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Honda 1996 5 hp 4stroke.

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Magaucher

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Can someone help me please. I recently bought a 1996 Honda 5 hp 4 stroke. It starts with no problem but as soon as the RPM slows down it stalls, low idle problem. I have cleaned the carburetor about 4 times but no luck. Is there something else other than the carburetor that can cause this problem.
Thank you so much for your help.
 
Welcome, when cleaning the carb are you dismantling it completely and making sure all the very tiny passages are clear?
 
I also took out the jet screw and the little hole was very clean and clear, I took out the little copper tub it was also clear and clean as well as the little holes on the side of the tub.
 
Can someone help me please. I recently bought a 1996 Honda 5 hp 4 stroke. It starts with no problem but as soon as the RPM slows down it stalls, low idle problem. I have cleaned the carburetor about 4 times but no luck. Is there something else other than the carburetor that can cause this problem.
Thank you so much for your help.
 
Look for a small passage adjacent to the air inlet of the carb. Usually above the top of the inlet. That should be the main air jet that helps pull fuel through the jets and send it to the orifices above the throttle plate. Spray liberal amounts of cleaner through that passage and also through the tiny orifices above the throttle plate. It sounds like you may still have some dirt in the idle circuit.

Good luck.
 
I have found that sometimes carb cleaner cannot clean all the small passages, especially if you have hard medium object stuck that the carb cleaner can't break down. I use a two stop process typically, 1. carb cleaner, 2. compressed air to finish off.

If none of those work, I say screw it and buy a new carb. Worst case is you keep the old one for parts. Being yours is a 1996 (22 years old) I would buy a new carb before they are discontinued for good measure. That motor will run forever with proper maintenance. I had a 1985 that ran like a swiss watch, I loved that motor, wish it was a twin cylinder to reduce some of the vibration of the single cylinder but it was an awesome reliable and well built motor.

https://www.boats.net/product/honda/16100-ZV1-A03?ref=e07c5d5563fe6abcd578412ea5e1b6fa8cbb20bf
 
Thank you for the info, I’ll try and clean it and I’ll also check out the cost of a new carb. I’ll keep you posted and thanks again.
 
Well I cleaned it out once again, every little hole with carb cleaner and I also cleaned it with WD40 and still no luck. I think I’ll order a new carb, it will set me back $255.00 plus tax, I hope that will work and Honda said they can still be ordered. Is it possible that something else can cause a low idle problem or is it just the carb that can cause that problem, I’m not a mecanic. Thank you once again.
 
When I use the carb cleaner or WD40 do I let it sit for hours it that stuff, I only let it sit for about 15 min.
Well I cleaned it out once again, every little hole with carb cleaner and I also cleaned it with WD40 and still no luck. I think I’ll order a new carb, it will set me back $255.00 plus tax, I hope that will work and Honda said they can still be ordered. Is it possible that something else can cause a low idle problem or is it just the carb that can cause that problem, I’m not a mecanic. Thank you once again.
 
Magaucher said:
When I use the carb cleaner or WD40 do I let it sit for hours it that stuff, I only let it sit for about 15 min.
Well I cleaned it out once again, every little hole with carb cleaner and I also cleaned it with WD40 and still no luck. I think I’ll order a new carb, it will set me back $255.00 plus tax, I hope that will work and Honda said they can still be ordered. Is it possible that something else can cause a low idle problem or is it just the carb that can cause that problem, I’m not a mecanic. Thank you once again.
Click to expand...

$255! That link I gave you above was for Pre 1998 at $155. Order it from www.boats.net like the link above if you are buying new. I have personally never heard of cleaning a carb with WD40, I would think that would leave oil deposits throughout causing more gunk to stick in the passages. Carb cleaner and compressed air is what I use.

Other things to check is if you have the idle screw set to low, that will cause it to stall out at the bottom of the throttle, start it and then turn the screw to the right on top of the carb till you find a sweet spot.

Have you check all your fuel connection? You may be sucking air or have a blockage in the pick up in the tank or in the line or a collapsed bulb. Things to check for this are:

1.) If the lines and bulb are more than 5 years old, buy new, they breakdown and cause running issues. They will degrade and break down from the inside out.
2.) Make sure all hose clamps are tight, not allowing the engine to suck air, which will cause running issues
3.) Check your spark, I don't think this is your issue as you said you can get it running.
 
wd 40 is not a carb cleaner go NAPA and buy 2+2 carb cleaner they sell it behind the couter you have to ask for it use rubber gloves when cleaning this is goo stuff.
 
Take carburetor apart .----Post pictures of the parts you have cleaned.----I am convinced that you have overlooked a passage way for idle fuel.----There is no way that I would buy a new carburetor for one of these motors.-----But what other trouble shooting has been done?----Not that it has anything to do with idle , but has the impeller been replaced ?
 
