Monsoon 340 doesnt start

[justgary]

Sure, you could make sure it will turn by hand, but at this point it sounds like a poor battery if you really did clean all of the connections.  Did you have the stereo running while you were swimming, or was the battery just resting?

I would try charging the battery, or maybe swap it with your car/truck to see if the problem moves with it.

[KDCr7]

I did go through all the connections with sandpaper a couple weeks ago when we had the original starter problem.  I'm leaning towards battery although I had a borrowed deep cycle in all week while everything was working.  It was a little undersized (585 mca if I recall). 

Brought my battery home, will get it load tested and go from there.

 

 

[KDCr7]

So battery tested good at Interstate. Going to replace the the ICM (picked one up a while ago for idle issues).

How long will the starter spin if holding the key turned over.  I'm wondering if the ignition could be the issue.

 

 

[formulaben]

6 minutes ago, KDCr7 said:

How long will the starter spin if holding the key turned over.  I'm wondering if the ignition could be the issue.

Well, for quite a while...longer than you should allow if she doesn't fire right away, as the starter gets very hot and it only rated for intermittent use (I'd guess 30 seconds until cool down, but just a guess.)  I want to be clear here: please tell us is the engine turning over (rotating) when you try to start, or are you only getting a click from the solenoid (no rotation)? 

You're now talking about ignition and that makes me wonder if we are trying to help you with the wrong problem.

 

On 7/11/2021 at 2:31 PM, KDCr7 said:

We'll boat ran for over a week with new starter, then yesterday we were stranded out on the lake.  Drove out for a swim, went to start back up and no start.

Been going through the no start trouble shooting guide and closest I got was a sputter. Thought it was hydrolock because I am getting some rotation when starter cranks, so it is engaging.  Best way to describe it is only getting half a crank.

 

On 7/11/2021 at 4:03 PM, KDCr7 said:

...tried turning it over with the key while the plugs were out. It was still only giving me a partial crank.

So it was the same with the plugs out, or no?  With no plugs installed, she should rotate fast and easy with no compression to slow it down.

I really don't know the difference between "getting half a crank" or "partial crank" (but I do think I know what a sputter is), so would you please you confirm exactly what the engine is doing?  Is it turning over?  Does it rotate a bit then stop?  Does it rotate slowly but continues to crank the engine?  Does it rotate and just not start?  Please be more specific on what is happening here. 

The more I go back and re-read your posts, the more I think you may have vapor lock.  You said you went for a swim and then went to start and no start...you didn't specify exactly how it didn't start, but my hunch is vapor lock.  I fought vapor lock for 2 years and fixed it for good with the aux fuel pump...fairly simple to do.  Next time it doesn't start, take some ice in a rag and put it on the fuel pump for a bit.  If afterwards the engine starts up normally, then you've confirmed vapor lock is the culprit.

Anyway, if the engine is not turning over when using the key switch, then I would jump the starter directly, and if it turns over as it normally would, then your problem is an electrical one between the ignition key switch and the starter: those items include the key switch, wiring, starter relay, and solenoid. 

If the engine is turning over normally with the key (cranking) but not starting or firing, then you have an ignition or fuel problem, not a starter problem.

[KDCr7]

14 minutes ago, formulaben said:

So it was the same with the plugs out, or no?

 

15 minutes ago, formulaben said:

Does it rotate a bit then stop?

Yes it rotates a bit then stops. 

Exactly the same with plugs out. Rotates a bit then stops.

19 minutes ago, formulaben said:

you didn't specify exactly how it didn't start, but my hunch is vapor lock

Before the no start problem, we went for a ten minute cruise around the lake (25 mph). Weather was quite hot for our area 30 celcius (about 86 F i think). Stopped in calm spot to swim for half an hour or so, no stereo or shower etc running. When I went to start her up just got the short rotation.

My neighbors brought out a battery I had charged up (same one I got tested today, which passed) and same symptoms.

Regarding vapor lock (never dealt with it before), would it cure it self over night with lower temp?

 

[hawaiianstyln]

I know that it wasn't your electrical/connections anywhere after reading, but this stuff is down right amazing!!  It helped me survive two Malibu's in the salty Hawaiian Islands.  If you can only imagine keeping up with all the electrical connections especially in a salt environment.  Heck I STILL use it today even tho my Malibu I have now is in fresh water and never touched salt.  I pretty much used it on EVERY connection or electrical contact.  Brought the last Malibu to Phoenix and did a quick wipe down and degreaser and the Malibu dealer said the boat looked in better shape than their fresh water boats (well I also have serious OCD).  

Edited July 13, 2021 by hawaiianstyln

[formulaben]

4 minutes ago, KDCr7 said:

Regarding vapor lock (never dealt with it before), would it cure it self over night with lower temp?

Yes.  As the engine block cools down, the fuel will no longer vaporize and will start normally. 

I suppose you could have 2 problems here.  I would do as I earlier described, jumping the starter directly and see if there is a change.  Additionally, the next time it doesn't start, take some ice in a rag and put it on the fuel pump for a bit.  If afterwards the engine starts up normally, then you've confirmed vapor lock is happening.

[KDCr7]

@formulaben I'm heading back to the cabin the in the next few days and will try jumping the starter first.  Will definitely keep some extra ice handy, especially if this heat wave keeps up. 

Also thanks for keeping me on track. I'm normally quite methodical but it seems when the boat goes down I get scatter brained. Just need to stay calm until I can get back out to the lake 😄

[KDCr7]

@hawaiianstyln Right on.  I just found T9 locally. Going to pick it tomorrow. 👍

[KDCr7]

Just wanted to update.  Got her running again! I could fire it up jumping the starting but not with key. Replaced the ignition switch with a new one and she started right up. Not sure how the old one partially engaged but the new one works. 

Thanks for all the troubleshooting help. Really did narrow down where the problem could be. 👍