Occasional stalling when shifting

[180Diablo]

Just wondering how I would be able to tell if this is a possible loose/wearing out shifter cable or a normal condition and I need to just deal with it.

Boat im referring to is the one in my signature. 93 mariah, alpha I, Gen 2, 3.0L.

After letting my boat idle at the dock for a good couple minutes, lets say around 5 minutes+ or at least till it gets up to temperature, when I go to back it out of the slip, the odd time it will stall on me. Normally it stalls on me only one time and the second time shifting I have no problems. Once I have switched into reverse and then switch to forward and head out for a few hours its seems fine. It hasn't stalled on me when coming into dock, however it sometimes seemed like it would stall.

When I was last up there two weeks ago, I tried to watch and listen to the motor to see what rpms the motor would cut out at when attempting to shift to neutral then to reverse. From what I saw, this would happen when the rpms drop below 1000 to around the 700-800 range.

If I let it idle around 1000rpms and shift fairly quickly before the rpms really have a chance to drop off, there is some grinding that I hear, but it does go into reverse without it stalling. Yes, I know grinding equals bad and thud equals good and to shift it as quickly as you can without over-throttling and throwing your passengers into the stern.

Complete engine tune-up was done in May, gimbal last year, outdrive oil serviced. Besides a carb rebuild a few years ago (boat sat winterized in storage from 04 to 06) and whatever my marine mechanic has done I am unsure on any other work being performed on the boat.

So what I was wondering was, am I possibly fighting something that needs to be replaced / looked at OR is it something that is normal and it's just me that needs to work on his shifting skills to prevent stalls. Is there any in water checks that I can perform with the engine off to listen for or to see if its shifting properly?

Not mechanically inclined enough to remove the outdrive to do a check that way. Checking oil and looking for problems is about as far as I go.


thanks for any help/replies

 

[gogodiablo]

Re: Occasional stalling when shifting

I have the exact same boat, and a similar problem...

Engine would stall every time I put it into gear UNLESS I gave it lots of throttle and nearly threw out the passengers!
I thought I had a shift cable problem, but after breaking the shifter (long story) I had the cables removed from it, and tried it in my driveway, with my outdrive in large tub of water (for resistance on the prop).

After getting the engine started and set to idle, I manually moved the shifter cable ONLY to engage the drive. Did this several times in forward and rev. NO STALLING...

Satisfied the interrupter was not the problem, I tried the throttle cable and moved the RPMs to about 2000 for a bit (in neutral). When I dropped the throttle back it would not stay running, I had to goose the throttle to keep it from dying. It runs ok at WOT and sometimes at idle, but doesn't like it when the throttle is opened.
The plugs are new, and compression is good. I belive the ign. is eletronic so no points, haven't checked cap and rotor yet.

I'm thinking this is a carb problem.. Anyone have other ideas? Something I've missed? Does my trouble shooting sound ok so far???

 

[wcsparky05]

Re: Occasional stalling when shifting

what hp is your engine? mine just stalled for the first time ever, twice, and embarassing, last weekend. i have an '89 merc inline 4, 140 hp. same?

 

[Scaaty]

Re: Occasional stalling when shifting

I have the exact same boat, and a similar problem...

Engine would stall every time I put it into gear UNLESS I gave it lots of throttle and nearly threw out the passengers!
I thought I had a shift cable problem, but after breaking the shifter (long story) I had the cables removed from it, and tried it in my driveway, with my outdrive in large tub of water (for resistance on the prop).

After getting the engine started and set to idle, I manually moved the shifter cable ONLY to engage the drive. Did this several times in forward and rev. NO STALLING...

Satisfied the interrupter was not the problem, I tried the throttle cable and moved the RPMs to about 2000 for a bit (in neutral). When I dropped the throttle back it would not stay running, I had to goose the throttle to keep it from dying. It runs ok at WOT and sometimes at idle, but doesn't like it when the throttle is opened.
The plugs are new, and compression is good. I belive the ign. is eletronic so no points, haven't checked cap and rotor yet.

I'm thinking this is a carb problem.. Anyone have other ideas? Something I've missed? Does my trouble shooting sound ok so far???

tried it in my driveway, with my outdrive in large tub of water (for resistance on the prop).

Means little...water can be pushed easy...its when theres a boat in front of it that stuff comes into play...like jacking up your car so the drive wheels are off the ground...(''hmmm, works fine now??"

 

[gogodiablo]

Re: Occasional stalling when shifting

Agreed... But I have little choice... no shifter in boat, wont stay running, I don't have a slip to keep it at.. Best I could do under the circumstances...
Still, if the engine wont run in neutral, in the driveway, there IS a problem... I'm leaning towards the carb.
What do you think?

