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Bf135 2011

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Mikala777

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Help!!!! I’m in the Marshall Islands w o a real
mech here!! I have one motor dropping off w a high temp alarm after a few min at 4-5k rpms after putting motor in neutral it will resume to norm ... I can troll all day at 3-3300 rpm w o a problem but if I throttle up to 4-5000 rpm it will drop off! I replaced t-stats and 2 sensors on housing , replaced all water pump parts , descaled motor replace anodes (?) replacing wiring harness not sure if that’s an issue but old one was corroded at connectors ? Is this a water pumping or sensor issue ?? This motor does not piss as good as other but not so sure it that matters I did pull off hose and let it piss while idle seems to not have a hose clog? Any thoughts on next trouble shooting ?o2 sensor ? Could this cause this to happen ??? Mike
 
Hi Mike,
Your description of slightly reduced flow compared to the other outboard makes me think it could be overheating. When you run at higher rpm you're burning more fuel and producing more heat so a flow issue could have it cooling ok at lower speeds but overheating at higher engine load.

I wonder if the extension case water tube grommet might be leaking?

https://www.boats.net/catalog/honda...5hp/bf135ak2-xa-2007-and-later/extension-case

Look at the "window" with the pump and tube in the link above. See how it references page F4?

Below is Page F4. Reference item 12. If it leaks, it could cause the symptom you describe.

https://www.boats.net/catalog/honda...2-xa-2007-and-later/water-pump-vertical-shaft

Good luck.
 
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Thanks for your direction!! I've heard that from someone else ...even though it runs all day at lower rpm?? could a bad O2 sensor cause this ? I think its water pumping issue but was told id have to remove motor's head to get to that grommet and water pipe?? do you know if that's true??
 
Well, I don't have any experience or a manual for this outboard. I tried to find a better depiction of how that grommet was placed but those two pages from the boats.net parts book was all I found so I can't give you a definitive answer. My first guess is that it may be accessible without removing the power head but it's just a guess and I could be WAY off the mark.

Yes, as I said before, if you aren't getting the maximum flow to the engine due to a leak, it's entirely possible that it won't overheat during low demand operations but will tend to not cool as it should when the engine is under heavy load. It's very similar to an auto with a partially clogged radiator.

I do not think an O2 sensor would cause it to overheat or sound the alarm. Have you checked it for fault codes? I don't know if that model can be "shunted" to retrieve codes. If not, you will need a Dr.H to plug in.

Hopefully one of the real gurus that help out here can offer you better advice. In the meantime I'd be looking at boat transoms for big Hondas. You may run across someone that has diagnostic capabilities that could help.

Good luck!
 
As jgmo said, it could be a leaking water tube grommet. Remove the lower unit and midsection, you will then see a clamp holder retaining the water tube. Remove the retainer plate and then the water tube and then inspect the grommet and replace if necessary
 
iang6766 said:
As jgmo said, it could be a leaking water tube grommet. Remove the lower unit and midsection, you will then see a clamp holder retaining the water tube. Remove the retainer plate and then the water tube and then inspect the grommet and replace if necessary
Click to expand...

thank you , I"ll try to drop lower , what are you referring to mid section? does this access the grommet?
 
Midsection is the housing between the oil pan and the gear case, once you have the gear case off, remove the lower mounts and the
extension case. the water tube is mounted in the bottom of the oil pan, it's self explanatory on e you do the job
 
was able to see water pipe and grommet , they looked ok , attached hose to water pipe and saw no leakage around grommet..question. could it be possible that water pipe is not seating on pump unit as I slide lower unit on?? I actually replaced impeller and o ring/gasket while I had it off , has anyone ever experience this ???
 
That was just one more thing to check, it's highly unlikely the tube is not connected to the water pump. Are you sure you have your thermostats in their correct place, 50 degree should be on the cyl head side and 60 on the block side. Next thing that will be very useful is to run engine with dr h to see which temp sensor is indicating overheat, there are 3 in all.
 
I agree with iang's advice about the pipe and, if you're not sure, go back and check your t-stats.

Not trying to insult you but are you positive that you put the impeller in with the vanes pointing in the proper direction? It happens quite often that a guy gets that wrong and the engine doesn't cool properly as a result.

Also, I am not a big fan of using a new impeller in a worn housing and cup. No matter how good the old parts look, they are worn and 100% pump efficiency will never happen mixing worn and new parts. If you used the old housing and cup you may want to go back and reassess their condition. You're going to be relying on that pump for at least 2 years so spending the extra $buck$ for the complete kit really just boils down to what I call cheap insurance.

I like the suggestion of looking for a possible faulty temp sensor although I know you said you're in a different setting than we are.
But a lot of Honda owners have the Dr. H software for a laptop so it never hurts to ask for help from a fellow Honda owner. You just mind stumble across one they will plug in for you.

Hope you find the problem soon.
 
