1985 75 HP Mercury Idel/Shift Problem

[berrabbit5849]

I have a 1985 75 HP Merc. When I shift into Rev. It dies. If I set the Idel stop for higher RPMs it works ok. Around 1200 RPM. I am worried that this might damage the gears when shifting. Also idel speed is too high with this. Any info on this would be appreciated. I also have to choke it pretty often to get it started. Even after it warms up.

 

[Laddies]

Re: 1985 75 HP Mercury Idel/Shift Problem

It sounds like the idle mix is to lean, someone many have adjusted in neutral

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

When I remove the wrap around cover where will I be able to see the adjustment screews at to set them ?

 

[Laddies]

Re: 1985 75 HP Mercury Idel/Shift Problem

Yes they are in the front face of the carbs at about 1 oclock

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

I removed the cover and all I saw was 1 butterfly and an adjustment screw at the 1 oclock position like you said. I turned it 1/2 turn out. Do not know when I will get to try it out. Do I keep backing off on this adjustment until it goes in Rev without dying ? What will this do to my regular acceleration ?
I was running slow the last time out and everytime I pushed the choke switch in it sped up for a while then went back to the speed I was going. Did this several times. Does this tell you anything ?

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

Caqn anyone answer my last question?

 

[Laddies]

Re: 1985 75 HP Mercury Idel/Shift Problem

If bumping the choke speeds the RPM then the engine is definitely is lean but you have 2 carbs to adjust, agood place to start is with both at 1 1/2 or 2 turns from the needle being screwed all the way in.

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

Thanks Any idea where the 2nd carb is located? I removed the front cover off of the carb housing and all I saw was 1 carb. at the very top. There was an adjustment screw at the 1 o'clock position and another I think at the 10 o'clock pos.

 

[Chris1956]

Re: 1985 75 HP Mercury Idel/Shift Problem

There shoud be another carb directly below the top one.

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

"Thank you" to all of you for your help. I loaded it up today to go fishing and before I left I backed the two idle adjustment screws out 1/2 turn. It fired up the first time and went into reverse all day with out stalling.
What should my idle rpm be?

 

[berrabbit5849]

Re: 1985 75 HP Mercury Idel/Shift Problem

Took my boat out two weeks ago and it ran like a champ. Took it last Sat and it wouldn't hardly run. Removed the cover to adjust the idle screw and saw one spark plug arcing to ground. Replaced all plug wires today. Found 2 bad.
Carbs are backed out 2 rounds. I didn't have any water hooked to it so I didn't try to run it very long. Will hook the water hose to it tomorrow.
I got it to start but when I backed off of the trottle lever it dies. How far out can I adjust the carbs? What should my idle rpm be?
Any e-mail would be appreciated ch5849@windstream.net