Engine cranks slow, but batteries are charged

[nemo]

Last weekend I took the kids up to the lake to motor them around with the tube. Had a great time with the Suzuki 70 which could pull them at about 20 mph, according to GPS, with no water ballast. After about 3 hours of this we shut off the engine for a while so the kiddos could do some diving off the boat. When I restarted the engine, it barely turned over as if the battery was low. On the 3rd try it finally started, and we brought her in.

So why didn't she crank fast as usual?

The boat is brand new this year, and so are the 2 batteries. These are wired up with a battery combiner which theoretically saves one battery for engine starting. I have a voltage meter wired in that shows both batteries are fully charged, which I would suspect after 3 hours of motoring around.

So I suspect a loose, high resistance, connection somewhere between the battery and starter but can't find anything obvious. What else could it be?

Have anyone come across this problem? Any ideas? thanks -

[Timm Miller]

Has it ever done this before? Does it spin up better if it is cool? You might be on the right track with the connection idea. What is your voltage reading at the starter? Is it possible the starter is going South? What size wire do you have going from the batteries to the outboard? It's going to be something simple.

[Moe]

When checking for loose connections, not only ensure the ring lug on the end of the cable is tight on the terminal, but tug on the cable to see if it will pull out of the ring lug. Kids around the transom is the first place I'd check, i.e. the terminations of the cables just inside the motor. One could've tripped or stepped on a cable and possiblly pulled it out of the lug or damage the attachment point inside.

[nemo]

Thanks for the ideas. It had never done this before and I haven't tried since so don't know if it was just an intermittent thing. Everything is brand new. I need to pull it out of the garage and do some driveway testing (while running water through the engine, of course).

In addition to your suggestions, I want to watch the voltage at the battery while cranking.

[Catigale]

Nemo - when you say the voltage meter says your batter(ies) are charged can you be more specific? Static voltage doesnt tell you much about the state of the battery imho.

[Jeff Stagg]

Hi Nemo,

Short version:
Fisrt, check your oil. If recurs, turn off everything else and try again. Still recurring, check connection at transom inside boat and terminals at battery. Still recurring, try wiring only motor directly to aft battery without combining on a switch. Still recurring, warranty time?

Long version:
I have a '98 X with standard battery in factory position by companionway and group 24 "house" by forward vent under V-berth; they were wired with a Perko selector switch. This year I separated them so only the motor is on the aft battery, everything else on the forward battery, no more switch.

I charge my batteries at home before each trip, but now have found the starter battery doesn't need any charging since it is charging when motoring, and not being drained in any remote way by the house wiring demand or the other battery. I read (West Advisor?) somewhere that if batteries are combined and one battery is weaker, it will absorb juice from the other battery until they are balanced; I don't think this applies to your situation, but it may be part of it.

I'm no electrical techie, just telling what happened. From the beginning (before separating), I found that if I tried to start the motor with the forward battery, even though bigger, the longer run to the motor affected the turnover rate. After an overnight of stereo and lights (incl anchor lt), it wouldn't turn it over, but the closer battery would normally still work. Main point is that when both batteries were wired as combinable (through the switch), my motor turned over very slowly almost all the time as if the battery was weak. I'm on my second set of batteries, same result. Since you have had good turnover, I can't explain this, especially knowing your motor was charging the battery while under power for three hours.

My guess is something's wet or loose, or some juice is zapping it. My Mac came with a taped splice connection at the transom inside and sat where water could sit. The connection is copper to stainless and if there's any green, it's electrolysis. I used sanpaper after some light filing to shine them up again, also at the battery connections.

Before separating my batteries, sometimes I couldn't start the motor if the stereo was on, even the fishfinder would interfere somehow, and that's not much demand. Hasn't been a problem since I wired only the motor to the starting battery.

One other problem I suffered from January to May was intermittent no starter due to the shifter not popping into neutral, locking out the ignition. I thought it was electrical after all the problems I had been having, and that's why I re-wired my boat through a second circuit breaker instead of ganging all the stuff onto a bolt and then to the battery. Point is, that didn't help the starting, and Jeff Mott at Arena Yacht Sales (my dealer) narrowed it down to the shifter/ignition lockout for me on the phone.

