BF99 runs couple minutes dies

"This has been a worsening pro

"This has been a worsening problem and yesterday became unacceptable. Had to get a tow back to the mooring. It starts acceptably, then runs for a period and then dies, like it is out of fuel. Happens both at idle and at moderate throttle. It may or not restart right away, but will quickly die. Sometimes I have to let it sit for awhile, which can get hairy in a busy harbor with a very strong tidal current. Same on both fuel tanks. Could be the fuel line but I think not. More likely the carb. This is an electric start and has an electric choke which I hate. Or it could be ignition.

I need things to try on the mooring. Boat is a 1962 Rhodes design sailboat, the engine is in a well and very difficult to remove. The nearest Honda place is out of the harbor into the ocean and back into another harbor. Or I have the boat hauled.

Thanks!"

"Can you remove the engine cov

"Can you remove the engine cover and run it in the well?

If this causes the problem to go away, you could look into an exhaust or crankcase breather leak contaminating the air under the cover.

Will the primer bulb keep it running? If so, then fuel pump could be the problem."

"You said it happened at low a

"You said it happened at low and moderate speeds. What about full throttle?

I agree with pilotart. But if those items do not do the trick, pull the connector off of the overheat sensor. It is located on the side of the head between the spark plugs. If the motor overheats, the sensor shuts the motor down. If the motors starts right back up after the sensor is disconnected, it is probably an overheat. (bad impeller or stuck thermostat)

Do not continue to run the motor with a disconnected sensor!"

"RE: "1962 Rhodes design s

"RE: "1962 Rhodes design sailboat, the engine is in a well "

It is not uncommon for sailboats with this type of setup to have this problem. Usually caused by lack of air to the engine or exhaust contamination of the air in the well.

The quick diagnostic for this is to see if it runs OK with the hatch cover open."

"Thanks guys. I have been runn

"Thanks guys. I have been running it for testing with the cover off so I think the air it is breathing is clean. I do have a question about the primer bulb and I was thinking of trying to pump while it was running to see if that helped but didn't get to that. How tight should it get? On this engine it never changes. Always pretty squishy. Repair shop it was at once before said it was fine.

BTW, one of the previous haulings for repairs was to replace the carb. Honda did it under warranty. It would not start if it had set up two weeks or more. The engine was only a year old at the time. I so do wish I had a manual choke.

There is a strong stream from the P-tube so I would say the impeller is good. But I guess it could still be a overheat problem. It would be nice to have warning light on that."

"Being sqishy is probably okun

"Being sqishy is probably okunless it is imploated, but like pilotart said, there could be an issue with the fuel pump. Continue to squeeze the bulb (you will be acting as the fuel pump). If motor continues to run it could be fuel pump or it could be a bad check valve in fuel bulb. Also be sure that arrow on the pump points up or horizontal as the motor is running. If you have a buddy with a honda, borrow his fuel line and bulb and see what happens.

I guess Honda decided is is better just to shut the motor down than to give the customer an option (just a overheat warning) if it overheats. I can see both arguments.
Pulling the connector off the overheat sensor will only take a couple of seconds and can quickly tell you about overheat.

The carb on this motor is quite intrique inside. A lot of passages inside and even in the fuel bowl. A good fuel treatment is a must to keep the passages clean. Even better to run the carb out of fuel and drain the carb when it is going to sit. It seems like carbs are a problem on sailboats due to them sitting a lot.

Unfortunately, to change it to a manual enrichener, you would have to change the whole carburator and install a manual choke cable for about $185 for the parts. The only difference is you are controlling the enrichment manually. Enfortunately, warranty may be an issue on a forward going basis, depending on your relationship with the dealer. Officially, it would be tampering with the epa specs..."

"I know you probably checked t

"I know you probably checked this already, but on the off chance that you didn't...Are the vents on the tank(s) open and clear?"

"Review of what I have so far,

"Review of what I have so far, and one more question:

I have been testing it with the hatch cover open, and the engine cover off. No effect.