I just ordered a pump kit to make sure that there's no mixing new w old thanks , double checked impeller direction, put it back together again, ran boat up to over 4000 and a min later, motor shut down w high temp alarm for A min or so till it cooled down . then it would start or run back up to lower rpm. checked t stats when I checked pump, I installed them according to book and diagram...ordered new ones as well as pump. this problem has been an issue for a long time ,keep thinking it has something to do with water circulation ??? guy here said his 225 Honda was doing similar thing but changed the O2 sensor? so do I spend 400 on dr H? will this dr h tool tell me wth is going on with motor while at idle or will I have to run motor up on water till problem happens?? Im on an island Kwajalein Army base with no Honda shop within a few thousand miles , thank you all for your help!
 
The reason I suggest dr h is because I have had a faulty sensor, so dr h will tell you which one is setting off the alarm, so all the temp sensors are the same, you swop it with one of the other two and see if the o/ heat follows, if not then you know you have an internal blockage, if it does then simply replace the faulty sensor
 
Not sure I'm helping you very much if you end up spending $hundreds$ but with no solution. The Dr. H is a pricey luxury but in your case, where you're the only one that's likely to get the job done, it might be a really good buy. I know that if I had a big, later model Honda, I would have one even though I live in the city. That's just me though.

I suppose that, if the O2 sensor had the engine running very lean it MIGHT contribute to an overheat condition. I don't know. But with the computer monitoring the sensor, it should log a code. It should also kick a code for overheat. If you can shunt the diagnostic connector to retrieve codes, you should try that.

Electronic engines can behave in odd ways sometimes due to faulty wiring and/or connections. Checking as many power connections and ground points as you can discern is a good idea while troubleshooting a problem you suspect may be electrical in nature. Also, one thing I do on autos is "wiggle test" wiring to see if anything jumps up as I do so. But it's not as easy to do on an outboard sometimes.

Another thing I routinely check is something known as "alternator ripple". An alternator that has diodes going bad will start putting a.c. current into the charging system. This is called ac ripple and can cause havoc with 12 volt dc electronics. The good news is that it's exceedingly easy to check if you have a decent DVOM. You simply set your meter to the ac scale and check the voltage across the battery with the engine running at various rpm. IE: idle, 1500, 2500 or higher.
You shouldn't see more than 25 millivolts ac (0.025). Most alternators will read 0.000v ac if the rectifiers are sound.

But checking the "basics", as you are, FIRST, is always best.

I APPLAUD you for going back and checking/replacing the pump and tstats. I would also recommend a really thorough cooling passage back flush with a commercial cleaner like Salt Away or white vinegar while you have the old pump in. You should use a trash can to run the outboard in and dose it with cleanser. Then let soak and then remove t-stat housing and pump and backflush. Make sure you have all the new seals and gaskets on hand.

Here's hoping that your efforts pay off!
 
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AgainThank You!!!! I actually back flushed engin w dynamic descaler as directed by a Honda mech about two months ago when it was starting to get worst, imsure it helped some but did it stop problem ! Lol ... I pulled off mid section to ensure the water pipe didn’t have any holes and to make sure grommet was good . Undid water hoses I could to again flush wo t stats in it . I also did run boat in water before this midsection removal wo T stats , swapped out ecm’s and used a laser temp gun . It shut down again at 3000 rpms and thermo stat area was at 105-112 degrees and pisser still wasn’t as good as my good motor . I did order Dr H today!! I know there’s a sensor up by electric box ect 1, I never swapped it out , didn’t want to do it on water but should I wait till the dr h arrives ???
 
If your motor is fitted with the fuel/water separator it has got a sensor inside that can also trigger the alarm when last did you check and clean it. some motor were not fitted with the sensor inside.
 
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Tegweni may have a great idea there. You could certainly check and clean water separator. But I would wait for your Dr. H before doing much else. Then you should be able plug in and compare the readings from each temp sensor to see which one doesn't match the others or see if any codes have been logged. I hope it's that simple anyway.
 
Still waiting for Dr. H but I have installed new t stats and pump rebuild kit and put everything back together and filled tub, started motor and noticed that the pisser is going harder now. hope it as the impeller housing that made a difference? will wait till dr. h to drop back n ocean to run it up .I have installed a new pump and all the pats 400 hours ago and I still had the high rpm issue /high temp shut down alarm but at 5000 . seems to have gotten worse at lower rpm ...
 
Not sure what you're question refers to but...

....Do you see steam or "white smoke" smoke from exhaust? If water hits exhaust where it shouldn't that's a sign of that happening.

If water is entering combustion chamber then the spark plugs usually look very clean compared to others. Just don't remember seeing that thread you mentioned.

What you do know now is that the water pump kit installation pretty much ensures that you're getting 100% effective pumping. That eliminates one question about what has been going on.

I know this is probably eating at you but wait for your software and do the scan before worrying about "what ifs".

The real problem we're all up against with figuring out outboard issues is the open cooling system. In cars, you can pressurize the system and know, almost immediately, if there is a leak and, in most cases, you can pinpoint it easily.

A compression test on an outboard is one of the most effective tests we have but it doesn't help all that much with diagnosing cooling problems.

But, with the Dr.H and an infrared temp gun it should be a bit better than the old days.

Hang in there! I can tell that you are a guy that doesn't give up and tenacity is about 70% of getting to bottom of hard to solve problems.
 
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