Honda BF 90 ( 2004 ) gives alarmtone when speeding

Hi there. I have following problem which i hope some of you may have a solution to.

My Honda 2004 BF 90 was out on the water for 6 hours, running smooth and perfect. After sailing to the port with almost full throttle for 1/2 hour, i took off the speed when arriving to the port. Then i wanted to give a little more speed, but a constant alarm tone from the control box starts, untill i take off speed and idle. Idle in gear there is no alarm tone, but as soon i give a little speed, the alarm begins. What can be the problem ? ( There is no oil problem )..

Thank you very much in advance for your input

Have a great day

BR / Danethor

What are your lights doing? Do you have a red overheat light and a green oil pressure light? Unless there is a malfunction in the warning circuits, it is either an overheat or an oil pressure problem.

Your lights should tell you the answer.

Mike

Hi Mike - the Honda oracle . Your time on us imbiciles are much appreaciated.

There is no signal from the lights. No red overheat light and green oil pressure light. So a malfunction in the warning circuits i can read from your reply ? How to handle that ?
Thanks in advance

Let me make sure that I understand......

I think you said that the green oil light was not on. If that is the case, then it is an oil related alarm.

Let me know if that is the case.

Mike

Sorry for not being clear. Green light is on, - and no red light on. So both lights "normal" = no indication of any error.

The alarm is turned on by a ground from the CDI unit. The CDI unit sends out the ground either when the oil pressure switch removes a ground from its lead to the CDI when the oil pressure is good or when the temperature switch sends a ground to the CDi unit when the engine overheats.

That being said.....if either of the above happens when at a pretty high speed, the CDI unit will cause the motor speed to down significantly, to protect the engine. You will not be able to go fast.

It sounds to me, that you were able to go fast and the speed did not automatically decrease. If that is the case, then the ground may not be coming from the CDI unit.

If you have a side mount shift box with the alarm in it....has anyone taken the box apart recently? If so, when the shifter is moved forward, it may cause something to ground the alarm lead inside the box.

If you have a separate key switch assembly, there may be corrosion built up in one of the connections in the 14 pin (round connector) at the engine or one of the connectors at the end of the wiring harness at the dash.

If your speed did automatically decrease, then there is probably a problem with the warning lights.

Mike

Dear Mike. The speed did not automatically decrease. I took off the speed and sailed slowly for a few min. Then i wanted to spped up a little, and the alarm tone sounded ( not beeps, but a constant tone) everytime i went from idle to more speed. My mechanic started the engine up in his garage and it has run for 4 hours between idle and 4500 rpm. No alarm signal and the engine just ran smooth through all the tests. He meassured and found all ok, according to his knowledge. The oilpressure fell to abt. 1 kg. He is not sure what the oilpressure "normally" should be in this engine, but 1 kg is not alarming, he informs me. Today he uses oil 25/40 in my engine. He suggested that he can use a more "fat" oil fex. 10/30. This is an "old car trick" he tild me, and asked me to check with you what you think of the oilpressure and his thought to use thicker oil ? Tomorrow he will open the side mount box to check as per your suggestion.
Thanks again Mike -

At 950 rpm oil pressure should be at least 1.5 kgf/cm2. There is no spec that I can see for higher rpm. Normally, I see oil pressure goes up with rpm.

You should not have to "thicken" the oil. That would just be covering up the problem.

You have at least four basic things that will affect oil pressure in this engine...
1. Oil strainer is clogged (strainer is in your oil pickup tube in the oil pan)
2. Oil pump is faulty
3. Oil passage is clogged/restricted (depending on where it is restricted..it could raise or lower the pressure)
4. Oil filter is clogged.

Have him clean off the oil pressure switch and take it out on the water and see what happens there. You probably will not get it to "fail" on a hose on land.