It’s been sitting in a barn for 10 years, it still looks extremely clean with just a few scratches on it. The water pump work fine, motor starts good just the slow idle giving the problem. Today again I soaked the carb with carb cleaner and it sat for 30 min, no luck still have tha problem.
 
I can see how frustrating this is for you. It still sounds like a poor fuel delivery issue. Have you verified the fuel tank is venting by running it with the fuel cap loose? Sometimes, in cases like this, that's all it is. The fuel tank isn't venting.

Have you taken the plug (item 8 in parts page link below) for the air bleed passage out and sprayed in there really well? The gas has to travel through the "junction" under that plug to get to the delivery orifices.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/5hp/bf5ak-la-pre-1997/carburetor

Other than the carb, the fuel pump diaphragm may have dried up badly during the 10 year storage. It could have gotten so brittle that it may have cracked. Have you tried pumping your primer bulb while trying to accelerate?

One other thing that I see with these is that the cam has a centrifugal weight with return spring. I don't know but I'm guessing that the weight is altering valve timing as the engine speed increases. If this is the case, if the weights rusted and got stuck during the long storage, it could adversely effect the engine accelerates. See page in link below.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/5hp/bf5ak-la-pre-1997/camshaft

Just some more ideas to consider.

Good luck
 
I’ll try a new gas tank, I did take out the #8 screw and #5 , took out #10 and 37 and sprayed in al, of them. The motor shows no signs of rust at all it has been very well greased. A cold start with the choke starts it with ease, motor runs fine and accelerates with no problems at all when you turn the tiller handle giving more gas, as long as I’m holding the tiller at a higher speed it will run without stalli, that said it seems to be getting gas into the carburetor with no problem, bit again I’m no mechanic. I’ll try the other gas tank and let you know, thank you again.
 
If it has been sitting for 10 years, I would at minimum do the following:

1. Replace internal and external fuel lines + bulb.
2. Inspect the tank replace if needed (inspect the pick up screen specifically)
3. Inspect the thermostat & replace seal
4. Replace the impeller if not the entire housing (pretty cheap), this should be done every few years depending on use. Its WAY over due and probably dry rotted. If it breaks apart you will have more work ahead of you trying to clear the blockages it creates.
5. Clean the carb or replace it
6. Replace the fuel diaphram


Do you not have access to compressed air or an air compressor with an air nozzle? Sometimes you need that air to extract what carb cleaner cannot disolve.


I would also swap out to a new plug and drain engine oil + replace and drain and replace the lower unit oil. Doing all those things on that motor will ensure reliable operation and should be part of your regular maintenance outside of replacing a carb or fuel diaphram.
 
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This has a dashpot. I don't know this engine but on carbureted auto engines dashpots are used to keep the engine from stalling during acceleration or to compensate for sudden added load like an a/c compressor coming on. Since outboards aren't air conditioned, I'm assuming it's there to prevent stalling during decell. Item 13 in link below.

https://www.boats.net/catalog/honda/outboard-by-hp-serial-range/5hp/bf5ah-la-pre-1997/carburetor

Looking at the dashpot in the parts blow-up, it has a check valve (item 24) in the line that leads to the intake "joint"( item 18) which connects it to access intake manifold vacuum.

Since you say the engine runs well except when dropping back to idle, I'm wondering if the dashpot or it's connecting tube might be malfunctioning. I wish I could tell you how to test it properly but I don't have that info. All I can say for sure is to make sure there are no engine vacuum leaks associated with the tubing or the joint (connector) and, possibly, take the check valve off and verify that it only allows flow in one direction.

Just more ideas.

Good luck.
 
Wow lots to lean in a little motor, I’ll have a look at that today and see if there is something I can find. I hate to bring it to a marine shop as I don’t know if I’d be charged for pats I don’t need, not to say they all do that but I was told some do.
But what your saying may be the problem, thank you again. I’ll let you know if I find something, wish I knew how to check a dashpot.
 
Dashpots are just diaphragm chambers that are vacuum and spring activated. Think of the vacuum from the engine pulling on the diaphragm inside and the spring inside pushing back. So, it can only fail in two ways:
Either the diaphragm develops a leak due to a tear or crack or the spring inside breaks. Many of them have a very small vent hole in the can opposite where the vacuum enters. We used to check the integrity of the diaphragm by blowing cigarette smoke into the vacuum side and see if any came out of the vent hole. If so, bad diaphragm.
If the spring inside is broken it will rattle when you shake the can.

The only other thing I can offer is to say that the intake experiences the highest vacuum during sudden closure of the throttle. The engine is at a high rpm when the throttle plate goes closed and the fast moving piston trys to pull air in.

I don't know how the dashpot interacts during this scenario but I do have a guess. But, it's only a guess and trying to explain it might only serve to confuse you. I would rather you look it over for yourself first. Then, if you want my "version", which could be complete poppycock, I will happily share it with you.
 
Essentially the dashpot prevents the throttle plate from closing suddenly.----Makes for a " smooth slowdown " you might say.
 
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