I have tried both fuel tanks, but same line and bulb. I have checked the tank vents and believe them to be open but am going to go over that again.

I will try pumping it with the bulb and pulling the overheat sensor after it shuts down to see if that restores life to it.

Now, the question. This engine did have to set up for four years through no fault of its own. It was winterized when it was last used. And carb run dry, I do that with all of my engines. And the fuel is new, bought just before launch, and has Stabil in it. And that Ethanol stuff all our gas around here has. But still I am suspicious that it could be the passages in that intricate carb.

Is there something that I could try running through it out there on the mooring to help clear it out?

One more, what about checking block temp with a IR gun? I have one, but I need to know some reference as to what is normal."

"Thermostat opens at 140 deg F

"Thermostat opens at 140 deg F and is fully open at 158 deg F. I usually shoot at the top of the thermostat housing. It is on the port side of the engine, mid way back about the same level as the top spark plug. Look for a flat black plasic cover, held by two 10mm bolt. It is not round but about 2 inches in diameter. If the problem is an over heat (proven by temperature, remove the thermostat (only two bolts), then give it a try. The motor may not idle well since it will never come up to temperature, but it is ok for a test and will not hurt the engine to do it for a short time.

Hopefully, you also drained the carburator when you stored it. If not, there is probably residue in carb bowl. There is an accelerator pump inside the bowl also, and it can be very easily corroded and stuck especially if there was water in the fuel.

I do not know of any miracle solution for the carb that will work in your situation. I have had limited success in that area. Anything that you spray into it, justs goes directly into the intake bypassing any of the jets, etc in the carb. It is generally, just as easy to just remove and clean the carburator.

As far a checking the venting of the tanks...just loosen or remove the fill cap for the test.

If overheating is not the problem, then take some starting fluid (bought at any auto parts outlet), and when the engine starts to fail, shoot a very very short burst into the black plastic (silencer cover) intake of the carburator. You will probably need to use the little straw that comes with it to get it into the passage. There is no direct shot. If the motor picks up, it is probably the carb. If you shoot too much, the engine may die. Try this a few times before moving on to something else."

"Worked on it a while yesterda

"Worked on it a while yesterday. Ruled out over heating right away, It stalled repeatedly in the first minute. Had to advance the throttle to get it to start and stay running. Ran it at fast idle for 15 mins, then cut back to low idle and it stalled, Restarted and it ran at low idle, but very rough. Tried pumping primer bulb and that seemed to help, but not for sure. Playing with the throttle did. When it would start to stall I could gun it a bit and it would pick back up, and at times it would accelerate to moderately good speed and run smooth, then drop back down and run run rough. Engine temp measured with an IR gun on the thermostat is 137 degrees. Then for lack of anything else to try, I disconnected the fuel line. It was running at slow idle and it settled down and ran smooth for five minutes before stalling! I reconnected the fuel line and this time the primer bulb tightened up. First time it has ever done that. Restarted and it was running rough again, but after a bit it was better and I disconnected it again. This time it actually would continue to run a dead slow, something it would not do previously. Reconnected, bulb pumps up hard, still somewhat rough at dead slow but better. Pulled it again and let it run out a very fast idle in three minutes. Not perfect but much better. I almost trust it. The was about 1 1/2 hrs of running, maybe one gal of fuel.

My son is a bartender at a dockside restaurant and one of his patrons said he had exactly the same problem, it was water in the carb and he used Star Brite to clean it out. I have Stabil in the fuel but not the marine variety. The manager of the boat yard where I go now thinks it might be the fuel filter but I can't get one till next week. So is one product better than the other for cleaning up tank, line and carb? Taking the carb off for cleaning is impossible with out hauling the boat."

"Good news on not overheating.

"Good news on not overheating.

I assune you have a built in tank. If any of your buddies have a portable tank to lend you, flush the fuel system. There is a drain screw on the carb and there should be a hose from the drain to an outlet next to where the water tell tail comes out. If you are good, you should be able to catch most of it in a glass jar. Then you will see if you have water in the fuel for sure, plus you can continue to flush with clean fuel.

