Running only 1 engine at idle speed

[mkuzdzal77]

Hey everyone, I come here looking for some advice. Although I've been boating for over 25 years, I have never had a boat with 2 engines. I just purchased a 212x ( my first jet boat) and am wondering if I can run one of the engines at idle speed with doing any harm. I have a 45 minute river trip at idle speed in order to get from my dock to the lake. I was thinking of running one engine out and the other on the way back to keep the hours close and possibly same some fuel. I'm aware that at higher throttle it can cause serious issues, but I'm not allowed to go that fast anyway lol. I just don't want to put the engines at risk just to save a couple bucks. Any input would be greatly appreciated.

 

[Dave burke]

Probably shouldn't be an issue but if this is going to be a regular occurrence (and it sounds like it), I'd probably clamp off the water intake line or add a valve to it. Better safe than sorry.

 

[mkuzdzal77]

So other than the issue of flooding the non running engine, there should be no reason why 1 can't run alone. I was planning on adding valves and stopping the flow to be on the safe side anyway. I feel 1 should be enough to push me along and in theory should save me almost 1/2 the fuel which means more fun on the lake. If I'm missing something else please let me know. Thanks for the advice so far.

 

[Dave burke]

Makes sense to me. Not sure how much fuel you'll actually save but it's worth a shot.

That 45 mins must seem like forever!

 

[mkuzdzal77]

Oh, it is, but it's always worth it once I get there. I'm going to compare gph to see if it's worth the hassle or not. Thanks again for the advice.

 

[David Martin]

I would clamp it off or get a shut off valve like others have said...........the reason 5mph limit off engine floods with water..........3mph forward speed add a 2mph river currant and flow speed going through off jet might get you into trouble. Now on that fuel MPG if you are going 4mph on 2 engines turn one off and wait a min or 2 to see how much speed you loose.........then add that time on you 45min run. or bump up the throttle to get back to 45 mins and you might use the same or a little less fuel.................

My old physics teacher would say it takes X amount of fuel/energy to move X amount of mass/weight along a course/line in X amount of time.
Let me know how it go's at lease the gauge's can give you MPG or GPH........ my SX240 runs approx. 4 MPH both engines at low idle something tell me turn of one engine 1/2 thrust and I'll be around 2 MPH 45minx2 90 min run to bay. I might save a little fuel but the time line ouch. Bump up the one engine throttle to back the 4MPH and fuel savings will go.

Just a thought

 

[knoxboatin]

I always run in no wake zones in the no wake mode using the push button on the console, first position. I think it’s a little faster than a comparable outboard in idle but the jets need some juice or there is no steering. Running single engine on a boat designed for two, dramatically lowers the speed, not just half. Guess you will find out by experimenting, it’s not going to hurt anything at idle but does not sound like a lot of fun.

 

[Cobra Jet Steering LLC]

When running with one engine off at slow speeds just place the non running engine in forward this opens the reverse bucket and allows the water to flow through the pump with less resistance and that will prevent water from being forced from the pump into the cooling system .

 

[FSH 210 Sport]

I would clamp it off or get a shut off valve like others have said...........the reason 5mph limit off engine floods with water..........3mph forward speed add a 2mph river currant and flow speed going through off jet might get you into trouble. Now on that fuel MPG if you are going 4mph on 2 engines turn one off and wait a min or 2 to see how much speed you loose.........then add that time on you 45min run. or bump up the throttle to get back to 45 mins and you might use the same or a little less fuel.................

My old physics teacher would say it takes X amount of fuel/energy to move X amount of mass/weight along a course/line in X amount of time.

Let me know how it go's at lease the gauge's can give you MPG or GPH........ my SX240 runs approx. 4 MPH both engines at low idle something tell me turn of one engine 1/2 thrust and I'll be around 2 MPH 45minx2 90 min run to bay. I might save a little fuel but the time line ouch. Bump up the one engine throttle to back the 4MPH and fuel savings will go.

Just a thought

The physics teacher quote is spot on.

My best guess for a 1.8L engine at idle is consuming some around .5 gallons a hour, so in 45 mins that’s .38 gallons or roughly .75 gallons for 1.5 hours. But you’ll have to use more than idle to stay at the max no wake speed so a lot of the fuel savings will go away. It’s true that you could save some engine hours, but it’s at idle, not much wear going on at idle speed.

How many of these outings do you make in a year? How much time do you spend on the big lake?

