help...high idle on merc 115 6c 83

[rparis42]

I had been working on my bayliner last yr but decided to get me a skeeter bass boat with 115 merc engine. Took it out once last yr till I saw that the deck needed repair. My son and I with a lot of work and determination completed the wrk of stringers,foam and deck. Now last but not least the motor. My motor runs super loud and fast on idle speed (nautral). When I shift into gear...it SLAMS into gear with a loud metal to metal slam. This can't be good. I have the manual and am assuming its an idle adjustment problem. But I'm not understanding where is the screw and its location. I don't want to start the motor on muffs and leave it running long...to scared its going to blow. Please help. Thanks

 

[Hydro Mark]

Re: help...high idle on merc 115 6c 83

If you can't adjust the idle down with the idle screw, your timing belt may have slipped a tooth. This happened to me. It advanced the timing so much that I couldn't get the idle down. If the belt is old and stretched, it can slip at high rpms. Unusual cause, but it happened to me. Might be something to check.

 

[canoemang]

Re: help...high idle on merc 115 6c 83

There is no timing belt on a 83.. You may want to do a link n sync and set the idle in the water. Idle screw on these are at the bottom of the rocker arm. Or you may have your throttle cable to tight when you rehooked it all back up..

 

[sutor623]

Re: help...high idle on merc 115 6c 83

There is no timing belt on a 83.. You may want to do a link n sync and set the idle in the water. Idle screw on these are at the bottom of the rocker arm. Or you may have your throttle cable to tight when you rehooked it all back up..

Agreed. If I were you I'd disconnect the throttle linkage, have your son fire up the motor, and you set the throttle arm where you like it. Then adjust the idle screw as canoe has said to match up where your throttle arm is. Another thing to consider is that if your idle jets in the carbs are set too lean, up to a point they will cause a high idle.

 

[Chris1956]

Re: help...high idle on merc 115 6c 83

Don't forget to adjust the throttle cable to push the throttle closed. Add a bit of preload as well.

 

[rparis42]

Re: help...high idle on merc 115 6c 83

This is all great....it was a speedy answer on you guys part. I am truely grateful and I am going to give it a try. Thanks u guys...I will let you know. What happens. I'm on it.