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Help please on BF50 electronic choke solenoid

H

haltabb

Member
Having problems cold starting my Honda BF50. After reading multiple posts, I believe it is my electronic choke solenoid. I understand they gum up. My questions are:

If I push down my key with the engine off but ignition on should I hear the solenoid click. If so, it is not making any noise.

Where is the solenoid? There are 2 electronic connections to the carb. One is round and seems to go into the air intake. The other appears to be attached by a grommet to the carb. Both are on the top of the carb. Any help on how to clean the solenoid would be greatly appreciated.

Was there a Service Bulletin regarding hard to start 50 HP engines from Honda? If so how can I find it?

Thanks for all of the help.
 
If the serial number for the 50A is between BAZS-3400001 and 3701268, Service Bulletin #59 changes the Starting enrichment valve and the float bowl of the top carburator. This all depends on which ones are there now.

Check with your local dealer, if your motor is still under warranty, it should be covered if it meets the criteria.

Mike
 
not trying to impune your post but.............I have an EFI 50 that starts every time....even months between use.

Again, I am just bragging.

Mike
 
My BF50A does not like cold starts either.
My choke solenoid is activated by lifting the fast idle arm
to maximum.
If the motor has not been run in several days, it sometimes takes a couple
of 5 second cranks to get it going.

Once running for a few minutes it smoothes out and will run like a top all day. :)
 
dark_star

You have a slightly different version of the 50. Yours has an actual choke the closes down. You have to advance the throttle and activate the choke (by raising the fast idle arm all the way) to start.

Haltabb's is designed so that you just turn the key...no choke...no advanced throttle.

Mike
 
Mike,
does the start up at high rpm's cause any damage ?
i've been starting the motor same way for years
only way i've known.

Scott
 
Scott,

Once the motor begins to start, then back off the fast idle lever. You may have to quickly move it all the way back up to "tickle" the choke a couple of times to keep it going. But bring the lever down to a lower speed (not all the way back) unit the engine smooths out.

Mike
 
Hi,

Mine must be the same as dark_star - its a 2000 Honda 50, if I lift the fast idle arm all the way it wont start. If I go back and use the pull choke - it starts everytime. I then have to push the choke in almost immediately and then I lower the lever slowly.

Maybe I have something hooked up wrong - I installed the motor, lever and cables....it would be nice not to have to go all the way back to the engine :)

When I lift the fast idle should something be happening that I can see? Is there some sort of solenoid?

There is no button to push in with the key.

thanks
 
You still may not be lifting your fast idle arm high enough. When you get it up all the way, grab the shift lever and your fast idle arm and squeeze them together. They should almost (and in some cases do) touch. If the key switch is in the on position, you should here the click.

Mike
 
Hi

went and tried this morning. Pulled the Lear all the way up.Touching

No click....unless I have cables in wrong....or ssolenoid issues.

thanks
 
hondadude said:
If the serial number for the 50A is between BAZS-3400001 and 3701268, Service Bulletin #59 changes the Starting enrichment valve and the float bowl of the top carburator. This all depends on which ones are there now.

Check with your local dealer, if your motor is still under warranty, it should be covered if it meets the criteria.

Mike
[/QUOTE
My.BF50A6.is.having.the.same hard.start.when.it.is.cold...It.is.covered.by.the.Service.Bulletin#59.indicated.above.,but.is.NOT.covered.by.warranty...How.can.I.troubleshoot.the.problem...I.dissassembled.and.cleaned.the.carbs.and.blew.air.through.the.SE.passage.leading.to.the.SE.soleniod....What.is.next.step?
Click to expand...
 
First thing to do is check the lettering on the SE valve.

The old SE valve lettering started with CL followed by three letters or numbers. If it starts with HG, then it has been updated.

Also on the carburetor bowl on the top carburetor, there is a number (jet size) engraved just above the drain nozzle. The old jet number was 80. The new one is 78.

So, if you have the old parts, these are what need to be ordered.
16023-ZW4-F01 SE Thermal Valve Assy
16023-ZW4-F01 Float Chamber Set (includes a new o ring)

I highly recommend rechecking the cleanliness of all the carburetors. They all have a lot of passages that need to be clear. There are several threads on the forum that get pretty specific to the cleaning of the Honda carburetors.

