2001 Honda 9.9 HP Four Stroke ... stalling

[solracmd]

Trying to help neighbor with his stalling issue. I am new to forum but, have had great success with input and feedback. Thanks everyone in advance. Boat/Engine is used in fresh water and well kept. It starts up easy and runs well for a while at low idle (while trolling/fishing). Then, little by little the idle slows down and engine cuts off. Recently he ran the engine hard (as well as, used injector cleaner) at high throttle to see if there was something that needed to be loosened up. I am awaiting to hear if that improved the condition at all. Any thoughts on what we should be focusing on?

 

[solracmd]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Still looking for feedback ... Anyone pls?

 

[rsnyder518]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Ok, I'll jump in and see if we can get this thread rolling. A few questions to start:

1. You said when trolling it gradually dies off, but then said he ran it hard to try and clear out anything. It sounds like the problem only occurs after idiling/trolling for awhile, but not when operating at higher RPM's. Is that correct?

2. How long after starting does the idle speed start to decrease?

3. How long until it stalls?

4. After it stalls, does it restart easily? Does he need to squeeze the primer bulb to restart it?

I'm not any sort of mechanic but I am a little bit mechanically inclined. My first instinct says it might be a fuel delivery problem. But maybe the answers to the questions above can help point to something more specific? I don't want to start advising you to throw parts at it to see what works because that's an expensive way to fix anything! (Although I've been guilty of it from time to time!)

(Edit for spelling)

 

[solracmd]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Thanks for replying ... here are some answers to your questions :

(1) correct, occurs at low RPMs
(2) starts to decrease within 3 to 5 mins
(3) stalls within 5 to 8 mins
(4) restarts very easily, no need to squeeze bulb.

PS Since running it hard it appears to have cleared up a bit... just tryin to learn about what we should keep an eye out for

 

[jjohnson120]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Just a thought, but is the fuel tank vented? If not it may be building up pressure and vapor locking it. I've had something similar happen on mine, but it stemmed from the gas cap vent being closed instead of open.

 

[Davem3]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

could be carbon build up as well, or a dirty carb????? try running sea foam through it and see if it helps ?????

 

[rsnyder518]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Glad that it seems to have improved a bit after running it a little hard. At first I was thinking that maybe it was a fuel pump issue, but based on the new information that you provided I tend not to think so.

At this point I'm thinking that the carb may simply need a good cleaning. I know of people that have had success with Sea Foam as Davem3 suggested and it can't hurt to try. But if that doesn't work then pulling the carb apart for a good soak in some carb cleaner may clear up the problem.

Hope this helps!

 

[jjohnson120]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

If you conclude that it is the carbs, the only way to get it 100% is to take them apart and clean them. In some instances you may actually have to replace the needles. I ended up having to do this cause of old gas that sat in my carbs from the previous owner, and since then it hasn't had a lick of issues. Not matter how much Seafoam I ran through mine, it just never fully cleared it up, and honestly I wasted more time trying to do a quick fix than just taking the carbs apart.

 

[solracmd]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

Thank you all for the feedback ..... I will be following up with my neighbor this week

 

[stepphen]

Re: 2001 Honda 9.9 HP Four Stroke ... stalling

I have had numerous small OB's that do the same thing.


If the engine at slow speed is located in a outboard motor well like on some sailboats and the exhaust fumes rise up into the housing and into the carb. That will foul the plugs. usually it won't start again soon after this occurs but will a little later.. Try running the engine with a clear air supply. If you get an old vacuum cleaner hose and tape it to the carb intake . Place the other end of the hose in clear air. good luck. If you want to see what exhaust does to an engine just place the open end near the engine exhause fumes and watch the engine stall.

 

[sdanville]

No Title

Okay, here is how I fixed my Honda BF8 with the same problems. I took the carb off and cleaned it. but not good enough apparently as it still needed starting fluid.
I launched it in the river with a fresh tank of gas two gallons and 8 oz of marvel oil in it. I started it with the starting fluid.
I should add, I left the air breather cover off as well as the hood . then I used up my half can of carb cleaner spraying in the carb at various engine speeds.
after a 90 minute run, she would idle and not stall. Happy Days. Worked just as I hoped. cleaned out those vapor holes by running it.