| Papaboat |
"I run full speed, but after a few times
trolling, I seem to loose full throttle when I am heading in. The
boat won't come up on plane and every once in a while the motor
will act like it gets more RPMS and then bog back down. I pulled
plugs and one seems to be fouled up. Any ideas? I use 50:1
mixture.
Also, the nut on the flywheel, is it a left handed thread?
Thanks in advance"
|
2001-06-09
07:42:00 |
| J.B. Cornwell |
"Howdy, Papa. What sort of boat do you have
this 9.9 on? How fast and how long do you troll before the fouling
shows up? Do I understand correctly that only one plug fouls and
that it is always the same one? Do you get smoke when trolling?
I don't recall whether that 9.9 used one or two carbs but it
sounds like you have one cylinder idling (trolling) too rich or
your plugs are too cold.
Idling is an unnatural operation for most 2 strokes and
frequently causes fouling and carbon buildup. Check your
compression for balance and try decarbonizing it. Check your
manual for a different plug recommended for extended low speed
operation, and check the setting of your Carb mixture at idle.
Hope that helps.
JB "
|
2001-06-09
10:49:00 |
| Papaboat |
"JB,
Thanks for the reply.
Seems that there is no pattern to how long I troll, it can be
an hour and everything is ok, or it can be 10 minutes and then I
have a problem.
It is a single carb. And yes, seems to be the same plug that
fouls. Any chance I could have a weak coil ?
Also JB, I was going to look at the points, but having trouble
pulling the flywheel off. Do you know if the nut has a left handed
thread?
Again, thank you for your time.
Papaboat"
|
2001-06-10
06:36:00 |
| J.B. Cornwell |
"Howdy, Papa. Could be a coil. Could be some
intermittent electrical/ignition problem that you might find under
the flywheel. I do believe that the flywheel nut is left handed
(counterclockwise removes it). I would still want to know if the
compression is balanced.
Failing results on the above I would examine the reeds.
Good luck.
JB "
|
2001-06-10
08:43:00 |
| Papaboat |
"JB, how do I check the compression? Thanks
again.." |
2001-06-10
09:52:00 |
| J.B. Cornwell |
"First you need a compression guage. They
are not very expensive, or you might have a buddy who can loan you
one. There are two types: one with a rubber cone that you simply
press into the spark plug hole, and one that screws into the
sparkplug hole. If you have a choice, get the one that screws in.
It is much more accurate and you can use it while operating your
starter rope.
Pull both spark plugs, attach the guage and spin her over. Note
what the guage reads, typically 120 to 150lb. Now do the other
cylinder. They should be within 10-15lb of each other and both
over 100lb. If you have the kind of problem that could be causing
your symptoms the cylinder that fouls the plug will be quite a bit
lower than the "good" one.
Let us know what you find.
Good luck.
JB "
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