It could be fuel filter, but you said it runs ok at higher speeds. That is where you would normally see a clogged filter affect you.
If you haven't changed it for a while, it would probably be good to do so anyway.

It almost sounds like the motor is running rich. I am thinking that because, you said that it runs ok at a fast speed, it is using the fuel you are giving it. At slow speeds, it runs rough, which could be too much fuel...but smooths out when you remove the fuel line which leans out how much fuel it is getting. A couple of things could do it. 1..A stuck float needle (which could have been the reason the bulb would not get hard when you squeezed it. The needle may have become unstuck but not quite clean. 2..the starter enrichener may not operating properly (it is open at cold start to allow extra fuel into the carb, then as it heats up, closes down to turn off the extra fuel). If it is not cloaing down, the motor will get too much fuel (too rich) at idle. Make sure the wires coming from it are connected. If you have a volt meter, make sure that it is getting 12v when the engine is running. Even if it is, it could be stuck or faulty.

You asked about products for water in fuel...maybe someone else may have some thoughts on that. We use water separating fuel filters, pump the tank (or at least partially), and use Sea Foam. Sea Foam has some properties to help with water. We like it mostly because it can help clean your potentially stuck float and clean the passages as long as there is some flow internally. It works as a stabilizer too. Snake Oil!! A shock treatment of that sitting in the carb for a week may help."

"I'm having the same probl

"I'm having the same problem with my 2001 8hp. I just had the engine serviced this week and just took it out for the first time in a month, but it started spitting and sputtering, then it died. It did the same thing before I had it serviced. If it sits for a few days it starts right up on one pull. I'll be following this post to see David's progress."

"Thanks, Mike. Your posts are

"Thanks, Mike. Your posts are helping me get a handle on this. BTW, this is a 9.9, 4 stroke, electric start with external fuel tanks. Has 30 hours on it at the most.

If the needle float was not seating wouldn't there be some fuel leakage? I was out there for an hour and half in very calm (and hot conditions) and kept an eye on the water around the stern. I did not see any spill. I have two other engines that do have that problem, the 2 hp Evenrude on the dingy that I only open the fuel valve when I am ready to start, and my Coleman generator that was spewing gasoline out earlier this week. I had external combustion engines. Waiting on carb kit for that one.

Were is that starter enricher with the wires going to it? I want to check that. Remember that this has electric enrichment, and the carb had to be replaced by Honda about 15 hours ago."

"Yes, you are probably right o

"Yes, you are probably right on the stuck needle. Most people do not notice the fuel leaking. I can not explain the fuel bulb issue unless it had a bad check valve inside the bulb. Always squeeze it with the arrow pointing up.

The enrichener is on top of the carburator. It is off white in color and is about an 1 inch in diameter. It is held on with one screw and has
wires coming out of it.
As I said, check to be sure the wires are connected...they generally cross over the top of the engine.

You can remove it from the carburator and reseat it. It you do, be careful not to drop the screw into the water. I usually do...
Before you reseat it, it would be worthwhile to shoot some brake cleaner (using the straw that comes with the can) down the vertical passage. If you have a small can of compressed air, a short shot down the same passage could help clear it.

If there still is no change...check the idle air mixture screw on the side of the carburator. It has a limiter cap, so you can only turn it about a half of a turn. Try moving its position and see if anything improves with the idle.

If they replaced the entire carburator with a new one, it comes with a new enrichener.

Is it possible that the idle is not set high enough? That adjustment is an idle stop screw on top of the carburator. You can access it with a long skinner screwdriver from the rear of the motor. Only turn it a very small amount. Clockwise increases idle...counter clockwise decreases idle.

I am assuming that the motor ran fine when you had the carb replaced. Unfortunately, it does not take long for fuel to turn into goo if the motor is not used a lot. Pretty typical on sailboats. Sea Foam, Pri-G, Quickleen, etc may help."

"It sounds like I am putting y

"It sounds like I am putting you through a lot of steps. If it were in the shop...after making the adjustments I just mentioned, I would pull the carb, clean it and be done with..."