Once all are cleaned and you have the updates for the top carburetor, you need to vacuum balance the carburetors to make sure all cylinders are firing evenly. Then the idle should be set. Should be 950 plus/minus 50. I usually set it on the high side near 1000 rpm.

This is when I normally attach a link to where you can purchase the Honda Carburetor Manual...but it seems that I can not find any on Amazon or ebay from Honda at this time for some reason. https://www.amazon.com/Honda-Marine-Carburetion-Service-Repair/dp/B00D2Z1AFO

I hope some of that helped.

Mike
 
Thanks Mike. I will check on Friday as the boat is back in the slip. Really appreciate the help. Also, can you help me understand how the SE system operates? Since I completely disassembled and cleaned all three carbs - I understand the hose layout, but not how the choke (SE) system operates. I also replaced the jet (tube) in all three carbs as one of them was split.

In starting on a cold day - do I hold in the ignition key while cranking the motor, or should I be doing something different?

Don
 
Briefly, you do not hold the key in when you start the engine. It does nothing for this carburetor arrangement. As well, you do not advance the throttle. Doing so, will make it really hard to start.

Pushing the key in, was used when there was a physical choke.

The SE valve, when the engine is cold, allows a richer fuel/air mixture to be fed through the carburetor at start up. Once the engine starts, the idle should be relatively high. The SE valve is powered up and it heats up. This causes the needle to push out of the SE valve closing off the enriched mixture, allowing the carburetor to work, using its normal passages.

As the needle closes, the idle comes down to normal idle.

Mike
 
Thanks again Mike.

I see - said the blind man! Makes sense to me now. So, if I understand correctly - this is an "automatic" choke, and it works each time the cold engine is started.

Question - what controls the SE valve, or is it simply connected to the battery when the engine is switched on? How do I tell if it is working? You mentioned a higher idle speed at start up (cold engine) - what would this higher rpm be around?
 
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The SE valve on your 50 is powered by voltage from the ICM when the motor runs. To check that it is working, you will need to do two things. First..make sure that it is getting power to it when the motor is running. Once you know it is getting power, you can remove the SE valve and connect 12v directly to the SE valve leads. It should heat up and the plunger/needle will move out from the main part of the valve. I am not sure what the measurement difference is off hand, but will probably be about 1/4 inch.

As I said before, it is closing down on the opening that it is going into. So, if the valve is not functioning, but is in the "cold" position, the engine will start, but the idle will never come down to normal.

I do not know what the start up rpms are. You set the idle when the engine is fully warmed up and in neutral. I have never measured the idle at startup....it doesn't really matter....as long as the engine starts and the idle ends up where it should.

Mike
 
Mike:

I checked the numbers on my engine and it appears that SB59 was never complied with, since I have the carb bowl with "80", and the SE coil is the one beginning with "CL". So, I am now ordering the required items.

One question - regarding the mixture screw - when cleaning the carb, I was not able to remove the screw as it has the limiter cap installed. So, what is your recommendations as to how to proceed regarding the mixture screw?

Also, everytime I go to start the engine for the first tiime each day, I have to pump the primer bulb at least 6-7 times. This seems abnormal, since on my Optimax 150, I've never had to pump it in six years. Recently I replaced the fuel line from the tank top the engine with an after market assembly because I suspected the check valve in the old one was leaking. But this did not change the need to prime the fuel line. Any thoughts on this situations?

Again, "hondadude" - I really appreciate your help!

Don
 
Mike:

After checking part numbers on Boats.net, there seems to be a discrepancy with the part number for one item that you referenced in an earlier post. Here's what I found for my engine - which is the BF50A6 model:

16130-ZW4-H01 BYSTARTER, AUTO (Honda Code 7509862) - ​(this is the solenoid coil, item #18 in the parts diagram)
16023-ZW4-H01 CHAMBER SET, FLOAT (Honda Code 7509771)

So, how can I confirm the info about which one is correct? I just want to be sure SB59 applies to my motor; so can you re-verify this again for me?

Thanks again.

Don
 
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Hey Don, In my first season with my BF50, I struggled with poor first start each day . I spent approx. $400 at the marine mechanic . Changed out the SE valve , cleaned carbs ( twice), fuel line , primer bulb , filters etc . I then discovered this forum. Mike / Honda Dude helped me out . Here is what worked for me , point the primer bulb arrow facing up and pump till it is full and hard. Starts every time now for last two seasons . Also the purchase of the Honda carb manual has been invaluable . There is a you tube video showing how the SE valve works on a moped , it describes the operation and shows how to test it .

