve Max RPM... or, how did you do it?

 

[Jsted19]

So I am somewhat new to bigger boat trimming but I an 18ft hydra sport bass boat that I owned for years. So newish I would say.

Motor was trimmed all the way down for hole shot. Took about 10-12 seconds to get up on plane and my rms in hole shot was 4200 on port and 3600 on starboard with WOT. Once on plane i would trim the motors up a hair to level the boat out at WOT the rpms were what was stated in the last message. Not sure speed as I didnt have the GPS on today. Those in previous updated reply was MAX rpms. I am unsure as to what you mean about Engine RPM specs. Sorry about not knowing how to answer your question like i said kinda new to this world used to bass boat in the lake not a big grady. Thanks for the help.

 

[Jsted19]

The trimming on plane was to achieve max RPMs

 

[DennisG01]

OK - now I understand where you are coming from a little better. That explanation helps. To get Max RPM, you need to be going WOT (which you are already doing). BUT, continue to trim up a little bit at a time till the speed no longer increases or you start to ventilate. Tap it back down a bit and try again. This should, obviously, be done in ideal conditions and a light load. This keeps the variables to a minimum - which is very important as we can only give advice based on what you tell us... meaning, ideally, it would be a whole lot easier to figure this out if we were there with you.

Engine specs... find out what the Max RPM range is for those engines. This is a very important piece of information. "Sometimes", it's printed on a tag somewhere on the engine... but not always. Google will be your friend here.

 

[Jsted19]

Okay so this is how I achieved the max RPMs qas by WOT and trimming to max RPMs.

Load was nothing in boat except myself 190lbs, and 2 buddies roughly 170lbs, and 230lbs. And a full main tank 96 gallons of fuel. Calm water light wind.

I am not currently home to look for RPMs on motor but for the last 2 weeks I have been replacing all fuel lines and cleaned carbs twice and havent noticed anything. As far as googling not to much help either. Just other forums.

Motor info 1988 Evinrude 140 V4 looper TXCCM
I believe M is the last letter but not 100% only about 85% as to im working right now. Hopefully that answers more questions you had.

 

[DennisG01]

Keep googling - it's gotta be out there. I would "guesstimate" that the max is likely at least 5500, if not 6000. If you're planning on wrenching on your motors - get a service manual - it's a good tool to have and will also give you engine specs.

Just to be clear... you kept trimming up till speed no longer increased or the prop ventilated?

Can you clarify what you said above... it's not clear: "my port motor is stronger then ny left motor. WOT is around 5100 or 5200 RPMs with it trimmed to position on plane. I took it out the other day and the port motor kinda cavitated at 2500 rpms.but think it wasnt trimmed down all the way. This time it barley did it for a split second and trimmed them down and it was fine. The r
Starboard motor kinda struggles to rpm up but it was running about 4500 or 4600 RPMs WOT."

Does this mean... Max RPM for Port was 5150 and the Stbd was 4550?

Let's get the details nailed down and clear and then we can take a look at things in more detail.

 

[Jsted19]

Trimmed till rpms was maxed not ventilated and the max RPMs was roughly what you repeated from what i said before yes. The max RPMs achieved at WOT for each motor. And im still looking for specs

 

[DennisG01]

OK, you said "my port motor is stronger then ny left motor." Port "is" left. So just wanted to confirm if that was a mistake in writing/proofreading, or if you meant something else.

When you get out again, keep trimming up till the speed no longer increases or it ventilates. Take a quick run to do this with just you on board.

AS a side note, I would expect your top end speed to be somewhere in the 40mph range with everything healthy and proper. That's right about what I get.

 

[Jsted19]

Oh yes sorry the port motor is stronger then the stbd motor as the rpms are higher and more powerful with the port motor. My apologies lol. And will do. Props on the boat are not in the greatest condition very mild rust on blade edges but other then that good condition. That is why I plan on replacing and just wanted to get info on what prop size has been successful with other boats for best combination for the best GPH fuel economy as ill be doing offshore trolling.

 

[DennisG01]

A little bit of rust won't affect performance - certainly not to the extent that would be noticeable. If that's all you mean by "not in the greatest condition", I wouldn't worry about that. Certainly, the props could be out of tune/flattened out. But that would INCREASE RPM's.

Is one of your engines counter rotating?

Something you can check... look at the throttle linkage on each engine and compare how far each travels - from the neutral position to fully open. You might get lucky that the stbd motor's throttle just isn't opening as far as it should.

 

[suzukidave]

i run a 1985 120 johnson v4 looper on my 190 tournament that is original to the boat. great motors. in my experience they use a lot less gas than a 150 carbed v6, so unless you are ready to move up to a direct injection or 4 stroke motor or maybe convert to a single motor, there is no need to change them.

one comment.

if one motor is 500 rpm behind the other that is a big gap and it may be running on 3 cylinders. my motor can get over 4000 rpm on 3 cylinders. with a second motor helpig i can see it getting to 4600 rpm i would stop running it and figure that out because if it is a fuel issue in one carb then it could cause engine damage since the oil in the fuel is what lubes the cylinder. start with a compression check on the 4 cylinders. a compression test is very easy on these motors. remove all 4 sparkpugs. insert compression tester into one cylinder. push throttle forward. crank engine for about 15 seconds. take reading. repeat. if your readings are over 120 and close then next check for strong blue spark on all 4 cylinders. if that is good too then you may want to have your carbs cleaned and rebuilt or at least checked for synch.