18HP Evinrude runs at idle speed only while in gear

[Kdubya]

Idles fine at high idle and low idle speeds. Will only run at low speed when "in gear" (forward or reverse). Any suggestions?

 

[Swiftwrench08]

Re: 18HP Evinrude runs at idle speed only while in gear

I think a good place to start is to check and adjust the timing advance. It sounds like the sync and link is not tuned correctly. If there is still an issue once the timing has been set than you need to look at fuel delivery. The reed plates could be sticking causing the motor to not get enough fuel when the rpm is increased.

 

[OptsyEagle]

Re: 18HP Evinrude runs at idle speed only while in gear

I am confused. You say it will idle high and low and will run in gear at low speed. So are you saying that you are not getting the top end performance out of the motor. Perhaps you could give us a little more info on what your problem is.

 

[Vintage Boat Guy]

Re: 18HP Evinrude runs at idle speed only while in gear

Alright I have a 1959 18hp Evinrude and have run into this problem before on other motors. What you need to do if it won't run to your satisfaction in gear is to adjust your idle for low or high speed because when you are not under load the motor does not have to work as hard. This should do the job. Usually crank in the idle until tight and unscrew between 1-1.5 turns out, then adjust from there, its simple.

 

[nwcove]

Re: 18HP Evinrude runs at idle speed only while in gear

also a bit confused by the wording of the post, but trying to read between the lines,........ id guess you may be running one one cyl.

 

[HighTrim]

Re: 18HP Evinrude runs at idle speed only while in gear

I think that he means that it wont go to a low idle in neutral.

This is hard to evaluate with a brief description alone. One mans interpretation of a good low speed idle may be different from someone else's.

It may be a mis tuned low speed needle, or a number of different things. Any chance of seeing a video?

Vintage Boat Guy, I believe you are referring to the low speed needle, not the idle.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

Sorry, I was trying to be brief, not confusing. The motor ran fine til I hit a wake a few weeks ago. After I hit the wake, it acted as if it was only getting enough fuel to run at idle speed, despite the tiller throttle being turned to "wide open". It will crank fine, and the throttle will run the RPMs high in neutral, but not in gear. When the forward or reverse is engaged, the motor will not run full speed. It idles fine, just won't run full speed.

 

[HighTrim]

Re: 18HP Evinrude runs at idle speed only while in gear

Ok well that was totally different from what we thought! lol

Running on one cylinder? Have you checked compression and spark on both to start?

What model/year are we talking about here anyways?

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

High Trim, I can't make a video. Maybe this will explain further:
The throttle works fine while in neutral. It cranks, revs, etc. The problem is the performance while in gear (forward or reverse). When placed into gear, the motor won't run wide open, only just over idle speed when in gear.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

Not sure of the year. It's "old". Bought it used. I'll try to post a pic.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

Model FD-17B
Website says its a 1963.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

Haven't checked compression. May have to take it to an outboard mechanic.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

Took some pics, but can't put them on the site.

 

[the machinist]

Re: 18HP Evinrude runs at idle speed only while in gear

There is a possibility that you may have a partially sheared flywheel key throwing it off time slightly. Or you might check your gearbox oil, you may have the gears dry & creating more resistance.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

I'll be happy to email the photos to anybody that is interested.

 

[Kdubya]

Re: 18HP Evinrude runs at idle speed only while in gear

The machinist, I think I'll just take it to an outboard mechanic. I'm afraid I'm out of my depth with outboards. Thanks to all for the suggestions.

 

[OptsyEagle]

Re: 18HP Evinrude runs at idle speed only while in gear

I suspect you are dropping a cylinder. Good luck.

 

[Vintage Boat Guy]

Re: 18HP Evinrude runs at idle speed only while in gear

Yes I was talking about the low/ high speed needle valve but forgot what it was called, old motors biggest problem creator is usually the carb