1986 20HP Mercury outboard

[MarvinRSchwartz]

I’ve done everything that I can think of to get this engine started but it just will not start. List of things I’ve done carburetor kit new plugs, ignition coils, replaced flywheel key, new gas.
I have spark I have approximately 110 psi pressure for compression I have fuel. Everything under the flywheel looked OK. If I was to guess which I am it almost seems like it’s out of time. However, I don’t know how to time these engines. Any help would be greatly appreciate it.

 

[flyingscott]

Have you checked spark jumps a 1/4" air gap? Have you tried spraying a fuel mix into the carb? Choke working?

 

[MarvinRSchwartz]

Yes on spark. Yes on spray and yes chock works.
The key was sheared and I replaced iit. But it still seems like it’s not timed correctly

 

[racerone]

Tried switching plug wires ?

 

[flyingscott]

Check the plug wires. Is the base gasket of the carb on right? Did you check to make sure the primer is squirting? As that motor does not have a choke.

 

[jimmbo]

A bit delayed... Welcome to iboats

How long have you had this Engine, and did it run fine last Season?

 

[MarvinRSchwartz]

I bought it new and yes it ran .
I finally got it to run but will not idle well I guess I dont know enough about these engines to be working on it. Thanks for the help

 

[jimmbo]

I'm not sure if the last part was Sarcasm. Often, someone will post about a Problem, and it takes a while to Ferret out that they have No History on the Engine, what has been done to it, when it started acting up or for how long...
It is amazing how many people will buy an Engine blindly, without ever running it, cause the seller said it was in excellent shape and ran fine, forgetting that to mention that that was when the engine was brand new.
We can't see your motor and can only go with what you tell us, so the more info given to us at the beginning, the better, as it will certainly help, when trying to troubleshoot.
In your initial Post, you have some worry that the Timing is off. Since the late 60s early 70s, most engines never need to get the Timing adjusted. Unless someone has went and messed with it, it should be fine, so a verification is fine, but don't start adjusting, unless it is off and you have the Correct Service info. FYI, there is no Idle Timing Spec on these 2 stroke engines. Many Carb-Ignition syncs have been messed up by DIYers trying to adjust things like they do on older Car/Truck engines.
Which brings me back, the comment about more info. If someone has adjusted/misadjusted a linkage and or Timing, please mention it, as it saves many of us from looking elsewhere, perhaps finding the initial Problem but because of other changes, may still not run right

 

[Chief78]

You might consider a new Switch Block. My ‘86 75 HP Mercury was acting the same way. Now runs perfectly.