Left yamaha flushing connectors disconnected underway

CDory23

I was out in the boat today 22 Classic with 2003 twin carbed yami 40's. Everything was running great for probably around 45 minutes on the water. While underway at around 4700rpms my starboard motor started bogging down, sounding rough and wouldn't stay above 33rpm under full throttle. I stopped the boat to inspect and the motor is idling very hard and shaking. I look down at the outboards and realize I have left the flushing connectors off. Water was still coming from telltale but obviously not for optimum cooling.

The Port motor is still fine, but the rest of the day the starboard motor shook at an idle, sounded rough and wouldn't get above roughly 33rpm. So now I"m wondering did I overheat the engine? Damage rings/cylinder? Well I would think the overheat alarm would have still warned me about it before any damage would occur. Any ideas?

My plan tomorrow morning is to check compression. Also I need to figure out a way to test my overheat alarm and sensor to make sure that My optimistic side is wondering if a spark plug could have fouled.

hardee · Posted: Wed Feb 17, 2016 2:36 am Post subject:

I have not had this happen ...yet. Hopefully your optimistic side is right. Hopefully we will hear from Marc or Larry or Les, (Mechanic types here) or someone else who can help.

I'm holding my breath with you. Need to know in case Embarassed

Harvey
SleepyC Moon

CDory23 · Posted: Wed Feb 17, 2016 4:02 pm Post subject:

Here are the results of the Compression test, I did both motors for good measure.

Port (motor without isssues) #1-145. #2-150. #3-150

Starboard (motor with issues) #1- 150. #2-150. #3-150

The Yamaha factory manual says psi should not be less than 175. I'm going to assume this is just a characteristic with my compression tester.

Spark plugs on Port motor were clean, Spark plugs on Starboard motor were darker, looked a little oily, not horrible.

Put all new plugs in and ran on earmuffs- same symptoms, very shaky, and even dies every few minutes.

I"m very aware that these motors have carb issues and I've had carbs replaced on both and since then per mechanic always run the motors on muffs at least every two weeks if boat is not in water to get some gas run through them.

With that being said, is it possible its another carb issue and I just quincidentally left the flush connector disconnected at the same time this happened? It makes me wonder everything running great and then suddenly to have the symptoms I described in my first post.

Thanks.

Marco Flamingo · Posted: Wed Feb 17, 2016 4:14 pm Post subject:

I just did the same thing yesterday on my Yamaha 50. After a few hours of sea trials, I put it back on the trailer and when I went to flush it I noticed that the hose connector hadn't been screwed back on from the last time I flushed it. The connector is on the same side as the pee stream, and I check that every time I start the engine, but I hadn't noticed anything was amiss. I probably started it 5 times and it always seemed like a strong stream. I ran it several times at WOT for a minute or more.

My guess would be that the cooling water needs to circulate and come out somewhere. It might not matter where. . . . I hope.

Mark

BrentB · Posted: Wed Feb 17, 2016 4:41 pm Post subject:

We need more info.

Do you have separate fuel/water filters and gas tanks for each motor? Added new gas recently? E0 or E10? Any water in fuel/water bowls?

CDory23 · Posted: Wed Feb 17, 2016 5:00 pm Post subject:

Both engines get the same fuel from 1 water filter/water seperator. I will check the carb bowls.

My next step is to run a heavy Seafoam mixture through that engine through an auxillary tank, and then replace the inline fuel filter in the motor itself.

CDory23 · Posted: Wed Feb 17, 2016 5:05 pm Post subject:

i just use 87 at the normal gas station but never use fuel more than 3 months old.

BrentB · Posted: Wed Feb 17, 2016 5:06 pm Post subject:

thanks! good luck

CDory23 · Posted: Wed Feb 17, 2016 5:42 pm Post subject:

drained the bowls, seemed to be fuel, although difficult to tell. Another piece of information is the last couple trips I have had spray from transducer hitting the starboard motor (motor with issues). I didn't think any would get into the engine since the cowling is a tight fit but I notice corrosion on the #3 carb. I sprayed Corrosion X on it to help and I would assume this is mostly surface and not effecting the interior components on carb.

I"m currently making a spray shield so this no longer happens.

PaulNBriannaLynn · Posted: Wed Feb 17, 2016 6:28 pm Post subject:

A good friend and Honda/Yamaha outboard mechanic told me once that a large portion of her business wrenching on Yamaha outboards was due to people using their flush port with the engine running. This gets water in all sorts of places it shouldn't be, or so I'm told. Do you have water in your engine oil?

I'm a Honda guy and I don't have a flush port on my 03' motors, but from the symptoms it sounds exactly like my motors when I've had crap stuck in my high speed jets. I think your seafoam treatment is right on and would be my next step to see if you get improvement.

CDory23 · Posted: Wed Feb 17, 2016 8:32 pm Post subject:

I may be missing something, but I don't see how the flush port would get water in places it shouldn't be normally. Also, the problem wasn't from running the engines while using the flushing connection with a hose, but actually leaving it disconnected while running the boat in the water. To me, all I think this would do is lessen the flow through the jacket and shouldn't cause any damage.

I think you are right on with debris in the carbs. I'm beginning to lean towards this being quincidence and just being carb issues again.

BrentB · Posted: Wed Feb 17, 2016 8:44 pm Post subject:

I think you are spot on and sometimes Sea-foam which is mostly naphtha (ex. lighter fluid) requires overnight soaking of the carbs and spraying into the throat

CDory23 · Posted: Wed Feb 17, 2016 8:53 pm Post subject:

Yes, If Seafoam doesn't do the trick, I told myself after last time I spend $$ on carb issues I wouldn't do it again, and I"m sticking to this.

This may be a new thread but I'm currently exploring options for twin 50's. I feel my Yami 40s I owned were under powered. Unfortunately the mechanic I've been going to and know and trust is only servicing and dealing with Mercurys. I'm not opposed to them, but in the research phase. I've gotten a few estimates already and even with all the new rigging of the mercs I'd be paying the same to buy new Yamis and keep the Yami rigging I have.

BrentB · Posted: Wed Feb 17, 2016 9:16 pm Post subject:

Have you replaced the fuel hoses recently? They can deteriorate from the inside and can be overlooked

CDory23 · Posted: Wed Feb 17, 2016 9:18 pm Post subject:

I have not. I will check on that as well tomorrow. Easy replacement.