Weak starting cranks

foolproof · Jun 12, 2012

What engine do you have, gas or diesel? Sometimes diesels have some trouble cranking, and you have to pull the decompression cable to allow it to crank.

dj2210 · Jun 12, 2012

Check your electrical connections at the battery and starter. I had a problem with my starter at the solenoid on my C27. Took it apart and cleaned and rotated the connections. On another boat I had a problem with the ground connection to the engine.
On my newly acquired C30 I also have to use both batteries to start. I don't know the age of the batteries but will be checking my connections first.

mortyd · Jun 12, 2012

if it's a diesel, i used to have all kinds of trouble with my 25xp until one lazy day i decided to read the manual - dumb me for not reading it from day one. it clearly said 60 seconds of glow plug - and i haven't had a problem since.

Bad Obsession · Jun 12, 2012

I agree with checking the electrical connection.

If it is a MKiii, It is diesel and, unless changed out for another engine, a Universal M25XP.

Have you tried starting the boat at the solenoid? If it starts up there well, then you may have an issue with the start button.

The engine ground can be a problem. Sand it and re-connect it.

One other thing that can cause you issues is the engine shut off not being put in all of the way.

Did you have enough water in the batteries? You should also check for dead cells (you could have a bad battery).

FastOlson · Jun 13, 2012

Gowing and Starting

Hal B said:
Thanks for the advise !! I will check all of the above things this saturday,.

I do have a Diesel, its a M25XP. I usually had to hold glow plugs for about 10 to 15 seconds. I will try holding them longer as well.

Thanks again.

We have an '88 M25XP. Glow plugs take about 15 sec. in spring temps, and about 30 sec. in mid winter when ambient temp is between 25 and 30.
As others have said, check all the electrical connections: plus side AND minus side, to and from the battery....
Also, if you have over 1000 hours on your engine, take off the starter and have it rebuilt. (Top bolt will take a wobbler, and maybe a short extension, and some cursing. The other, bottom bolt is easier. All this depends on access to that side of your engine, of course.

You will probably find that, even though it works now, it will work noticeably better after the rebuild.
That was our experience anyhow. Cost was well under $150. -- might be more now with some inflation.

Good luck.

Stu Jackson · Jun 13, 2012

Don't worry about a rebuild if your engine works after you start it. Man, I just hate it when doomsayers come up with this stuff. Maybe necessary, like this: http://www.c34.org/wiki/index.php?title=Rebuilding_the_M25-XP

But, most likely not.

What you really need to know is here, Critical Upgrades:

1. Engine ground
2. Wiring harness
3. Starter fuse hidden under alternator

http://c34.org/bbs/index.php/topic,5078.0.html

You could learn a lot from this, too: http://www.c34.org/wiki/index.php?title=Diesel_Engine

Wander around our website, we have a TON of M25XP information.

Bob4203 · Jun 14, 2012

Remember......................once the engine has been warmed you DO NOT need to use the glow plug again unless the engine is cold. Just the starter button will do the trick.

Bob
"88 Mark II (M-18 Universal)

mortyd · Jun 14, 2012

bob, the manual is addressing a cold start, but maybe it's wrong.

Bob S · Jun 15, 2012

Hal,
I had the same issues when I bought my boat in 2007. The PO had just put in 2 new group 24's from West Marine. I had to cross my fingers and use "both" batteries and she'd just turn over. Stu helped me that year with a complete electrical upgrade like Mainesail has posted many times. The first thing I'd do is replace the stock 4 awg wire to at least 2 awg. Some increase to 2/0. Do it with all the wiring pos. & ground sides. It made a huge difference in cranking speed. It's not a cheap endeavor but one of the best ones I did. At least I don't worry any more that she won't start up Sunday when I have to head home.

mortyd · Jun 15, 2012

guys, isn't it s.o.p. to use both batteries for starting? is on my boat.

Maine Sail · Jun 15, 2012

mortyd said:
guys, isn't it s.o.p. to use both batteries for starting? is on my boat.

No. If you "need" two batteries to start one of these motors it is only masking a larger issue. That larger issue should be addressed. These engines will literally start on a PWC or motorcycle battery IF properly wired and IF the batteries are healthy...

mortyd · Jun 15, 2012

i didn't say i needed both batteries, just i think it makes sense since once i start i will be motoring and charging. so, why the big NO? just like having a little more drip from my stuffing box rather than a little less, can you tell me what harm using both batteries causes?

Maine Sail · Jun 15, 2012

mortyd said:
i didn't say i needed both batteries, just i think it makes sense since once i start i will be motoring and charging. so, why the big NO? just like having a little more drip from my stuffing box rather than a little less, can you tell me what harm using both batteries causes?

It won't cause any harm unless your house bank is dead and larger than the start battery. In that scenario there is potential to not have enough CA to start the motor. In most cases your starter will like having more CA. If your alt is fed that way then nothing wrong with it but there should not be a "need", cranking wise, to do so, hence the "NO"... I read it in the context of the thread, which is on "weak starting", and I took it as a general need to start on BOTH. As I said if you "need" to start on BOTH you have a problem that needs to be addressed.

You can start on BOTH but you should not need to to get the motor running..

Stu Jackson · Jun 15, 2012

Starting on BOTH

mortyd, you're a regular on this board. Don't know if you read all the topics, but we have been discussing boat wiring for as long as I've been around here. Both Maine Sail and I are proponents of two major electrical improvements:

1. Removing the alternator output (AO) from the C post of the 1-2-B switch TO the house bank

2. Installing an echo charger (or like automatic method) to charge the reserve bank

This makes the 1-2-B switch a "use" not a "charging" switch. It completely avoids the problem of someone turning the switch when the engine is running and blowing alternator diodes.

Starting the engine on BOTH is only necessary if the AO remains on the C post of the 1-2-B switch and you want to charge both banks.

In most cases the reserve bank is always full. Use the house bank for everything.

Here's the information I shared that Bob discussed when we worked on his system:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

mortyd · Jun 15, 2012

it it ain't broke.........

Stu Jackson · Jun 15, 2012

mortyd said:
it it ain't broke.........

That's one approach.

The one we choose to take is to advise people of their options and explain why & how things work so they can make their own decisions. Too many people have no clue as to how their boats are wired and how the simple and very useful 1-2-B switch works. We hope skippers can learn from our experiences.

Maine Sail · Jun 15, 2012

mortyd said:
it it ain't broke.........

If all that switching works for you that's great, keep it. But three alts in the last for weeks all toasted by owners misusing a battery switch is but one reason why Blue Sea, Xantrex and others are selling soooo many charge management devices.