Tim
 
Neither of those numbers are the correct numbers for the updated parts, per the Service Bulletin.

Here is a repost above of what to check before you order anything.

First thing to do is check the lettering on the SE valve.

The old SE valve lettering started with CL followed by three letters or numbers. If it starts with HG, then it has been updated.

Also on the carburetor bowl on the top carburetor, there is a number (jet size) engraved just above the drain nozzle. The old jet number was 80. The new one is 78.

So, if you have the old parts, these are what need to be ordered.
16023-ZW4-F01 SE Thermal Valve Assy
16023-ZW4-F01 Float Chamber Set (includes a new o ring)

The part numbers you found on boats.net are the old parts.

Check the lettering on the SE valve and the jet size on the bowl.

Mike
 
I did not reply about the idle mixture or your optimax comment.

I usually leave the idle mixture screws alone, if I am reasonably sure that they they have not been changed from the factory.

To be sure the passages are clear, you take the straw on a can of brakleen or similar solvent and put the straw up into the hole at the top of the venturi where the jet set (long skinney tube) goes. Put your finger over the air jet hole on the front of the carburetor, then position the carburetor so you can see the small pin holes at the rear of the top of the venturi. When you blast the fluid, it should shoot out of all of those holes. They are the holes where the engine gets its fuel for idle and transition.

Then also stick the straw in the air jet hole on the front of the carb and the fluid should also shoot out of the holes.

That will tell you that the idle passage is clear.

As for the opti squeeze bulb......fuel injected motors have vapor separators, which are a reservoir for the fuel and has a high pressure pump either in it or adjacent to it. That usually stays full all the time, unless you drain them....which should be done when you put the motor away for storage. Then you have to pump to bulb to fill it back up....unless the motor has its own electric lift pump, like a lot of the new mercurys.

It is possible that your bulb may be faulty and allowing fuel to flow back into the tank. Most builtin tanks have antiphon valves that minimize any backwards flow. As ShantyBay Tim suggested, squeeze your fuel bulb with it in the vertical position (arrow pointing up) and ideally, position the bulb when the motor is in use in the same vertical position.....or at least let it lay down horizontally. Positioning it with the arrow down will work, but it not optimal for the check valves inside the bulb....and could cause running issues.

Mike
 
Thanks guys for the tips.

Regarding the lettering on my carb - both the SE valve and the bowl have the old letters/80 - which are covered by SB59 - so the previous owner never had the work done to replace them. I've contacted my local Honda Marine service firm about possibly getting the parts from them, and if it would be covered by the warranty. Don't think it is, but they said they would call Honda and see if they would cover it. Otherwise I will order the new parts and replace them.

When I cleaned the carbs last week, I did what you described above about blowing through all the small orifices and passageways; things appeared to come clean and open; lots of spray coming from the tiny holes in the valve body.

Will try the vertical bulb operation to see if it helps. Also, I will find and clean the antiphon valve at the builtin fuel tank. When I bought the boat in June, I emptied the tank and flushed it out, cleaned the suction strainer, but did not take apart the antiphon valve.

More info to follow.

Thanks

Don
 
hondadude - interesting thing about the SE valve part number - on Honda Marine's own website, they list the wrong part numbers for the BF50A6 motor.
 
Regarding the antiphon valve at the builtin fuel tank - mine is mounted horizontally. Would this make a difference? Seems like it should have been vertical.
 
The parts sites list the correct numbers for the standard operation of the motor. The Service Bulletin only addresses those that have trouble starting. If a motor came in and it was starting fine for a customer, we would not change it out. This was only done during the warranty period. You warranty ran out in 2011, so it is very unlikely that Honda will cover anything, being that far out of warranty.
The logical response would be.....it has been working fine all this time, then something else is affecting the start up.

These parts are not part of a running change, like many other parts on various Hondas. I think, it might be because they were anticipating the change to fuel injection in 2008. Just a guess.

I have not seen a built in tank that the antisyphon valve was other than horizontal. If yours is in question, it is best to just change it out. That checkball is spring loaded so position is not as important and the squeeze ball, whose check balls are positioned by gravity and flow.

Mike
 
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