 

[180Diablo]

Re: Occasional stalling when shifting

Wow i was starting to think I wouldnt get any replies on this thread.. lol. I just gave up on it and I would see about chatting to some local marine mechanics on the weekend and see if they might be able to diagnose the lil (or big) problem I sometimes have.

Docking and going into locks would be my concern because of the very slow speed you have to go at to do both. If my boat is stalling, I wouldnt want to gas it up too much and risk damaging my boat or another persons boat.

 

[rmurray]

Re: Occasional stalling when shifting

This is the problem I'm having and the responses (similar)...

http://forums.iboats.com/showthread.php?t=210757

Hopefully this helps.

 

[180Diablo]

Re: Occasional stalling when shifting

Thanks Rmurray. Yep sounds basically what I mentioned before.

They should almost make the shift cables topic a sticky... lol. I think I will be making an appointment to see my friendly neighbourhood marine mechanic to have my cables looked at

 

[gogodiablo]

Re: Occasional stalling when shifting

180Diablo, Will you post or PM me when you hear back from you mech? I'm curious to what he has to say too.

 

[boltonranger]

Re: Occasional stalling when shifting

Ever since I bought my boat -'88 3.7 alpha one.
It has done what you describe...
In my case - I rebuilt the carb and thought I had it licked.
But on the water - I began to notice the same "slow death" idling that I had before;
And when I shifted it - often it would quit unless I gave it gas.

Finally one day I happened to adjust the idle when cold and the choke was working.
The engine went from missing and rocking to revving very smooth. I had found the sweet spot that had eluded me when adjusting the idle while warm. (merc 2bbl)

I left the idle mixture there- and when it was completely warm I dialed the rpms down to 750 - 800. I used a separate tach to get it right, the dash one isn't accurate enough.

My next time on the water was so different than I was ever used to.
It runs like a watch now. It never tries to stall when shifting. It doesn't need any throttle to keep it going. One crank and it fires now; hot or cold.
When cold it needs 1/3 throttle - when hot idle only; just touch the key.

It feels like a different boat now; but the reason I wrote this was because after the carb rebuild I was sure my shift/kill switch was the problem.

Your situation reminded me of mine so I posted.
Maybe it'll help -br

 

[180Diablo]

Re: Occasional stalling when shifting

180Diablo, Will you post or PM me when you hear back from you mech? I'm curious to what he has to say too.

Well to be honest I lied in my previous post. I never did end up going to see a mechanic about my cable / stalling issue/problem etc. I just drove the boat! LOL

I spent all last week at my cottage on holidays and almost every day was spent out driving the boat. The only times it wouldnt start or stalled was when I tried to cold start it in neutral w/o switching into "throttle lockout" mode and pumping the trottle 2 times to get it to start. It was a test my uncle had me do to see what happens.

Re-starting when warm in neutral proved to not be a problem and it would idle around 500-600rpm range. To me it seemed like it was shy of stalling on me.. BUT .. the boat idled and ran. I'am still learning the boat.

I know one thing that has improved, my shifting to forward/neutral and into reverse when needed. Experience is improving and my " grinding " is going away. So all in all. I think my cables might be fine for now afterall.

 

[boltonranger]

Re: Occasional stalling when shifting

What you describe sounds as though it has nothing to do with the cables; it sounds like your carburetor settings.

I believe 500-600 is too low of an idle setting.

You can get fooled if you:

1. rely on the dash tach.
2. try to set the idle in neutral.
3. try to set the idle out of the water (on muffs)

You must set it when Warm & In Gear & In the water.

Again that sound too low - mine is set somewhere in the high 700's
BUT on the dash take it reads 1050 or so...
You need a more accurate tach to tell you the story.

One of the Mariners can tell you your exact setting - trust me it will make a world of difference set up properly.
-br

 

[boltonranger]

Re: Occasional stalling when shifting

ibid-sorry.

 

[180Diablo]

Re: Occasional stalling when shifting

Well even if it does idle and run around 500rpm (dash tach) would it do any damage to the engine or components? I may have to get my marine mechanic to look at a slight hesitation when throttling onto plane as well. Happens normally when first getting onto plane then its fine rest of the day. I always assumed it was from not being run in a week or two.

Well the online Merc manuals (boatfix) should have the proper idle settings I would imagine as well. Which, is probably as you mentioned, around 700's.

I need to have someone properly teach (show) me the normal checks that are done on a daily/weekly/montly basis. Reading and looking at some pictures in a manual is one thing, but if you can't relate to where it is on the engine, is another.

I was considering taking the marine maintenance course offered by my local power squadron. Runs for 10 weeks and starts in January '08.