"Thanks, Mike. I really do app

"Thanks, Mike. I really do appreciate your help. And if it were out of the water it would go straight to the shop. But I am an engineer and my life is troubleshooting, so with your help and the help of others I am going to do everything I can to save this sailing season. We only have about a month left."

"I'm embarrassed to say, t

"I'm embarrassed to say, the first thing that I should have asked you to check was the oil level. It should be a little below the top mark on the dipstick. The motor will not run worth a darn if there is too much oil. It is always the first thing I check and fixes the problem maybe 10% of the time."

"Actually, if the float valve

"Actually, if the float valve does not seal, it does not leak anywhere you will see...the leak will be into the carb throat causing it to run rich (and lousy at low speeds). If disconnecting the fuel line fixes your problem, 99.5% probability is that the fuel float valve is either not seating and sealing, or the float level setting is too high."

"Mike and Robert, those are bo

"Mike and Robert, those are both excellent points. I did check the oil, it was halfway between full and add. Pretty difficult to do in bright sunshine with clean oil, but I had my wife look too. I added a bit, but not too much. And I will file that caution away.

I think the theory that the float valve is not sealing is sounding like the most likely cause. And it helps to know that it would not leak out of the carb. That explains both why it runs fine when the fuel line is pulled and now that it getting a bit cleaned up the primer bulb will harden up. Something to push against, not just pumping gasoline into the throat.

I hope this helps Jan out."

I'm basically having the s

I'm basically having the same problem. Does this mean that I just need to take the carb apart and clean it to keep the float valve from sticking?

"Jan, taking the carb apart fo

"Jan, taking the carb apart for me means pulling the engine from the well, and that really means hauling the boat. So what I have done, and it seems to be successful is to use lots of Marine Stabil and repeatedly pull the gas line and let it run dry. I think 'cause the float is hanging down the crumbs are getting pulled through and getting cleared out. And now I have and emergency procedure; I can pull the gas line and I've got 3-5 mins run time before it runs out.

I was not able to continue work on this weekend, too many thunderstorms and Bill passing by. But I did resolved the same problem on my generator at the house. Every time it flooded I took the bowl off and dumped it into a clean cat food can. They have a white coating and make it easy to spot crud. After about three times it was all gone and the generator was running fine."

"RE:"But I am an engineer

"RE:"But I am an engineer and my life is troubleshooting,"

So am I... or more accurately... "was an engineer" (until they exported my job overseas).
Then again my family says no matter what I do I AM an engineer, regardless of what I'm getting paid to do.

That said. If you can get the cover off the motor while its in the well, you very well may be able to get the carb off the engine...

Also... Re: "pulling the fuel line" I do that every time I hit the channel marker outside my marina. My BF75 happily runs more than long enough to dock my Bristol 22 before stalling out."

"I'll just take the motor

"I'll just take the motor off. I'd rather do that than loose parts in the drink.

Thanks,

Jay"

"Well, after a two week hiatus

"Well, after a two week hiatus due to tropical storms and travel I got back to the boat yesterday. It took 15 mins to get the engine started, and that was archived by playing with the throttle until it started running at a very fast idle. I let it run like that for while to recharge the battery.

Over the next 2 hrs I got about 1.5 hrs running time. I added a double dose of Marine Stabil. I ran it dry many times, everything I could think of but it still would not stay running at a slow idle, and if I left it with the throttle advanced it would wander up and down in speed, from a stumbling low idle to a very fast idle. (Wish I had a tac) At one point I let it sit not running for a half hour while my wife and I had lunch, read, and avoided looking at the many sails out on the ocean.

I do not think flooding is the issue anymore. The primer bulb will pump up hard most of the time, and running without the gas line connected no longer improves things. Which probably means that the fuel filter is not the problem either.

Is there a petcock on this engine that I can reach and drain the carb? Will letting it sit for 24-48 hrs with the high concentration of Marine Stabil possibly help?

Its beginning to look like the end of the season for us."