Although I have replaced the throttle cable twice, I have the generic original (non-Yamaha) shifter cable, and the shifter was hanging between reverse and neutral when in neutral position since that's how I dock the boat (power forward parallel to dock just upwind two to three feet, then place in reverse and turn wheel so stern pulls toward dock, lean over side and wrap line around the cleat, let motor cool if hot while tying off bow. If downwind or downcurrent, after tying stern to dock, place in forward and turn wheel so boat steers into dock, similar to Roger's powering onto trailer and going forward to hook in factory video).

On the ignition lockout, I unhooked the cable inside the pedestal and made sure it wasn't binding, then at the motor, found it was binding, and lubed the track it moves on and adjusted the locknut on the cable. Once in a while I still have the problem, but not if I move the shifter (motor on or off) into forward then to neutral. Having had a tune-up at the Yamaha dealer, he lubed it some more. I highly recommend you take a digital photo of the pedestal and motor cablel assembly before undoing anything.

If your motor is locked out of the ignition in this way, you can still pull start the motor (which I did many times this Spring before finding the fix) since it bypasses the starter lockout. I can hand start my motor with less effort than my lawn mower, just a hassle dealing with the cover.

[Robert]

If there is a penetration through the wire's insulation that salt air or water can get into, the wire inside the insulation may be corroding away out of sight. If you have proper marine wire, it will be tinned all the way to reduce the chances for corrosion. Just thought I'd add my 2 cents. I had this corrosion inside the wire problem once with an old car, all connections were great, but the wire between was bad.

[nemo]

Nice responses - much appreciated. To answer some..

I was measuring just static voltage - looked like about 13 volts. I was out with only small kids so couldn't get them to accurately describe what the meter was doing while starting the engine (ie voltage droop). Here's a picture of my battery meter located near the ladder..

http://www.brownz.com/power_gauge2_2.jpg

Next time this happens, if it does, I'll have someone watch that meter while cranking. If it doesn't droop much then I'll know the voltage drop is not a weak battery but perhaps a bad or not fully engaged switch (high resistance switch).

Jeff brings up an interesting point that maybe I just needed to wiggle the throttle lever to make sure it was fully into the neutral position - perhaps I had a high-R connection there.

So last night I hooked up the hose to the engine and fired it up several times. It was snappy every time - and I have not charged the batteries since that trip, and only motored for another 10 minutes after the hard starting event. So all I can do at this point is suspect it wasn't fully into neutral, or I have a slightly loose wire that I haven't discovered yet. By the way, the boat has never been in salt water.

I don't have the habit of charging batteries at home each time - maybe I should.. With the combiner, I'm not supposed to have the issue of lights, etc.. draining the engine battery so I haven't worried about it, and it's always just worked.

One thing I discovered last night, and which Jeff also points out, is that this engine can be started with a rope. I didn't think it had that capability but found that it theoretically can be done. I've never pull-started a 1300cc engine before, but if that's what was required to get going I'm certain I could.

Thanks again for your ideas,

[Don T]

Hello:
I have some testing ideas for you. If you have a VOM, try measuring the voltage drop when cranking. If you have a bad connection or wire it will show up. Measure the voltage drop by puting the VOM across any component. Ex: put the pos lead to the + battery post and the neg lead at the starter + terminal. When you crank, The VOM will show how much voltage is being lost traveling the distance and through the solenoid / relay. Check both the pos and neg cables. If the VOM shows more that 1 volt you have problems. You can isolate by checking each component seperately.

Also, it is not uncommon for a failing starter to draw excessive current when hot. So, the decision has to be made as to whether the starter draws too much current causing the voltage to sag (batt volts drop too) or whether the voltage drops due to resistance in the circuit (batt volts stay up - volts at the starter drop). Either occurance will generate the same symptom - slow cranking.

Deciding whether the starter is bad can be difficult too. Electric motors draw more current the slower they spin. So, if the voltage is dropping due to resistance in the wiring, the starter will draw excessive current. This becomes difficult to determine when, as in your case, the problem is not accute. It easier to find a burnt connection with a total failure that it is some resistance in a circuit causing an intermitant problem.

I hope I haven't totally confused you.

