Intermittent tell tale water output - BF75A

Hi guys - I got my engine hooked up yesterday and decided I'd give it a run today so I can start trying adjustments to get the throttle & gear cables set up nicely etc,

I seem to have a couple of issues though with the engine.

The first is that the water output from the tell tale only happens some of the time. I realise that running the engine without water being pumped through can cause serious damage so I am anxious to resolve whatever is going on here.

The first time it started, it ran for some time with no water coming out, then suddenly it started peeing out of the tell tale like it should have been. I'm not used to Hondas (previously had Yams) and I wondered if Hondas vary the amount of water they pee out for some reason? It was absolutely blasting out for some time - really powerful healthy jet, but then after running for 5 minutes or so the water output reduced.
There was another time as I recall when nothing was coming from the telltale, but both times when it has done this, I switch the engine off, and then water begins to pour out from it, even though it wasn't when the engine was running immediately before.

It's confusing me somewhat I must admit!! Is it possible there's something inside the engine in a waterway that is moving about and sometimes causing a blockage and other times not? I can't think why else the water output would be fine at some times but not others unless it's something like this, ie if the impeller was damaged then the flow would be reduced/stopped all the time, not sometimes.


The second issue is that the engine bogs if I try to rev it much. I suspect it's fuel starvation.
I've only just hooked up a new fuel hose from my onboard tank, and I rather think that the connector on the end of the hose where it attaches to the engine is not sealing correctly. I want to get a genuine honda connector as I think it's a cheap aftermarket one that's leaking air in, but are there other common issues that could cause this behaviour that I can easily test for?

Many thanks in advance

First, I'll say I don't work on this engine so this is mostly speculation on my part.

It's quite possible that you've called both of your issues accurately. The tell tale flow coming and going does indeed sound like something in the passage is "valving". You should take a look at the places debris could be caught starting with the two grommets and the fitting in the case they call a "joint".

Refer to illustration below and check items # 36, 37 and 10 to make sure they are clear. I can't tell you if it will be easy or difficult to get to that joint but it might hold the secret to your problem.

http://www.boats.net/parts/search/H... /ENGINE LOWER CASE + ENGINE COVER/parts.html

It is possible that you have a problem with the impeller but debris in the passage is much more likely. I've seen the drive key not seated right on many engines and this can cause intermittent "pump/no pump" behavior. It would be something to consider if you continue to have problems after checking the tell tale passageway.

By all means, check that the fuel hose connector is the right one. Even if it is, these can vibrate and cause the pin that opens the check ball to wear down and not allow the valve to open all the way for maximum fuel flow. A poorly fitted aftermarket connector can even pop off if it doesn't latch properly.

I see that there is much linkage, two fuel pumps and four carburetors so having them synced and all going to full throttle simultaneously is important. Other than verifying good fuel volume from your pumps, there's not much else I know of from experience to suggest other than to make sure your fuel filter (item #2 in above link) is clean.

Hopefully others with hands on experience with your model will have some better suggestions. Good luck.

Thanks very much for the helpful reply. Could you possibly expand on what you mean by the drive key? Is that like a woodruff key that the impeller sits on? Kind of makes sense if that's the case possibly.

I believe the impeller and so on were checked as serviceable by the dealer I got the engines from (it's one of a pair and this is the better of the two), and I know it has also had an oil & filter change etc. I've owned them a few months and this hasn't run for more than a few minutes in that time as it hasn't been on the boat.


Well I took the liberty of removing the stat housing to inspect it, since I've had ones with salty crud in before when previous people haven't flushed adequately.


Bit of a shock actually the amount of gunk in there:






Impressive! I should add most of this was from the housing where the hose flush pipe connects to, just to the side of the stat housing, but there was still a bit of gunk in around the stat. All of this is nice and clean now anyway!


I also removed the lower valve housing about 8 inches below the stat and cleaned that out. There was a small hole that was blocked in there but otherwise not too bad.


I also tested the stat in a pan of water before reassembling and it seems to work ok.


So I reassembled and started the engine after it has been sat overnight.
It peed out a very good jet straight away, and this carried on for a couple of minutes maybe, then the jet got weaker and stopped. I switched the engine off quite quickly after this even though the overheat warning wasn't on.
I thought I would let it cool for a few hours as I'm out for lunch, then repeat and see if it behaves the same way.


I've a suspicion that the flow is stopping when the stat opens, since it was fairly definite a couple of minutes or so after the cold start and I'm sure that could coincide. No idea why that would be the case though?

One way to see if it is related to the thermostat...is to take the thermostat out and start the engine and run it a few minutes and see if that makes any difference. Just remember to put the thermostat back in after the test.

