Idle problem on 1995 Evinrude 70 hp

rlk

New member
I have a 1995 oil injected Evinrude 70 hp that has an idle problem. This past winter, the carbs were rebuilt. Due to a busy spring, I was not able to get the boat into the water until this past weekend. The engine idles way too fast. Each time you put it in forward or reverse, there is a loud "clunk" when the gears engage. Going from forward to reverse when docking is rough on my nerves as I can't stand all the "clunks". Also, at idle speed, the boat moves too fast to troll for fish.

I did not have time to diagnose the problem as a thunderstorm was on the way with lots of lightening. Got the boat docked, and headed to the house.

Does this model Evinrude have an idle adjustment that I can turn to slow down the idle? Anyone have picture they can post?

Thanks, Bob
 

Doc

Liquid Addiction
Staff member
Hey Bob I can empathize. I had my carb rebuilt just last week and it is not idling just right either. I know there is an adjustment or two but I don't know where. :pat:

I would guess that all carbs can be adjusted ... but that is only a guess.
 

waybomb

I'd rather be blown
Doc

On the base of the carb, primary side (front) you'll see two small screws on either side fo the front of the base. Those are your idle circuit adjusting screws.

Once the engne is warm and idling, turn them in, and as you do so, and the screws go further in, the idle will drop. Back it off slowly until you get the highest rpm.

A better way is with a vacuum gage. Connect the vacuum gage to any intake manifold vacuum fitting. Adjust both screws so you get the highest vacuum reading. Both screws should be screwed in about equally.

Then adjust your idle speed screw, which is the big screw on the side of the carb that acts as a stop to having the butterflies completely closed. 600 rpm would be nice.

If, after adjusting the small idle circuit screws, the rpm is too high, reduce the speed with the big screw on the side, then go back and re-adjust the idle circuit screws. You may have to do this a few times.
 

rlk

New member
Fred, thanks for the insight.

You responded to Doc, and I can't remember if he has a 70 hp Evinrude or not, but assuming your instructions will work on my outboard, I'll try your suggestions this coming weekend.

Thanks, Bob
 

waybomb

I'd rather be blown
I am pretty sure doc was talking about the Rochester carb on his inboard.

I know very little about outboards. Adjusting the carbs on an outboard may or may not yield the same results.
 

rlk

New member
Finally got this problem resolved by resetting the timing. There is a sticker on the engine that states to set the timing at 17 degrees BTDC. The mechanic working on the engine had to set the timing at 14 degrees BTDC in order to get the idle speed down to around 1100 RPM out of gear or around 850 RPM in gear.

He could not explain why the timing had to be changed, but I'm much happier with the way it idles now.

Can't stand that loud "CRUNCH" when you put it in gear.

Another problem has developed though, and I started a new thread on that "Problem with 70 HP Evinrude Outboard". Any help on the new problem will be greatly appreciated.

Thanks, Bob
 
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