I have 2 new HondaBF15's that basicly do the same thing, after the
proper break-in i do a high speed run down the lake and start troll at
low speed ,after around 30 to 40 minutes they have a misfire and or
will stall, one will do this approx. every 3 to 5 minutes and the other
alot less frequently but will still have this misfire and or stall, the
latter engine does run a little rough until you up the rpm's at
start-up. This misfire (could also be termed sputter,flutter, bad
shake, whatever term you want to use) can be seen at dealers tank so
that rules out my KNOWN good gas because i tried different stations,
different grades, isopropal, that chevron techron stuff, and sea foam
sprayed thru carbs.The first motor had the plugs pulled at dealer after
idling in tank for about 40 minutes these were as follows one tan and
one a little darker, tan to black , just for kicks i changed both plugs
, problem still there.The second motor that does this less frequenty
the plugs are between a dark tan and black but definately not
fouled.Idle speed was checked and set per specks.I'm told by Dealers
that that they sell tons of these with no problems, I troll for hours
at a time, is a constant bad misfire and stalling normal (they start
right back up ? I was only looking for the same performance i got from
14 years of trolling with a Yamaha 15 2 stroke, it never skipped a beat
and only changed the plugs once a year. Anyone else have this problem
or symptom.

On 31 May 2006 05:56:05 -0700, "hondo" wrote:
after the
proper break-in

"Break in"?? Do you mean warm up?

after around 30 to 40 minutes they have a misfire and or
will stall, one will do this approx. every 3 to 5 minutes
snip
(could also be termed sputter,flutter, bad
shake, whatever term you want to use)
snip
(they start right back up ?
snip
Anyone else have this problem
or symptom.

I bought a new BF20, basically same engine as yours. It apparently
came out of the crate with a bad impeller. Or at least disintegrated
within the first couple of hours of operation. I had similar symptoms.
Motor cranked up and ran fine for a few minutes then went into a
coughing sputtering fit and eventually died. Then it would crank right
back up, no prob, and run fine for a few more minutes, then repeat the
process.
I thought it was bad gas or trash in the carb. But it turned out to be
that bad water pump impeller. Seems those little motors have a
computer that senses the cooling water pressure or temp or something
and when it's not right, the motor goes into this coughing sputtering
fit to save itself from overheating. -shrug- who knew?
Anyhow, a new impeller resolved the problem (and no, the warranty
didn't cover it). YMMV.

Rick

hondo wrote:
I have 2 new HondaBF15's that basicly do the same thing, after the
proper break-in i do a high speed run down the lake and start troll at
low speed ,after around 30 to 40 minutes they have a misfire and or
will stall, one will do this approx. every 3 to 5 minutes and the other
alot less frequently but will still have this misfire and or stall, the
latter engine does run a little rough until you up the rpm's at
start-up. This misfire (could also be termed sputter,flutter, bad
shake, whatever term you want to use) can be seen at dealers tank so
that rules out my KNOWN good gas because i tried different stations,
different grades, isopropal, that chevron techron stuff, and sea foam
sprayed thru carbs.The first motor had the plugs pulled at dealer after
idling in tank for about 40 minutes these were as follows one tan and
one a little darker, tan to black , just for kicks i changed both plugs
, problem still there.The second motor that does this less frequenty
the plugs are between a dark tan and black but definately not
fouled.Idle speed was checked and set per specks.I'm told by Dealers
that that they sell tons of these with no problems, I troll for hours
at a time, is a constant bad misfire and stalling normal (they start
right back up ? I was only looking for the same performance i got from
14 years of trolling with a Yamaha 15 2 stroke, it never skipped a beat
and only changed the plugs once a year. Anyone else have this problem
or symptom.


I had a 2000 Honda 15 with similar but more severe problems.
It ran rough and eventually fouled plugs if I trolled for
very long. Several steps were required to completely solve
the problem.

1) Install a hotter thermostat. The dealer should have this
in stock and it's easy to do.

2) Install hotter spark plugs. NGK DR5HS (Honda
#98066-55716) worked for me.

3) Have the dealer remove the epoxy sealed cap on the idle
mixture screw and adjust for best idle mixture. The factory
setting was too rich.

The explanation was that the factory set up was more
appropriate for keeping cooling passage deposits low in warm
water under high throttle operation. If you boat in cooler
water and tend to run at low speed the motor doesn't
maintain proper temperature.

-rick-

-rick- wrote:
hondo wrote:
I have 2 new HondaBF15's that basicly do the same thing, after the
proper break-in i do a high speed run down the lake and start troll at
low speed ,after around 30 to 40 minutes they have a misfire and or
will stall, one will do this approx. every 3 to 5 minutes and the other
alot less frequently but will still have this misfire and or stall, the
latter engine does run a little rough until you up the rpm's at
start-up. This misfire (could also be termed sputter,flutter, bad
shake, whatever term you want to use) can be seen at dealers tank so
that rules out my KNOWN good gas because i tried different stations,
different grades, isopropal, that chevron techron stuff, and sea foam
sprayed thru carbs.The first motor had the plugs pulled at dealer after
idling in tank for about 40 minutes these were as follows one tan and
one a little darker, tan to black , just for kicks i changed both plugs
, problem still there.The second motor that does this less frequenty
the plugs are between a dark tan and black but definately not
fouled.Idle speed was checked and set per specks.I'm told by Dealers
that that they sell tons of these with no problems, I troll for hours
at a time, is a constant bad misfire and stalling normal (they start
right back up ? I was only looking for the same performance i got from
14 years of trolling with a Yamaha 15 2 stroke, it never skipped a beat
and only changed the plugs once a year. Anyone else have this problem
or symptom.


I had a 2000 Honda 15 with similar but more severe problems.
It ran rough and eventually fouled plugs if I trolled for
very long. Several steps were required to completely solve
the problem.

1) Install a hotter thermostat. The dealer should have this
in stock and it's easy to do.

2) Install hotter spark plugs. NGK DR5HS (Honda
#98066-55716) worked for me.

3) Have the dealer remove the epoxy sealed cap on the idle
mixture screw and adjust for best idle mixture. The factory
setting was too rich.

The explanation was that the factory set up was more
appropriate for keeping cooling passage deposits low in warm
water under high throttle operation. If you boat in cooler
water and tend to run at low speed the motor doesn't
maintain proper temperature.

-rick-