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honda bf15 cold start problems

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gpbrus01

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i had the carb cleaned in mid november. the first day of duck season, it started--temperature was in the 50s. The next day, it was colder, 30s, and it didnt start. Since then i have tried it and had the same results.
any ideas??:confused:
 
How long has the fuel been sitting around? Many areas of the country use different formulas in the summer than in the winter because of volatility. Try with fresh gas if you haven't already before you do anything else.

If you do re-post, list your model, year and serial number or what type choke you have, manual or electric, remote or tiller control and if it is pull or electric start. This might help someone here get you a better diagnosis.

Please do yourself a favor and DO NOT use ether starting spray. I will damage your engine.
 
its a 2006 bf15--electric start, auto choke, tiller control. I have always had fresh gas when I tried to start it.
Its weird because it started on one day when it was like 50 or 60 degrees but the very next day it was in the 30s and it wouldn't start.
 
Take cover off.------------------While cranking block airflow going into carburetor ( fingers / glove / whatever )-----------------This is the " super choke mode "-------------see if it helps in cold starting.
 
The auto choke defaults to "full on enrichment" at start up so I wouldn't suspect it as the problem. racerone's idea might work to get her going in a pinch but it should still start without doing all that with the temp still above zero. The fact that "in the 30's" causes a problem suggests, at least to me, that there may be a water issue with your fuel.

All fuel contains SOME water. It can separate and accumulate in various places in your system like low bends in fuel lines and the carburetor float chamber. The fuel might flow past a small amount of water "pooling" up when the weather is warmer but when the temperature approaches freezing, then the water molecules begin to expand (unique only to water) and take up more space offering increased resistance to flow.

But I believe your engine has a very "special" place for water to accumulate. Take a look at the link below of the motor's fuel system and note item #2. It is actually housed inside item #3 and will be attached to your engine oil dipstick tube. This "fuel chamber" acts as a water separator and needs to be taken off periodically and completely drained of all "fluid". These chambers have caused me many headaches on some 20 D's that I work on even when the weather is hot because they will eventually fill with, and retain, water. You won't notice, in hot weather, until it is pretty full of water because the fuel actually flows right past if there is room. In cold weather that might not be the case.

http://www.boats.net/parts/search/H..., JPN, VIN# BALJ-1300001/FUEL PUMP/parts.html

Pull that thing off and shake out all of the liquid inside and see if your motor doesn't start and run more easily. If so, good. But, you will then know that, along with removing all fuel from the carburetor float chamber after each use (my STRONG recommendation is to use the drain screw provided), you need to pull that chamber down and shake it out after about every 30 gallons of fuel. Possibly more often in cold conditions. Hope this helps and good luck.
 
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That is a very good point twin 150! One way to increase enrichment at start up is to work the throttle which in turn will inject raw gas into the carburetor bore via the accelerator pump. That is if you are getting raw gas and not water.

It is still my opinion though that, with a properly operating carb, good fuel delivery system, adequate compression, spark and vacuum, this engine should start in freezing temperatures without a bunch of gymnastics.

In addition, if you were to take the carburetor off of your engine and work the accelerator pump 7 times, you would probably be surprised at the amount of raw gas that you are dumping, in liquid form, into your cylinders. Repeatedly doing this will be detrimental to the life of the engine in that it tends to wash down the cylinder walls and pistons and allows gasoline to enter the crankcase and contaminate your oil.

But, then, I guess I'm arguing with success and that is something I probably shouldn't do. If it works for you, in the conditions that you operate in, then it works and that's pretty much that.

Regards,
jimmyd
 
I usually did this in the am when I launched the boat and let it run for 10 min. That was all I needed pretty much all day. In my opinion, that enrichment circuit doesn't last long enough. I could hear the system going from enrichment to normal and within a second or two, it would idle down and stall. It seemed like the over-abundance of fuel made that cycle last longer and then would stay running. The RPM's when warm were perfect too. So it wasn't that the RPM's were too slow either... By the way, I later switched to a 70 (or 72)* celcius thermo and pretty much eliminated my making oil issue. Going from the 60 to 70* C thermo really helped the overall running of the motor. Background--our ocean and river temps can hover around 45-50*farenheit. Also, we would troll DARN slow.

I can see your point about cylinder washdown being bad...
 
Yeah, can see where the enrichment cycle time might be a bit short for some lower temps but gpbrus01 says his engine won't start at all.

And, I can't figure out why in the world there is even a 140 degree thermostat available, period. Your switch to a 72C was a wise choice and THAT will probably do more good for making your engine live a long life than worrying about a few squirts of fuel. I'm just glad that you don't mention using ether on a cold start.
jimmyd
 
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