If the telltail stops again, take some compressed air and shoot it back up through the telltail hole. If the flow resumes, then you have some roving debris. From the look of all the salt, there must be more in passages that you do not see.

As for the rev's. If you are trying to rev it up on a hose, the motor will limit the revs if you are doing it in neutral...to keep the motor from overreving.

Mike

Well, as bad as that looks, I've seen MUCH worse!

Yes, the impeller key is the drive component that connects the impeller to the mainshaft and is somewhat like a Woodruff. I've discovered through experience that it is UNWISE to reuse the drive key. They do wear and it can be imperceptible. If they get worn a very small amount, they will "roll" in the flexible impeller and not drive the pump properly. This can also damage the mainshaft boss where the key sits. So, always replace the key and not reuse.

You may be on to something with the pee stream going "soft" when the stat opens. I've seen impellers with only one out of five vanes left still pump and keep a pee stream going. But, it is obvious that one out of five ain't good and will be way less efficient. You could have something like that going on.

In addition, when these things start to "shed" impeller vanes, they break into pieces that tend to get in the passages and clog things up. If you try what Mike suggests, taking out the stat for a short test, make sure that you back flush in the block as good as you can if you haven't already.

Good luck, and keep us posted on your findings.

Good idea about removing the stat. Will try that I think.
I'm going to widen the pee hole in the plastic outlet as it's super narrow, and I can drill it at least 1mm wider, which will reduce the chances of obstructions slightly.

Re' revs, I don't think it's the engine limiting it but it's possible I suppose. It bogs (to stall point) and smokes soot (rich) if you open the neutral throttle more than a little bit, but if you then ease back a bit it picks up and revs quite well.

I think part of the problem is an un-honda branded fuel line connector, which does not seem a very solid connection (although drawing air wouldn't lead to a sooty rich smoke of course). I've bitten the bullet and ordered a genuine honda one for over £3, to my dismay.

Also, since I've only just got the gear & throttle control cables initially fitted without any adjustment I'll wager there's some tuning & adjustment that's really necessary on these to have the linkages and throttle butterflies etc at just the right points.
I don't know how long this engine was out of use before I got it either, so Ive no idea if there carbs might have gum/varnish in them. I'm dreading that prospect, but have ordered the honda carb book in preparation.....

Just been out and given it another run. Progress I think!


I'd drilled out the pee hole from about 2mm to nearly 5mm to aid the flow of water and reduce chances of blockages, plus I gave all the linkages etc a liberal spray of WD40 and worked them all back & forth many times to ensure everything is moving freely as it should be.


Started the engine and water blasted out nicely from the telltale. Carried out letting it run at a fairly quick idle (tacho not wired in yet) and the water continued to flow. I did some tweaking of the throttle stop screw on the bottom carb to raise the idle a bit initially as it kept stalling.
Carried on revving it, with regular short squirts of carb cleaner into the air intake.


After it had been running for some time I found that it actually was much happier to rev now. It seems like it sounds a bit rough to me but it's so hard to know what's rough and what isn't on an engine I've never really used before, and when your head is a couple of feet from an open intake that makes a huge amount of induction noise when you rev it!
Initially it was coughing each time I tried to rev, but after it had run for about 10 minutes it began to rev ok. I realised a moronic schoolboy blunder - where I'd thought the neutral throttle was making it run rich and bog, it was of course because I had pushed the lever into the choke zone while the engine was already warmed up (hangs head in shame).


Anyway - I ran it for the better part of 20 minutes in the water filled drum, and no hesitation in the telltale flow this time at all. Constant and strong stream of water. Plus it now appears to rev without coughing or bogging.


I think this may be a case of blowing out the cobwebs from an engine that's not been used for some time. The idle seems very smooth, and with the engine cover on, it's a pleasantly quiet motor (if louder than my 1999 F50 that I had before).


Will continue to give it a run in the tub each night I think and ensure it runs nicely and behaves well, plus I will get some sort of fuel treatment to go in and potentially help clean stuff (although I think they're mostly snake oil, there's no harm and you never know...), plus if I can get an additive for the water to help get the salt deposits gone I'll do that too.


So I'm a lot more positive now than I was earlier in the day, and that's not bad progress I think.

The next thing I need to address is that there are no lights on at the remote box, at any time that the ignition is on or engine running.


I understand that normally if the light goes out this means low oil pressure but I seem to recall my dealer telling me when I took the engines off him* that one of the control boxes of the pair had an issue with the warning lights, and that these hondas are notorious for something to do with the alert system being oversensitive, or giving false alarms or something. I forget the details now and I wish I'd written it all down at the time.


