Bass Boat Starting Problem.....Ideas?

[Mike 12345]

Hi folks-

I have a problem starting the 'big ' motor on my bass boat, and wonder if any of you can help me diagnose it.

First off, it is a 1991 Merc Black Max XR4 150 HP motor. When you first start it at the boat ramp, you can get it running and move out into the lake fine. It will run great........then you stop to fish. Troll around, fish, trim up when you get shallow, etc. Once you are ready to leave, you position the boat into enough water to safely start and run the big motor....and you engage the ignition and crank. (I don't crank too long- no more than starting a car). No dice. Try again......won't turn over. Repeat appx 4 times, and then it won't even crank at all.......it is as if the battery is totally exhausted, and the engine never even gets close to starting.

Thank goodness I was reasonably close to the ramp and I had fully charged trolling batteries.

I bring the boat home, put my charger on the starting battery. It charges for about 3-5 min., and shows a full charge.???????

(by the way, it is a brand new battery, on its first trip to the lake....showed full charge when I left home).

The same thing happened on the last trip of 2007.

I just don't get it......why would it start fine at the ramp, and then no other time? >

The previous owner told me to prime the motor before every start, and it used to work fine that way...until the past two trips to the lake. I've wondered if I was flooding the motor, but why would it work before and not now if that were the case?

Any help would be most appreciated.

[_tyler_wright_]

This happened to me and my uncle the other day in his bass tracker. It turned out to be his battery. Just take your battery back since it's new and get another to replace it

[NBR]

Have the battery load checked. Wally World can do it if you have no other choice.

[BassinDave]

If not the battery, it may be that the starter draws too much current when it gets hot. Could also be a bad connection at the battery, starter, starter relay. Also check the grounds. But i would be sure the battery is good via a load test. Good luck.

[Glenn]

Begin with the simple stuff first - I suspect with a '91 engine, your boat is circa the same year?  If so, check that your kill switch is working.  A partial or faulty connection (either via a loose wire or loose switch) will cause that problem.  Ensure the switch is fully up - by physically checking it (don't just look at it) - before attempting to start the engine.  If it works, replace the switch.

Then move to the batteries - again, check the connections and wires first, before spending the bucks on new batteries.  It could be something as simple as a loose connection.

Hope that helps!

[Garnet]

Clean your battery post and wires and also at the starter.

This motors a 91 so carbs? When you turn it over step on the gas if you have a hot foot.

Garnet

[Mike 12345]

Thanks for the tips guys, I appreciate it.

Here is another thought I had on the matter-  since after a couple of ignition attempts, nothing at all happens (no cranking, no noise, just a click) would it seem possible that it could be the starter solenoid  that is bad?

If it were bad, heat damaged, etc, would that possibly explain why the motor would start at the ramp, but then not after being on the lake?

I'm just trying to mentally picture the system, and it would seem that if current was getting all the way to the starter, it would try to turn the motor over.

This is an attractive possibility to me because A) I could replace it myself, and they are under $20

Again, thanks ....I'm trying to troubleshoot simple stuff first, as you all have mentioned.

[NBR]

Mike.

If your boat is like most you run every thing on board except the TM with your cranking battery. I have experienced similar problems. Put some muffs on your motors and jumpers either to your TM battery or get your car close and run jumpers to the boat. I had to replace a starter solenoid several years ago and I think it was more than $20.

Keep us informed.

[Mike 12345]

Hi guys......I just wanted to update the thread to include the information that the battery tested fine, and the shop that fixed the boat found that it was a rectifier relay or regulator relay, one or the other.  They say rectifier, the parts box says regulator.

It was not a cheap fix, but I'm back on the water.

Evidently this is a critical part of the charging system that allows the engine to put back charge to the cranking battery while underway.

Just wanted to update in the event anyone else witha similar problem was searching for info.

Thanks to all-

[Splat]

A rectifyer is used to convert AC current (like off of your stator coil) to DC which can then be used to charge your batteries.

A regulator adjusts how much DC voltage is fed back into your batteries. Neither item would cause a NO Start condition that I'm aware of.

Didn't you post your batteries would not accept a charge when you got them home? Did you get the old parts back?

Dosn't sound quite right to me. But if it works, who cares.

Bill

[Mike 12345]

The batteries would recharge once home, but the issue was that the cranking battery would be depleted enough after getting the boat started initially, running the spark plugs while underway, then running electonics while fishing, it did not have enough juice the get me going again to get home. It was not getting any (or enough) charge back while underway to keep it up.

I did get the old part back- it is flat-ish, square, sort of like an enlarged deck of cards with wires, and the box says regulator assy.

Long story short, everything seems to be working normally now, and there have been no probs to report recently.