150 Merc' Help
 

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?

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

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

Crackling or grinding when shifting?

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

sounds like simple cable adjustments.

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.

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

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!

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

it will idle higher on the hose

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