Anyway - possibly I hooked up the wrong one of the two I got, but with no lights showing at any point is there an easy way to investigate this? I seem to recall when looking at one point that these things use neon bulbs that use funny voltages and aren't easy to test or something?


*I got a nice deal from him - gave him my 1999 yam F50 low hours for a pair of 1996 BF75 high mile engines - so it was with caveats about the condition of these engines

Actually seafoam is one exception that I've heard nothing but good stuff about admittedly but not sure if I can get it in the uk easily, never mind the Isle of Man. Will look into it, but I think most of the things available locally are the likes of redex fuel additives.

Yep - I always flush with fresh water as well, and I used to do the same thing with my yam about disconnecting the fuel then running dry.

Cheers - I've got various manuals for the engine so hopefully the wiring of the remote box is included in the diagrams.

I've found seafoam on ebay, but most places won't send it to the isle of man alas. Sure I can get some though if it's likely to help smooth things out a bit. Pretty harsh at £20 a can though so I really hope it is worth it.

No way I intend to be using the boat without having functioning warnings for the engine so I want to get it sorted.
If something is faulty with the remote box then I do have 3 the same to try swapping or changing parts from if need be. Hopefully between them I'll have one decent one that works as it should!

Nah, it's carb engine (1995/1996 model). I've been trying to get a set of 90 carbs as that's the only difference between the 75 and 90 but just had the runaround so far.

kimcrwbr1 said:

You can get seafoam possibly at a auto part store or any boat dealer might have some.

Click to expand...

Can pretty confidently say that the auto parts places here won't have it (the main one on the island barely has anything useful), but it might just be worth trying a few of the boat places.

If you can't get Sea Foam (of which I too use a lot for fuel treatment) see if they stock LUCAS FUEL INJECTOR CLEANER. I use their products, including their injector cleaner, engine oil "modifier", transmission additive and even their power steering fluid for tilt/trim rebuilds. I have no scientific documentation to offer (they do) but I have always felt that their products improved the condition I was using them for. They are big in motor racing world wide and I would think you can buy the stuff just about anywhere. And, no, I don't own the stock...but maybe I should?

While running your outboard out of fuel is an accepted practice that I don't necessarily (lean burn on a hot day not good) argue with, I don't think you should stop there when putting a HONDA carbureted outboard away for any time more than a few days or so. I always suggest that the carburetors on a HONDA be drained completely to prevent scale and mineral deposits from forming in the critical passages at the bottom of the float chamber. Even for short term storage. Simply running the engine out of fuel does not get all of the liquid out of the chamber and, if there is ANY water at all in the fuel, that is where it will collect.

Don't "dread" the carb rebuild. Since you are getting the manual, it should be a piece of cake and the peace of mind clean carbs afford you on the water is priceless. Glad to hear you're moving in the right direction. Keep it up and good luck.

Thanks for the positive comments, and tips.

Gotta confess that while I do tend to disconnect the fuel line, it's rare that I use the drain on carbs. Point taken though.

My engineer did mention something years ago about disconnecting the fuel line and running to cutout having the slight potential for harming something or other in the engine eventually but I forget the details. This was after I'd quizzed him about the tapping noise my yam began to make at times, until I realised it was only a minute or so after removing the fuel line, and he explained the cause of this to me. He wasn't overly concerned about it being a bad practise as such but did say there was some vague potential for it to cause wear over time.

When I say about dreading the carb rebuild, I don't mean in the sense that I'm nervous about it, but just that stripping & rebuilding carbs is something I find pretty tedious, having done it a lot of times between cars bikes & boats over the years.

One thing that would be good to know though (other than seafoam) is any product that is really really proven effective at eating through varnish/gum if the carb is soaked in it, or used in an ultrasonic cleaner? May possibly get one just for cleaning small parts in general, but depends if I can get really effective stuff to use in it.

I just bought a proper paper service manual with supplemental bits as well. Bit expensive but it will stand me in good stead for the future, and the CD based versions are a pain to use since they're normally scanned in paper ones that can't be searched for keywords etc.

With this and the carb manual, plus a full running BF75 for spares I should in theory have plenty of happy boating for many years to come. In theory.....

Update time again - gave the engine another 15 minutes running tonight.


Started very easily from cold, even on the very small, very old lucas battery I had from my F50. Running it like this really seems to be helping blow out the cobwebs from the engine. Very briefly popped it into forward & reverse gears, although I can only do that for a few seconds due to the eruption of water that then leaves too little in the tub.


The pee stream from it was really solid until around the 10 minute mark or so when it began to lose pressure/flow, so I turned off the engine and left it while I did some other stuff.


