150 Merc' Help

[jesse@tsiaviation.com]

I have a new to me 150 Mercury 2001' motor, when the motor is in nutral it's revving at 1200 rpm's (on the hose) and makes a crackling sound when going into gear.

Any suggestions?

[conchcuzzy]

Is this an optimax? Perhaps a previous owner set the throttle advance screw a little too far. Sometimes this is done to compensate for the tough cold start these motors are known for. In fact I believe they are supposed to idle at about 1,200 until the engine temp reaches 145 degrees.
HTH

[Bigshrimpin]

Two Links:

Service manual
http://boatinfo.no/lib/mercury/manua...00-225.html#/0

everything you ever wanted to know about merc v6 2.5L engines.
www.screamandfly.com

[Bigshrimpin]

Crackling or grinding when shifting?

What is RPM when in gear at idle . . . not on a hose?

sounds like simple cable adjustments.

[jesse@tsiaviation.com]

I'm going to take it to the water tomorrow and see if the RPM's go down once I the motor warms up. If not ill adjust the idle screw.

I just change the impeller a few days ago.

Yes it's a grinding sound.

Thanks for the feedback guys.

[Bigshrimpin]

RPM in fwd gear at idle should be about 700rpm.
1000 - 1200 is about right at idle in neutral if I remember correctly.

[jesse@tsiaviation.com]

I thought it was making the grinding noise bc it was at 1200 rpm's in nutral. I'm taking it the water in the morning I'll let you know what I find.

Thanks again!

[jesse@tsiaviation.com]

Big shrimp

Took the boat to the water and adjusted the idle screw, brought it down to 800 and she ran fine. Thanks for the help

[eggsuckindog]

it will idle higher on the hose

[jesse@tsiaviation.com]

I was still at 1100 rpm's at the ramp today, so I adjusted the idle.