[Chip Hindes]

Don't know about pull starting your 4S 70, but with my Tohatsu 2S 50, I had the "opportunity" to pull start it for the first time ever in Bimini this summer, when both my 5 yr old batteries decided they were done with their lives.

Well, here goes nothing, I thought. I removed the hood and top cover, wrapped the starting rope around the flywheel as many times as it would go, turned on the key, pulled the manual choke, grabbed the wrench I had tied to the running end of the starter rope with both hands, pulled it just a little until I felt some compression resistance, then put both shoulders and all 220 lbs into a heroic pull on the rope.

The motor fired in about the first four inches of rope travel and those same 220 lbs were deposited face first on the starboard side cockpit seat. Fortunately, I was at anchor rather than docked and in the early morning nobody had a chance to observe the tumbling routine

Probably 8 or ten more times during the trip, it started first time, every time, quicker than with the electric starter, and way easier than my 4HP 4S dinghy motor. Though one caveat; I found it's easy to forget to turn the key on. It absolutely won't start without it

[Daves_knot_here]

Nemo,
Where is your Raymarine DS 400 wired into? It has the capability to display battery power level on screen. I wired mine into starter battery so I could monitor charging and discharging voltages. I know many of you do not think this is a good idea, but my X has three house batteries and the ability to use that bank to start the engine if needed. So far I have never needed to use the house bank.
Dave

[Frank C]

... then put both shoulders and all 220 lbs into a heroic pull on the rope.

The motor fired in about the first four inches of rope travel and those same 220 lbs were deposited face first on the starboard side cockpit seat.

(at the description, not the event)!

I don't want to try pull-starting my Suzuki DF-60. Have not read-up on this topic, but one reason most EFI motors have big alternators (21 amps, my case) is the brute of a fuel pump required to feed them. I'm just wondering if pull-starting is possible without some residual electricity to fire those injectors.

I always take the little jump-start battery on the boat. Two bilge batteries plus that backup should always get it going - if not, always got the sails.

[Jeff Stagg]

Nemo,
From your post I think you misunderstand what happens when the shifter doesn't "click" into neutral even though the lever appears to be in the right spot. It's the same as trying to start the motor when in forward or reverse: lights on the tach and tilt meters, turn key, nada, zip, no sound, no motor starting, no nothing. This is different from cranking slowly. In a panic when I first bought the boat I turned off the key when the motor was in forward after I had raised the sails and left it there. Later after lowering the motor and turning the key, it was still in forward and only after runnning around checking wires and fuses I grabbed the shifter and realized it wasn't in neutral. It's like losing your wallet and then finding it on the driver's seat...

My Yamaha has an in-line fuse inside the case that goes to the starter or ignition, as well as a fuse in the pedestal. The one in the motor blew one time. I carry spare fuses of all amps in my parts kit....also have found a stereo in-line fuse with bad contacts that was causing an incomplete circuit even though the fuse was fine. Twist the wires and make good contact with the fuses if troubleshooting.

Since we often refer to our motors as "Iron Genoas" maybe your motor was just plain tuckered out from the three hours of tubing Intermittent problems are the worst; hope you're good to go.

I've become interested in the volt meter discussion and how to test, thanks to all.

[Catigale]

My Mercury BF 50 EFI pull starts pretty easily, Im the same 220# as Chip but deposited myself portside when I tried it first time.

EFIs need 12 V nominal to to turn on the brain in the engine, but if even if you leave everything on and run your battery down to 'dead', if you turn everything off for a few minutes you will get enough voltage to make it work. Hand pulling removes the starter load of course, so you dont get the voltage drop when cranking by hand.


BTW, a 80 amp hour 12V nominal battery has roughly 960 Watts capacity, so a 200W alternator would take 5 hours to charge from near dead per battery, assuming you were at sufficient rpms to get the 200Watts

ANyone have an alternator vs rpm production curve??

[Moe]

I may have posted the actual numbers here before, but IIRC, the Merc BigFoot EFI only needs about 6 volts for about a couple of seconds to pressurize the fuel injection system for pull-starting. Dunno about the Suzuki DF50.

The battery internal resistance to current in the charging direction rises with the charge and as it does, the charging current goes down. It's pretty linear until it gets up to about 80% charge, then it can take as long to go from 80% to 100% as it did from 20% to 80%.