Sudden power loss with prop. or something else??

P

primative

New member
I have a 99 , 22'CD cruiser. I bought it as a new demo., in 99 at Sportcraft Marina in Portland. It came with a new 1997 Honda 90.The prop.it came with is a mercury 13 1/4 diam. x 17pitch.They said this size was best and the next size being the 13 1/2 x 15 (Honda) would be too much of a work prop.( low speed with high rpm). Over the next few years I used the boat primarily for day/weekend trips, and the perfomance seemed acceptable, but was less so when heavily loaded for extended type trip.Meaning boat would have difficulty planing and could not develop adequate rpms.

So I called 3 to 4 c-dory dealers from WA. to Florida, and they all said, OH, you should be using the 13 !/2 x 15 that the motor standardly comes with, and thats what we all have best results with.I was told I would have rpms nearer to 6ooo at wide open, as compared to the low/mid 5000's I was used to with the original.

In July, 04, I put on the 13 1/2 x 15, and man does it feel responsive(getting up on plane easier, and better control at the low end speeds which I feel the boat is best suited forl). Unfortunately, when I run the boat at higher rpms( last incidince, above 5200-5400) for 5-10 minutes it suddenly loses power with simultaneous alarm beep for a second or two. I noticed brief flash of the red light last time, but not neccessarily in previous episodes. I originally thought it may be a fuel starve problem, but now I wonder if it is a cavitation problem at the higher rpms, though I do not sense any slipping of the prop.

This may be a seperate problem/s, but I've added some recent repair history that may be useful.

Sport Craft changed my water pump Sept. 03 , because of a history of abrupt power loss episodes developing in a two week camping trip, using boat every day, progressing to alarm with red light coming on.

In june 04 while towing skiers, developed loss of power. The boat would power back up again normally,and lose power again, until idling a bit. Initially it didn't cut out before about 4000 rpm, then progressed to cutting out around 28oo, (the alarm-red light never came on during this episode) and we just didn't try planing any more to get back to the dock.
Took it in to Sport Craft to check it out. They said" fuel good, thermostat operation ok, changed plugs just because, and river tested twice without any problem, and don't have any ideas/solutions to try further", if its not showing problem.

Fellow dorymen if there are some obvious answers I sure would appreciate it! If not, I would like your recommendation for a mechanic on this problem. Sport Craft has treated me well, but I may need a second opinion. No one can be expected to have a solution all the time.

Thanks,
Tom and Rene, the Primative
 
Tom and Rene,

Overloading the motor with a prop pitched too high or with a heavy load ( or skiers)can cause an overheat/slowdown from high rpms.

A fuel system restriction can cause a similar thing. The motor gradually 'starves' for fuel until the carb bowls run low or dry. The motor abruptly slows down until the fuel pump catches up with the carbs.

What does your owners manual say about the alarms? What does the red light or warning horn mean?

Your motor may have an automatic slowdown protection circuit to protect the powerhead from overheat/low oil pressure. Your owners manual should tell all.
 
Larry S. and Larry of the Nancy H thanks for responses. I took the hint on checking the manual for light/buzzer indications. I think I'll need to take the boat out again and try to reproduce the shut down and get more certain what light I'm seeing or not, with buzzer or not. Actually it states the buzzer would always sound in either case of low oil press. or overheat. I'm thinking its best to to get the problem to repeat before trying to go any further. We're getting some arctic air and predictions of snow this week, hope I can get out. I have a particularly steep set of roads near my home, so we will see.

tom
 
Took her out 1-6-05.
I produced the problem by running at or near w.o.t., 6000~5500 rpm, and doing zig-zag pattern path. Motor abruptly slows down to idle with simultaneous alarm and red light, indicating overheating, for a second or two. I could then resume normal operation. Oil pressure light never went off, indicating no loss of oil press..

So it would seem the S-turns produce cavitation related overheating, due to changing angles of the prop as I banked side to side, Right?

The anti-ventilation plate is approx. 1" below my hull.

Has anyone else experienced this? What to do?
-Tom
 
Tom, very strange. What does the telltale do during these times? That's the cooling water that comes out of the underside starboard side of the engine. If it's continuous, then I'd suspect a sensor problem. If not, it may be a water pump problem (impeller or the like), although that should manifest itself at other times too.

