sherwin dubren wrote:
For years now, I have been fighting the problems keeping my 4
stroke Ymmaha T9.9 running. Even with adding preservatives to
the gas tank, replacing the fuel delivery system, and adding
a 19 micron filter inline with the gas feed, the tiny jets on
this engine occasionally block up. Nothing helps short of tearing
down the carb to clean them. Most of the modern gas engines have
these small jets that continually block up. Gasahol is mostly to
blame either because it dissolves any loose dirt in your system
or breaks down into something that eventually blocks the carbs.

Now we have an increase of alcohol being pushed by our farmers
to 15 per cent instead of the current 10 percent. This is sure
to make the problem worse. The engine manufacturer's have not
come up with a really good solution. Just band-aid fixes like
adding inline filters and preservatives to the gas. This is
taking all the fun out of boating and can even be a safety issue.

Sherwin

My neighbor, the fuel polisher, is getting more and more calls to
suck out old gasohol and dispose of it. Makin money!
BTW, the problem in the 4 stroke little engines is an epa deal. There
is a hidden adjustment on most.
On the Hondas, there is an adjuster on the side of the carb that is
limited by a little cap. Use a little torch to heat the solder holding
the cap on. With the cap off, a little extra turn and the engine will
run great.
The Yam probably has a cover over the adjuster as I had on a little
road bike.
G