I got battery terminals today, and a load of high current ring terminals, so I took the croc clips off my jump leads (really thick 41mm2, 2 gauge cable), and put the terminals on both ends. I bolted them up to the engine power leads, and the battery, and cranked the engine.


Cranks over very nicely and fired up no problem. I took the caps off the spark plugs and cranked the engine a bit to see how quickly it cranks and the combination of the new 105ah battery and the thick leads really whizzes the engine over at speed. Healthy starting assured, and this is great because it means I can move the 2 batteries to underneath the console. This will definitely help balance the weight of the BF75 and BF5 on the back by moving 30 kg or so forward rather than it being astern.


Made an interesting reminder of just how crappy the clamps on jump leads can be compared to a solid connection. These a decent quality 3.5m Clarke 41mm2 leads, but hooked up to the engine with clips it was sluggish and reluctant to crank over. Swap to proper battery terminals and the right size ring terminals on the other end (with m8 bolts to connect to engine wires) and it goes at real speed! Huge difference and demonstrates the importance of a good electrical connection for anything with a load to feed.


Picked up 3 gallons of vinegar to help flush the salt out, so I need to displace a lot of the water in the barrel so the vinegar is not diluted too much.


Also, I might just have found me a set of sensibly priced 90 carbs to upgrade from 75 to 90. Now that would be nice!

Got a chunk of the console wiring harness made tonight. Tedious as hell to do, but it will make things easier to have it labelled nicely and measured to the correct lengths & soldered/heatshrink covered etc etc.

I love it! The joy that boats can bring. Even when a guy is having trouble with his water flow, he's off and running on the wiring and making it all ship shape! Us boys would be lost without our toys. Well not lost maybe but a bit of the shine would be taken off of life without a boat or two or three or... to tinker with.

Looks like the carbs might get you some more ponies but, you know, as we all do, the old saying..."Mo ponies Mo monie

But, if you can afford the gas, then MO PONIES TO YA!

Good luck with the vinegar flush.

Ha ha - thanks.

Strangely, in the Honda Manual, the fuel consumption figure for the 90 is lower than the 75. Not sure on the rationale of that or if it's just a missprint or something. Unless it's to do with the 90 needing less throttle to provide the same performance as the 75 or something. Who knows.

I'll only get to use the boat maybe 10 times a year I suspect, and compared to the 2 stroke 75 I had years ago it'll be more frugal anyway so while I don't have much spare money I can live with the occasional tankful in return for the peace of the sea, and the potential of a fresh caught dinner.


I've got a big list of jobs still to be done but I'm itching to get a test of the boat within the next few weeks before winter comes (even though we haven't yet had a summer here).

And yeah, too many toys and projects (well, can never really have too many), but I've 2 cars, a bike and a boat all in need of remedial work at the moment, and working on the boat all the dry evenings has stopped me doing photography like I often would be.

Can't have everything and we're lucky to have these things in the first place.

You know that horrible moment when it dawns on you that you've spent ages doing a job that really wasn't necessary at all?


Yeah, I feel like an idiot now. I just found that on the really old & manky looking remote box that was on the boat when I got it, that it has the separate wiring harness for the gauges attached to it and I'd never even noticed. How dumb do I feel now after spending about 2 hours last night making a new harness!!!


On the plus side, I tried starting the engine with each of the honda remote boxes that I've got (two came with the pair of engines, and one was on the boat when I got it), and out of 3 of them there is only one which displays the green warning light.
The other light I hope only comes on when the engine gets hot, as that does not light up on any of the three.


It's a shame as it's the scruffiest, mankiest looking one of the 3 that has the working warning light, but possibly I can swap the casings, or else troubleshoot the wiring of a non working one against the good one to figure out why the lights don't work. At least it confirms the oil pressure is fine. I think.

I have just one question...what is the root of the word "manky"?

Not sure the origins, but here's what the dictionary says:

http://www.thefreedictionary.com/manky

Just kind of scruffy and not good is my use of the term.

Anyway, oil pressure light is good now, although it has to be said they're awful LEDs that they use as they're hard to see in bright sunlight. Not that this will pose a problem generally without our climate here but still...

Have been running vinegar through the coolant system today, albeit very diluted. Not sure if it poses any risks to any parts if it stays in the sytem but the telltale seems to be getting better and better but still the odd time or two when it just stops for no apparent reason.

Done some wiring on the boat today as well, so it's all coming on nicely!
Fun dealing with electrical gremlins now though. Tried hooking up the fuel gauge today and I cannot get it to give a sensible reading at all!