You said the thermostat was OK, that also should show up at other times if it's sticking. Sounds lilke a sensor to me. But then what do I know....I'm the one that takes stuff apart to fix it, puts it back together (sometimes) and am surprised when it works again. I even set the family record player on fire when I was a kid when I hooked my crystal set to the phono pickup to try to amplify my signal. Whooooooeeeeeee :smilep

Charlie
 
Tom how's it going?

Overheating is not something that comes and goes in a few seconds. Start with getting a tech manual and id the location of the sensor/sensors check the connection and wire path frist. Maybe a bad sensor or wire rubbed through.
Give me a call be happy to assist.

stevej
 
Charlie,

thanks for the the responses. You had me there for a moment with the term,"telltale", and fortunately you explained it. I've been using the technical term "peewater" for so long I didn't know what you were talking about.

It pees good, I mean well, that is, the telltale is fine, I think all the time. From what you've said, and Steve J's response, I'll be checking the sensor.

Charlie I'm glad you're the kind of guy who takes stuff apart, because now with good telltale I'm not thinking prostate gland.

Steve, thanks for your input about the technical manual... good idea. It's a must for me. I'm relieved to have some leads to follow here.

Tom
 
Hmmm. Got me to thinking, maybe it's my sensor, not my pump. Tried it last night about 3AM and sure enough, when I put my hand in a bowl of warm water, the pump worked fine...

:oops: :lol: :lol:

Good luck, let us know what the outcome is...

Charlie
 
Tom...... Having had a similar problem in both cars, trucks, inboard boats and outboards.... some sort of fuel restriction situation should be considered, be it fuel filter or kink in the supply hose somewhere... I would rule that type of thing out before taking too much apart. I did have one, two engine jet boat that had either a bad sensor or a short in the sensor since which ever engine we installed that sensor on - that was the one that beeped and lit up.

btw...you guys are alot of fun to read! John
 
Dr.John, thanks for reply. Too busy to check sensor yet. Going to Seattle Boat Show and mostly hang with dory people for fun and land adventure.

Now for a surprise. My wife Rene and I are both from McPherson Ks.

Gotta stay on schedule and will get back to you.

Tom
 
Tom , Wow, that is close! I bought fish to stock a pond on my old house years ago from Mc Pherson. I work in Wichita, but live on a farm just East of Harper , KS which is about as far SW of Wichita as Mc Pherson is North of Wichita. I wish I could be at the Seattle Boat show - maybe another year. Although I started the note discussing fuel restriction, it does sound to me exactly like that defective sensor I had on that jet boat. It would go off right after a load, turn, etc.. Good luck on the boat problem. John
 
Well, I don't know about the "overheat" alarm, but I don't think it would overheat and cool off just doing S-turns.

As far as the intermittent motor shut-down goes, it sure sounds like a fuel issue. Maybe water in the tank? I had a similar problem last fall. I would be cruising along and the motor would just kick back to idle all of a sudden. Then it would roar back to life for no aparrant reason. After much hair pulling, I finally traced it to a leaking fuel cap. Turns out there was about a quart... yes, a quart.... of water in the gas tank. :shock:
 
I did not mean that the engine actually overheated.... on the contrary... the alarm kept going off, but the engine never actually overheated.

Water in the fuel, or some junk in the fuel filter ... likely if slower onset...

anxious now to see what the problem really turns out to be! john
 
My plan is to take the boat out again with a friend this Sat, and check more specifics.

I was told by my boat dealer (after he asked his mechanic) to disconnect the sensor plug and see if the red light and alarm still goes off. He said he had never seen a heat sensor problem, and his experience of thermostats is that they are more apt to stick in open position than closed. He wondered about the water pump, but I reminded him they changed it in 2003. He was thinking I might be over revving (activating the rev limiter) when I made the sharp turns with my last test run, but I told him it had done the same thing the time before that, at 5400-5500rpm going in a straight path, though there were three people in the boat and gear providing a heavier load. If not over revving he was guessing maybe Electrical module component as next possibility.

I looked at the heat sensor wire and it's fine.

My friend will be bringing a device to get actual water temp when we get shut down-overheat light-alarm. He also mentioned being curious how the sensor relays or receives charge and this might be useful too.