Our boats have pretty small alternators, about 14 A of output at 3500 rpm, at idle speed roughly 7 A that’s not very much supply to charge batteries and supply power to your accessories.

 

[David Martin]

I like math FHS210 but Mkuzdza you do bring up a great point about engine off that could save more money for gas = more fun.
single engine idle out even bumping up RPM to keep time line the same might not save too much fuel, orbut it will DROP engine idle wear by 50%. Hears a story that might make you laugh but could save money for more fuel = more fun.

Sorry guys hears my story about oil and engine wear..........My boat used 27 hours 7 year old boat came with conventional OEM oil which made me pause 7500RPM engine on a 10w40 conventional. First oil change switch10w40 simi conventional sent OEM virgin....simi virgin and oem used oil to Blackstone. Changed plugs(start was a little better) and waited for the analyses.....the plug READ..... OMG 8 vary rich with 3 extremely rich plugs...I used this time to clean fuel injectors and use a voltage meter to check and OHM the both engines Pickup coils, Coils, ohm injectors, EMC output voltage Compression test, fuel pump PSI test and wright down all normal put findings in Service manual for future service. Sound like a lot of work but come on SITTING ON A BOAT on the water listening to good tunes, watching palm trees sway and a cold one in my hand and the wife is not yakking in my ear THATS NOT WORK THATS A VACATION. Anyway the oil analysis came back 5 times normal raw fuel in oil but wear metals extremely low. OEM did its job................the simi came back another time No change in metal wear and Last the Full synthetic (my 3rd oil analysis this marine oil had more anti wear 3 times the moly and I had to take out a lone to pay for it..............You guessed no metal wear change, back to my low cost Simi synthetic oil for me.

I called Blackstone(3 weeks for the last oil check) I wanted to check if they got my oil, Blackstone went over analysis on the phone(nice guy) He ask me did I learn anything, I said yes my dad always said motor oil is motor oil and my long IDLE TIMES cause my wear not my oil choice.......I swear I could hear the office staff laughing in the back ground. Hope this story made you smile and lets change this theme to THINGS YOU DAY SAID THAT YOU NOW KNOW ARE TRUE.

Motor oil is motor oil
Never trust a politician(OMG dad you have know idea)
Last and I now know my dad was laughing at me on my first boat purchase 43 years ago............SON DO YOU HAVE MONEY BURNING A HOLE IN YOUR POCKET ON...... Ouch!!!!!LOL

So come on guys what did your dad say? that now makes you smile.

 

[Murf'n'surf]

I think that you will find that the steering will be very squirrley with one motor at idle speed. You are going to need some speed to counteract wind/waves/current and maintain course without constantly adjusting. At least that is my experience, but conditions will dictate what is necessary.

 

[Bruce]

Lots of great comments so far.

For the steering issues alone I would say no to this. Twin engines give our boats excellent manuverability but running on one engine is no fun always having to steer toward the running engine and loosing ability to turn in that direction.

Also you will need to throttle up and likely keep your hand on the throttle to keep it in a range where you will reach max no wake / 5 mph on one engine.

Try it and see how it works for you. Make sure that both engines are in forward so the reverse bucket is open on the non running engine.

 

[mkuzdzal77]

I'll let you guys know what I find out. Probably gonna be a bit as I'm not even going to attempt it until I put valves in.

 

[anmut]

Personally I wouldn't do it, and the reason is: when you go to sell that boat, you're going to have two wonky engine hour numbers to have to explain to the next buyer. Even if it's completely legit, it's going to be suspicious to the next guy.

 

[Julian]

Hey everyone, I come here looking for some advice. Although I've been boating for over 25 years, I have never had a boat with 2 engines. I just purchased a 212x ( my first jet boat) and am wondering if I can run one of the engines at idle speed with doing any harm. I have a 45 minute river trip at idle speed in order to get from my dock to the lake. I was thinking of running one engine out and the other on the way back to keep the hours close and possibly same some fuel. I'm aware that at higher throttle it can cause serious issues, but I'm not allowed to go that fast anyway lol. I just don't want to put the engines at risk just to save a couple bucks. Any input would be greatly appreciated.

I've done this when I wanted to troll for fish slower than two engines idling would allow. Ideally if you plan to do this on a regular basis you will want to add shut off valves to be totally safe. The only problem with that is REMEMBERING to turn them back on!

 

[Adrian @ JB Solutions]

If you're considering running one engine just to save gas - a new boat probably isn't for you.