Hi. I've been helping my Uncle work on a 1991 90HP Force motor that he has
purchased. We rebuilt the carburators, now the motor runs fine.

Unfortunately, we put it in the lake, and have discovered some other odd
behavior that this setup produces. First, when we bring it up to WOT,
everything goes great. But when you back it back down and try to shift into
neutral, 1) The spark advance seems to be stuck or something. It idles
back down, but doesn't come back down to it's real low idle setting. If you
push the linkage for the spark advance, the engine quiets back down and
idles normally. It's going to be hard to have someone sitting back there
all the time to return the motor to idle whenever we decide we want to stop
going fast!

Second, even if you get the motor to idle normally, you have to pull the
throttle advance all the way back past neutral, starting into where reverse
would be in order to get it to come out of gear. I have to assume this is a
linkage adjustment problem, however the manual isn't very clear about how to
adjust this.

Any help on the problems of:

1) Spark advance mechanism seems to get stuck and won't return to idle, and
2) Linkage adjustment problem for shifing so that you have to go to reverse
to get it to come to neutral.

Thanks in advance!

-BrianDP

My merc should be the same.
First, be sure you have the correct cable to the linkage on the motor. (If
you have someone move the lever forward from neutral, while you watch the
cables move, while they are disconnected, you will be able to determine
which works the throttle, the one that keeps moving until the shift lever is
all the way to the end of travel). Then adjust the "rotating thing" that
would be at the front of the engine when installed. This will increase or
decrease the distance from that point to the linkage attachment. With the
engine in neutral and the shift lever/throttle in the center, the cable
should be adjusted to the correct length where it attaches without moving
the shift linkage.
The procedure for the throttle is the same, with the throttle in neutral
(centered) and the linkage at the "start" of travel. If there is any doubt,
let a dealer check it. A small out of spec adjustment can cause wear and
eventual destruction of the gearbox. Hope this helps.
LD

"dp" wrote in message
...
Hi. I've been helping my Uncle work on a 1991 90HP Force motor that he
has
purchased. We rebuilt the carburators, now the motor runs fine.

Unfortunately, we put it in the lake, and have discovered some other odd
behavior that this setup produces. First, when we bring it up to WOT,
everything goes great. But when you back it back down and try to shift
into
neutral, 1) The spark advance seems to be stuck or something. It idles
back down, but doesn't come back down to it's real low idle setting. If
you
push the linkage for the spark advance, the engine quiets back down and
idles normally. It's going to be hard to have someone sitting back there
all the time to return the motor to idle whenever we decide we want to
stop
going fast!

Second, even if you get the motor to idle normally, you have to pull the
throttle advance all the way back past neutral, starting into where
reverse
would be in order to get it to come out of gear. I have to assume this is
a
linkage adjustment problem, however the manual isn't very clear about how
to
adjust this.

Any help on the problems of:

1) Spark advance mechanism seems to get stuck and won't return to idle,
and
2) Linkage adjustment problem for shifing so that you have to go to
reverse
to get it to come to neutral.

Thanks in advance!

-BrianDP