new Honda O/B 9.9 hp stalling- too lean ?

[tasdevil]

I bought a " relatively " new Honda 2005 9.9 with electric start . It starts and idles quite well , but when I increase power to leave the Marina it sometimes quits.

I have had it overhauled and serviced and the O/B mechanic says the problem is that it is running too lean. He says that Honda set them that way to reduce emissions - and the adjustment screw is installed in a way that it can not be adjusted further ! He says that it is a fairly common problem and that there is a way to fix it - but he doesn't know how it's done !

Has anybody else had this problem ? - and do they know the solution ?..Rob

 

[Ross]

Talking through my hat here about auto carbs but a mechanic told me that some adjustment screws were capped with plugs that could be drilled out and access gained to the adjustments. I have no idea if this is the case but someone, somewhere had to set those adjustments initially.

 

[Steve Dion]

Why don't you contact Honda America. You are surely not the only one that has had this problem. Make sure they understand that this is a "safety hazard".

 

[Willjacocks]

We have this problem with an older model 9.9 HP 4 stroke Honda outboard. It never did that before I put it on my sailboat. (we have a flat bottom skiff for running around and fishing) My guess that the gas is old, but have been using my Nissan 3.5 lately so haven't had to do anything with the Honda yet. One of these days....

 

[gfrazzle]

1. Clean the carb

2. Drain the tank and replace with fresh fuel

3. Get a new mechanic

I bought a " relatively " new Honda 2005 9.9 with electric start . It starts and idles quite well , but when I increase power to leave the Marina it sometimes quits.

I have had it overhauled and serviced and the O/B mechanic says the problem is that it is running too lean. He says that Honda set them that way to reduce emissions - and the adjustment screw is installed in a way that it can not be adjusted further ! He says that it is a fairly common problem and that there is a way to fix it - but he doesn't know how it's done !

Has anybody else had this problem ? - and do they know the solution ?..Rob

 

[Don12364]

When an engine is idling the throttle butterfly is all but shut off and the idling jet is sized so that the vacuum behind the butterfly is just sufficient to draw enough fuel to keep the engine idling.
As soon as someone puts the engine into gear and opens the throttle, even only slightly, then, before the engine can accelerate and begin to draw fuel by increased airflow through the carburettor main venturi and over the main jet, this vacuum immediately reduces and so the engine starves of fuel.
The engine would stop if it were not for the transfer bleed hole(s). Many small engines with Solex type carbs have this transfer jet or bleed hole drilled into the carb casting and it is often an extremely small hole and prone to blocking or gumming up - particularly in two strokes.
Remember the designer knew of this starvation difficulty and will have made provision for it.
In some instances this transfer is two drillings about 1mm in diameter (.040") connecting up with the fuel and one each side of the butterfly.
The solution is to make sure that every hole, even the tiniest, is clear by soaking with a solvent and blowing out with an air line. Not by poking with a wire though, in extremis??

See:-
http://en.wikipedia.org/wiki/Carburetor
Off-idle circuit
As the throttle is opened up slightly from the fully closed position, the throttle plate uncovers additional fuel delivery holes behind the throttle plate where there is a low pressure area created by the throttle plate blocking air flow; these allow more fuel to flow as well as compensating for the reduced vacuum that occurs when the throttle is opened, thus smoothing the transition to metering fuel flow through the regular open throttle circuit.

 

[Honeyman]

Ethanol in the gas supply is beginning to cause more and more problems. It really cuts down the "shelf life" of stored gas. Keep this in mind as well.

 

[kloudie1]

Honda.. common problem is an air leak at the tank or moror disconnect.. Test by holding hand pressure on the bulb while advancing throttle.. Could be bad check valves in the fuel pump too.. but if hand pressure on the bulb solves the problem, it is not in the carb. Good luck

 

[RichBone]

Problems with Hondas aren't new. A friend of mine had a similar problem with his 7 1/2 hp twenty years ago. Motor started and idled great, but as soon as he accelerated it would die. He tried everything, never did get it running right.
He finally traded it in for a two stroke.

Rich

 

[druid]

I had exactly the same problem with my 3006 Mercatshu 9.9 4-stroke, with the same response from two different dealers. One even said "that's the way they're SUPPOSED to run". Apparently it's even illegal to mess with the mixture due to the Environmental Police.

I think the solution is to find a mechanic willing to ignore the EP and set the jets right.

druid

 

[Steve Dion]

Recent info about ethanol fuel

http://www.seaworthy-digital.com/seaworthy/201004#pg9

 

[Ross]

Recent info about ethanol fuel

http://www.seaworthy-digital.com/seaworthy/201004#pg9

Finally a scientific explanation for a whole bunch of opinion.

 

[Quoddy]

Honda 2005 9.9

We have a Honda 9.9 2005.Stalled once at idle but restarted and ran fine. We have not had your problem, so I suspect it is not a problem were you have to defeat factory adjustments. Dirt and gum buildup, which has been suggested, is probably the cause. I read that this Honda could be very sensitive to this type of buildup. We have always used fresh high-test gas which is supposed to have a higher percentage of cleaners. We run plenty of stabilizer in the fall, then run it dry and finally drain the carb.So far so good.
One more thing, I found the gas tank to fuel line O ring decaying after only 5 years, so the air leak idea should be checked.