Mike

Hi again Mike. As mentioned my mechanic ( who's repair / dealership is not Honda licensed ) measured the oil pressure. The engine ran for 8 hours in a pool, between idle and raise of rpm, and the alarm did not sound. The temperature was fine and oilpressure a little above 1 kg. He changed oil ( no water in oil ), oil filter, cleaned various, and I took the boat out at sea. The engine ran 40 minutes for almost full throttle, and then several hours for low rpm's, and then abt 40 min for almost full throttle again. When i arrived at the port i took off the speed to idle, and when i gave a little more throttle the alarm sounded again. The green light disappeared ( no red light however), and back in idle the alarm did not sound any longer. After speeding up and down for abt. 2 minutes with the alarm sounding every time i had more rpm's than idle, the green light was back and the alarm did not sound any more at speed higher than idle. So it seems "overheating" indication, even for a very short while <? And why only after going from high RPM to idle ? Thanks / regards

The green light turning off indicates that the ECM thinks you are losing oil pressure.

One thought on why the alarm sounds when you have the boat moving on the water....probably your rpms are higher and the oil pump is trying to pump faster. It is possible that there could be debris in the oil pan and it is getting sucked up into the pickup tube, plugging up the screen....and blocking the flow of oil.

I assume you are using the correct Honda oil filter? Also, I assume that the mechanic cleaned off the oil pressure switch. Could be a bad oil pressure switch....

If you want to be sure that the signal from the oil pressure switch is causing the problem.....

Run the engine and make sure the alarm will sound. Then disconnect the wire from the oil pressure switch and run the engine the same way again. If the alarm does not sound, then it is definitely oil pressure switch related.

Then you just have to figure out if it is a bad switch or bad oil pressure. You already said that the oil pressure goes down as the engine rpms go up. That is not normal.

To get the oil pan, you have to remove the lower unit then the midsection of the engine. It is straightforward by it takes some time.


Mike

Hi again Mike.

As reply to your last questions : Oil pan was checked and cleaned a couple of weeks prior to this problem occured. My mechanic did not use original Honda oilfilter i understand. Oil pressure switch was cleaned.

Following above, i took the boat out again. The same story, as first time. Only this time, the green light went off for maybe 20 seconds. I went from idle to higher rpm’s a few times and the alarm tone disappeared and green light was on again. On land i checked the oil and all ok. 5 days later I took her out again. Abt. 25 minutes for close to full throttle. Drifting while fishing with the engine stopped. After moving position a few times, the alarm starts to sound with the constant tone. Not for long. This happens a few times. 1 time with the green light off the controlbox, but no red light. Then suddenly a “new sound” back from the engine. The sound was like a “rattlling”. Not at idle, but a little above idle this “sound” begins, and it sounds higher and higher the more rpm’s I go up. So I went towards shore at + -2500 rpm’s, still with the “new” sound from the engine, but no alarm tone and no red light on control box and green light on. I had then 2 – 2,5 meter waves, so I kept this speed, until within mobile phone network was on, and I gave a little more speed ( abt 3000-3500 rpm’s). Suddenly the engine stopped. When I tried to start it, it turned 1 round without starting, and then it couldn’t turn anymore. Like if no power, even there is full power on the (new) batteries. Following it only “clicked” when I tried to start it. After 10-15 min waiting, it could turn 1 round again, without starting, and then only “click”. So as if no electrical power, even the batteries are fully loaded.

My mechanic has now added new electrical cables, checked batteries are correct and fully functional. When he try to start, the engine goes 1 round without starting, and then it wont pull any longer, it only "clicks". If he waits, then at some point there is "power" for 1 round more, but the engine don’t start. He suggests the problem may be the start engine and proposes that i buy another - even the present one only has been on the engine for abt. 30 hours use. In such case, it is another problem, and not connected to the initial problem i suppose. Can you think of any other reasons, somehow connected with the alarm tone and possible low oilpressure, which can cause the engine to react as it did ? Thank you so much in advance Mike -

If there was truly low oil pressure, there may now be internal damage to the engine.

I assume the mechanic did a compression test at this point to see if anything has changed?

l wonder how it cranks without the spark plugs installed? Is it hard to turn by hand with the spark plugs out?

I have never heard of it on a 90 but the 225 has had some issues with the thrust bearing going out. That can cause low oil pressure.

Mike

Hi Mike


Your commentsare much appreciated.



The motor turns.Both by wrench on crankshaft, as well as easily by hand without spark plugs. Mymechanic is sure the start engine is broke. He “tested” it today by some kindof power tool.