"Dave,

I clean out the carb

"Dave,

I clean out the carb over the weekend and was still having the same problem. I thought it was the fuel pump but it was working just fine. I then discovered that my problem wasn't fuel. I took a look at the ignition coil and found some rust around the mounts. I removed the plug wires from the ignition coil and re-seated them to get a better contact. The motor started up on light pull and ran for 10 minutes until I throttled it up. It died. I checked the spark plugs for spark and I either got an intermittent spark (not the normal click,click, click, but a spark here and there) or no spark.

I tried re-seating the plug wire contacts to the ignition coil and got no spark. The spark plugs are brand new so I figured it has to be the ignition coil. I'm guessing water got into the area around the coil and shorted it out.

I ordered a new ignition coil from boats.net, for $65.00 plus s/h. This should fix my issue, if it doesn't well at least I have a new ignition coil.

Anyway Dave, long story short, your problem may be electrical and not fuel related. Check your ignition coil.

Jay"

"Dave,
If still sounds like a

"Dave,
If still sounds like a fuel issue.

The carb does have a drain. As you are looking at the carburator from the side of the engine, it is on the right side at the bottom. It is a standard screw that is black. You will need a long thin screwdriver and probably a flashlight to see it. Just back it out some. The fuel flows down a clear tube to the outlet right next to where you see the water piss out of the motor. Check the storage section of your owner's manual for a picture.

There is also a fuel baffle in most 9.9's that could retain water and debris no matter what additive you put in it. It is located below the carburator under the side cowling.

I have not had experience with Marine Stabil but I am not sure that any solution in a can is going to clean the passages enough in your carburator. It may help with the main jet, but there are several passages in the upper part of the carb that the solution can not get to. They have a lot to do with starting and idling.

Is there no way to get the carb off to clean it? If not, I think this is going to be a very frustrating battle.


If you think it is ignition, get a timimg light to watch the pulses as the motor is stopping. If they go away or are intermitant before the engine stops, it could be spark. IF the spark continues relatively evenly as the engine comes to a stop, it is probably not spark."

"Opps, my last post never made

"Opps, my last post never made it. I will check the ignition coil. There was a corrosion problem a while back due to the p-tube splattering on the hull but that has been corrected now.

I am tending to agree with you Mike, it is fuel related. Is that plastic drain tube the one that goes to the port right next to the p-tube port? No one has ever given me a good explanation of that.

Please tell me more about that fuel baffle. Is it a separate piece from the carb? How does it get cleaned.

I'm going to get back out there again this weekend, try a few more things but since it seems the engine is getting less reliable it may be time to pull the boat for the season. Groan. Only two sails."

"Yes, it is the one next to th

"Yes, it is the one next to the p tube. The fuel baffle is below the carburator under the side cowling. You may want to look down in that area to be sure the hoses are not kinked. There were some 9.9's that did not have a baffle. It is black, about 3 inches long and 2 inches in diameter."

"David,

FYI...I had a 20hp

"David,

FYI...I had a 20hp Honda in this week doing exactly what yours is doing. It was practically a brand new motor, but the idle jet had some debris in it. I checked the other passages and they were clear. Put it back together and the motor ran fine.

The passage in the idle jet is very small and the jet is about 2 inches long going from the bowl area to the top of the carburator. Therefore, most of the jet is above any solution in the bowl. Which means no solution in the carb can not even reach the blockage to dissolve it.

Sorry to be so pessimistic..."

"I fear you are correct, Mike.

"I fear you are correct, Mike. I went back this weekend. I could see the clear (amber now?) tube coming down from the carb, and with my finger I think I touched a screw, but without removing the lower shroud there is no way I can see to get a screw driver in there. Same for that fuel baffle. I can just make out something in the fuel line and touch it with one finger.

So I sighed and took a deep breath and call the haulers. They can fit me in on Wed and I called TowBoat to bring me over to the docks. Once it is back on the hard I can pull the engine and get the cover off.

Next year it will have an additional fuel filter in the gas tank line that I can see, and change."