Navicula thanks for your response. I don't know much about motors or mechanics in general but these are my thoughts on it not being a fuel blockage/water problem.
If this was water fuel blockage, the red light that indicates over heating would not be coming on, and my" Racor " view type fuel/water seperator would show water, if it was water. At least when I had some water in the past it showed well.

I'm looking forward to Sat., less talking by me, and more of something else.

tom
 
Went out with two friends on board and it consistently shut down about 5300-5500 rpm. Took temp. near the thermosensor at top cylinder with infrared type point and read gun with temperatures from 202 to 214, but mostly 202 at top and 165 to 175 at bottom. Forgot to disconnect the thermosensor to see if red light/alarm would occur anyway.

Called two differerent mechanics, at honda dealers. One says I'm definately overheating. The other says nah, the top cyclinder runs hotter than the bottom and we ( dealer and mechanic) don't think it's really overheating. When pressed if internal tempuratures are known by them, they do not know.
1-26-05
So I took her out for another test, with the idea of disconnecting the thermosensor for a short period to see if red light/alarmbuzzer would go off. It turns out that I could not create a shut down with the thermosensor connected or disconnected. I ran the motor harder than I did in the 1st trial, but it did'nt matter, no dysfunction occurred.
The tachometer during most of this trial was improper, with readings at W.O.T of 6700 to 6900-7000. When reducing throttle by ear to approx. 3/4 full, the tach. read 6100-6200.When the motor was checked out back in 6-04 at the dealer they made mention in the work order that there was tach. malfunc., but no overheat light/alarm produced. This is the 1st time I had witnessed it myself since their mention of it 6-05. When asking about this recent episode they think it is most likely unrelated to the "shut down to idle episodes".

2-2-05
Bought a new thermosensor at dealership. I installed it and tryed another river test while there. If problem occurred they suggested thier mechanic go out and check for himself ( I was told by feel/experience) if the motor was overheating. It never malfunctioned, and I ran in harder (closer to W.O.T.) than I did in the previous two trials. I shot temperatures again, I guess for the practice of science. The top cylinder 202 to 217 degrees from 4200 to5600 rpm.The bottom cylinder 160 to 178 degrees. Oh ya, the tach. worked fine during this trial.

The dealer said until the problem presents itself more consistently there is nothing they think there is to do at this point.

Want to go out in ocean with me? I did'nt think so. Me neither until problem solved.

tom
 
Tom,

Has your thermostat been checked?? Over 200 degrees seems way too hot for an outboard.

You may want to call Les at E Q Marine.

Or, try to talk to a Honda tech rep. Get a dealer to make an appointment or a least a phone conference.
 
Avoided dealing with this, decided to do some fun outfitting. Installed a windless Sprint 600 and Delta anchor with Simpson Lawrence bow roller. Also a motor bracket to keep the 8-horse from dragging and an automatic bilge switch for the rear bilge.

As with all overindulgence, one must come back to reality... the unpredictable but recurring motor overheat-shutdown problem.

I spoke with Less Lampman as Larry suggested. He recommended I inspect the water pump impeller and change it even if it looks OK, and it looked fine. I replaced it.

I took a test run yesterday and within the first mile from the launch it had the sudden loss of power to idle speed with simultaneous red light and alarm buzzer for about two seconds. As soon as the throttle was brought to neutral I am able to take off again to planing speed. The shutdown problem recurred four or five more times over the next few miles, traveling at 4200 rpms. It seemed as if when I kept it at 3900 or below, the problem did not occur.

We checked the windlass several times and it works great. After lunch we hung out at anchor for a couple of hours before returning. On our way back there were no malfunctions, regardless of cruising between 4200 and 5600 rpms.

This problem is running on into many months. I plan next to replace the thermostat even though it opened in a cup of hot water when I checked it earlier. A Honda Service Manager from a dealer on the coast told me today that even if it opens we don't know what temperature it's opening at, or how well. He said my thermostat should open at 155 to 160 degrees. Based on the temperature readings I've been getting at the top cylinder near the thermosensor, 190 - 215 degrees (more often 202 degrees), he thinks I'm running too hot.

I want to say here that at times I can't reproduce the problem by making the motor work harder, i.e. higher rpm's with heaver loads and registering at the higher temperatures.
When the problem is occurring I can't even get it up to the higher rpms because it's already cutting out.

Stay tuned... and as always, your input is welcome.
- Tom
 
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