Photo 2 showsafter the start motor is removed. The screw driver points at a thin crack inthe start motor. Do you think such a “crack” could cause the “rattle” sound Idescribed in my last email ?



Attached alsophoto 1, showing after removing the start motor. The oil below is “normal” butin the top and of the hole there is a little “substance” which can be removedby finger - which my mechanic described as “waterish muddish salsa” ( see photo1 ). He is not sure how/why the engine may produce this “salsa”, but somehow abit of water is coming into the oil. The engine is mounted a bit low on theboat ( even I raised it as much as possible), as in a little rough weather, thewaves/sea goes beyond the line to the cowl. Particularly when not planning andat “sudden” stops. Im not sure if this can cause water to intrude ? Aftersailing, I do not really see significant signs of water inside the cowl.



Can this somehowlead back to the initial problem with the alarm tone / possible low oilpressure ?



My mechanicsuggests me to replace start motor, change to new original Honda oilfilter (even though oilfilter ( not original Honda ) was changed 2 times within 2months ), new spark plugs ( which can you recommend ? ), thermostat.

I am willing tofollow his suggestions, but would like to ask your advice / comments ?



Thanks again andbest regards

If the starter is getting full voltage but can not crank an engine that does not have spark plugs, then it is most likely bad.

I don't think the crack is the cause of the rattle, but stranger things have happened.

I can not tell a lot by the pictures, but I can tell you that there should not be oil in the flywheel cavity. It is hard to tell how the water got in there. If you have signs of water/mud inside the rear of the engine casing, it is possible that water got in the flywheel area from there....especially if you keep the motor tilted all the way down when it is sitting in the water. It could also getting in there from a compromised shift shaft seal #29 http://www.boats.net/parts/search/Honda/Outboard Engine/2004/BF90A4 LRTA/SHIFT SHAFT/parts.html
or drive shaft seals parts #13 http://www.boats.net/parts/search/H... LRTA/TIMING BELT COVER MOUNT CASE/parts.html

Of course, once water got in there and started things rusting, it could have rusted the crankshaft, then compromised the crankshaft seal or could have rusted one of the block plugs that may be on the bottom of the powerhead (not shown in any drawing).

Once all that stuff happened, then it got to the starter and finished that off.

That is only one scenario, it could have all started from the power head....who knows without pulling the powerhead.

You do need to get that liquid out of there and spray some lubricant in there to minimize future rusting.

How is the compression? Leakdown?

Use only NGK DR7EA spark plugs.

Mike

Mike. The powerhead wastaken off first time 4 months ago and the lower part of separated, cleaned andput back together again with new parts. The powerhead was taken off again 2,5months ago and the lower part separated. The 2[SUP]nd[/SUP] time due to mymechanic did not notice the problem with the leaking tube on the mount casebefore he started it up after having had the powerhead off the first time. The transsionpiece from the water pump to the engine, with a metal pipethat goes out to the water control beam. The pipe was broken and hadleaked water, which had entered the engine, causing a block and partly corrosionin the lower part. The engine was separatedand cleaned in all sections. A new flywheel/hub, new case mount, new start motor,new power trim relay, new dipstick/tube,new mount case + oilpan gaskets, water pump impellers, filter,seals and othergaskets, ignition coilassembly, was replacing the damaged parts. Following this, the engine ran greatand without problems for abt. 30 hours until the alarm tone issue, andfollowing the last problem. The sailing season prior to this one, the powertrim was replaced. So I put a lot of money ( abt. 7.500 usd ) and a huge numberof hours and miles of driving into the repair of engine the past couple ofseasons, so im not ready to give it up as soon most parts have been replaced J.



As I understand mymechanic now, the engine turns “normal” both by hand with wrench on crankshaft( with plugs in ), and “normal” just by hands with plugs out. There are nosigns of rust / water/mud inside the rear

of the engine casing,as well as no signs of rust in flywheel area or below ( from what can be seenthrough a hole ). Only this very limited “substance” in the top of the flywheelarea which is as described – a greasy mud mass.

