HELP! Dieseling at shutoff, then won't crank...

[gyoungberg]

Hello everyone,

I was out on the Snake River in Idaho yesterday teaching some Boy Scouts to waterski. All was going well until I shut the boat off and it began dieseling fairly badly. It had never done this before. It finally died and I tried to start it back up again. It wouldn't do anything but a hard Click in the starter. The battery still would raise & lower the outdrive easily, the horn was strong, etc. I think oil pressure was good, but I hadn't paid much attention to it the last several minutes. The engine temp was also ok. I haven't had starting problems at all this season. Any ideas where to start?

I've got a '95 Reinell 18.5' with a 4.3L and Alpha I outdrive.

I really appreciate folks like yourselves who give of your time to help us poor lost DIY'ers!

=========================================================
I originally posted this in the wrong forum (oops), so I'm reposting it here. I did get this response, which I greatly appreciate from Bond-O:

Ayuh,....... You're in the Wrong forum,....
But,........
I'd say that your motor is now Hydro-Locked.....
Pull the Sparkplugs,+ get the Water out of the cylinders......

=========================================================
I will get out first thing in the morning and start looking into this deeper, but I don't understand how this could have happened. Does the dieseling play into it somehow? Hopefully I haven't hurt things by not already having taken care of this..:redface:

 

[billbayliner]

Re: HELP! Dieseling at shutoff, then won't crank...

I am thinking because of the dieseling the enginemay have injested water into a cylinder and you are hydro - locked as water will not compress. Pull the plugs to see if there is any water in the cylinders.


Bill

 

[Haut Medoc]

Re: HELP! Dieseling at shutoff, then won't crank...

I am thinking because of the dieseling the enginemay have injested water into a cylinder and you are hydro - locked as water will not compress. Pull the plugs to see if there is any water in the cylinders.


Bill

There is your answer.......^^^^^^......
You have ingested water from the engine spinning backwards....
Get those plugs out, spin the motor, & get it up & running again A.S.A.P.........
Luckily, you are in fresh water & if you don't wait, you will save your engine........
DO NOT DELAY!
You should change your oil & at some point, check to see if you still have exhaust shutters....

 

[gyoungberg]

Re: HELP! Dieseling at shutoff, then won't crank...

Thanks to everybody for the advice! I'll play hookey from work this morning to get after this! If I decide I'm in over my head, I'll take it to the shop.

Any ideas what caused the dieseling? It's never happened before. I'd hate to get all the water out, just to have it suck a bunch more in next time out!

Thanks again.

 

[tommays]

Re: HELP! Dieseling at shutoff, then won't crank...

High motor temps from hard running are a big cause of dieseling


The fact that your skiing would point towards a lot of hard running without being able to allow the motor to idle for 2 or 3 minutes to COOL down before stoping it




Tommays

 

[mcbridek]

Re: HELP! Dieseling at shutoff, then won't crank...

I did the same thing on my 97 Four Winns - turned off the key when the engine was running above normal idle speed, engine knocked when shutting down and sucked water into the engine. Once you clear the water out of the cylinders, you will also need to change the engine oil, there will be water in it.

 

[gyoungberg]

Re: HELP! Dieseling at shutoff, then won't crank...

Well, I wish I had been runnning hard. Since I was teaching a few Boy Scouts to ski, it was mostly... "Hit It!" then turn back around, wait for them to put their skiis back on, get the rope to them and try it again!

When I shut it off, I was coasting up to another boat to talk with them for a few minutes. I had it in neutral and had just about coasted to a stop when I shut it off, so it still doesn't make any sense.

Based on everybody's advice about the urgency of the situation, I called my boat dealer and he said he would get right on it. So I took it over to him. I'd hate to find I ruined my motor because I was too cheap to have someone look at it that knew what they were doing!

Thanks so much to everybody for your thoughtful advice. This is a wonderful website because of wonderful people!

 

[Haut Medoc]

Re: HELP! Dieseling at shutoff, then won't crank...

Well, I wish I had been runnning hard. Since I was teaching a few Boy Scouts to ski, it was mostly... "Hit It!" then turn back around, wait for them to put their skiis back on, get the rope to them and try it again!

When I shut it off, I was coasting up to another boat to talk with them for a few minutes. I had it in neutral and had just about coasted to a stop when I shut it off, so it still doesn't make any sense.

Based on everybody's advice about the urgency of the situation, I called my boat dealer and he said he would get right on it. So I took it over to him. I'd hate to find I ruined my motor because I was too cheap to have someone look at it that knew what they were doing!

Thanks so much to everybody for your thoughtful advice. This is a wonderful website because of wonderful people!

Yes, it does.....
That following wave went right up the tailpipe....

 

[180shabah]

Re: HELP! Dieseling at shutoff, then won't crank...

When the engine diesels it doesn't matter if the boat is moving or not. Your exhaust is full of water, and if the engine spins backwards, it will suck that water out of the exhaust into the engine.

 

[gyoungberg]

Re: HELP! Dieseling at shutoff, then won't crank...

Well, I got the boat back. It was hydrolocked and had water in the combustion chambers and the crankcase. They had to change the oil about 5 times before it would stay clean. I also had them change out the gimbal bearing which was starting to make a lot of noise since it was already in the shop. Took it out on the water yesterday and it's running great! Total repair cost about $240 for the hydrolock/oil changes and $350 for the gimbal bearing.

On an embarrasing note, the dealer said that the very dirty spark arrestor probably was the primary reason for the dieseling. I remember looking at it last spring and thinking, "I probably ought to clean that one of these days." Repairs caused by poor maintenance -- my bad!

I really appreciate everyone's advise. Mostly in that it got me to take care of the problem immediately instead of waiting for a convenient time and finding out it was too late.

Now out for another day of boating

 

[euphomus]

I know this is an old thread, but I had almost the exact same conditions happen - coincidentally on another four winns. Thankfully, I keep a decent set of tools onboard. Removed the plugs. Half were a little wet but the #8 was full with water. With the plugs out, i turned over the engine briefly to clear all the cylinders of as much water as possible, returned the plugs, gave her A LOT of gas, and was able to recover the engine to get me back home.

Thanks for the old advice above. Glad I could get it on my smart phone!

I'll be changing the oil and filter today, and cleaning the spark arrestor as well!

 

[Fun Times]

I know this is an old thread!

Hi there euphomus, sorry to hear your boat experienced something similar as what had happen in this old thread/topic. We are also very happy to know that this past information was able to help guide you at getting your boat running once again.

Please know that it is the wishes of our hosts here at iboats that old threads like this one are preferred to be used as a reference only and there really isn't a need to thank it years later as most are aware that old archives help many boat owners in their search for answers.

Please see the "Help Tip": near the top of the forum page for further details about bringing up past threads. Thank you iboats mod team