I suppose only 1thing to do, is to take off and separate the lower part again, clean it and puttogether again with new gaskets,

filters, oil etc.,and add a new start motor and see what happens.

May I ask how manyhours an experienced Honda mechanic as per your estimation ( + - ), would use for takingoff, separating, cleaning, and put an engine like mine together again ( if nosurprises along the way ) ?

It may be worth forme to find an authorized and experienced Honda mechanic, even I would have todrive a long way. I will ask my mechanic about status of compression andleakdown and revert again.

Will you be so kindto specify to me which gaskets, seals, and others I should have changed in thissituation, for sake of good order ?



Thank you very much for helping us Honda enthusiastic, but ignorantpeople !

after read all those post,Why Don't you dis assemble haul engine and make sure, Because its sound like to me their is some problem related with oil issue,Low oil pressure is bad sign,So if you are going to open all bottom parts i suggest to dis assemble engine part also of course it will consume more time and extra gasket, But it is better to Make sure the all bearings are ok. before entering that step, carefully inspect the oil pan, oil pump, and oil filter for any metal derbies, If no sign of that check oil pump and pressure relief valve,

wajira

Hi Wajira. I plan to ask the mechanic to lift out the motor block and disassemble the lower part(s). As im not familiar with such operation and the terms of this, which part(s) of the motor block do you suggest to have checked and for specific for what ? Thanks for your advise and input..

It is hard to estimate how much time this really should take.

Fortunately, the 90's do not have a lot a problems so I do not have a lot of practice with this model. But here is some reference points.

When doing warranty work, Honda has a specific amount of time that they pay us to do the work. To pull the powerhead and change the bottom crankseal....they pay 8 hours.

I supposed if you had all the tools ready and everything is perfect, it could be done in 8 hours.....as long as the tech did not breath, take potty breaks, etc. Unless a tech has done a lot of them and developed shortcuts and has a helper, it is almost always impossible to do it in the time the Honda will pay. You can get a little more time paid, if you have a good case to plead.

I have only pulled one of these once....6 years ago...with no helper. I looked over the workorder...it also included pulling the lower unit apart to inspect it due to some shifting issues. When the motor was shifted, the prop shaft did not move. The lower unit was ok except for a worn clutchdog. And that was not the problem. To make a long story short, it turned out that the splines on the flywheel had rusted and the vertical shaft ripped them out.

So I pulled the engine to change the flywheel and the engine needed a good servicing on top of all of that. So, a lot of the time is investigating time, but we charged them 18 hours.

I would think your guy can probably do it pretty quick, since he has taken it apart a number of times already.

I would change all the seals that you see once the powerhead is off. There are two that the vertical shaft goes through, one for the shift shaft, maybe crankshaft (depending on what it looks like). There may be more. You just have to go through the parts diagrams and examine the motor when you pull it apart.

Don't forget new water tube grommet and exhaust tube gaskets.

If your guy does not have a Honda shop manual, I highly recommend that he get one, so that everything is properly torqued and sealed properly. http://marine.honda.com/support/manuals/shop-manuals

Mike

Hi Mike - and others following thisthread. Mainly as an update for Mike, who really put so much effortinto helping us without proper knowledge. I found a new mechanic who seems toput more efforts and much less "hours" into making a goodjob on my engine. I ordered a new basket/seal set for the engine, aswell as some other stuff i thought necessary. My mechanic took apart the engine, and just informed methat allthe main bearings and con bearings are defective/damaged. He will check thecost for grinding crank and bearings in oversize. Could this problem,relate to the alarm problem re low oil pressure, starting this thread ?
Thanks in advance / regards

I would think it is definitely related. The question becomes.....did it cause the low oil pressure or was it because of the low oil pressure?

Since the mechanic has the engine apart, now is an ideal time to make sure that all of the oil passages are clear.

Mike

I have had ths exact problem on my 2009 BF90, The constant alarm is a sensor in the water separator, mounted on the very front of the engine. Without any tools it is possible to pull the separator out and remove the fuel lines from the cap. Empty out the fuel and your alarm will stop. I recommend draining any other fuel/water separator you may have mounted in the boat as well.

hope this might help

[email protected], Not even close, Read Danethor's entire thread!!