1969 20 HP Mercury Starts Hard

[bjo]

Hello,
Wanted to begin by saying that there is a lot of helpful people around here and would appreciate any advice given.
My first boat came with a junky Chrysler 9.8 hp motor. It wasn't worth tinkering with, and I picked up a 1969 20 HP Mercury. The boat is a 14 ft. Lund and with the Mercury it really goes.
The problem is that the motor is a bit hard to start. When I first got the motor, it liked to be stared with the choke closed. After time, it began to take more attempts to get it started, especially when the motor was cold (maybe 12-20 pulls). It's no fun being stuck near the docks.
Per the advice of this forum, I got the repair manual for the motor, the Seloc guide. I still am a but confused as to where to start. Any advice appreciated. Should I be looking at the ignition points? Or does the motor have a real deal starter that might be rusty after forty years?
Wanted to add that when started, the motor feels like it runs pretty healthy. Moves the boat at about 25 MPH acc. to the GPS. This is my first attempt at outboard motor repair, and all I really have to go on is the manual.
This is a pull start motor, and it feels like when I pull the chain, there is no tell-tale "put put" sound/feel for a while. I can tell when it will start soon because the chain will become easier to pull and I can feel the flywheel (I believe) begin to make revolutions more freely.
Sorry, I know this information is a but unorganized, but I am trying to give all information possible and fix the thing on my meager budget.
Thanks,
Brian

 

[bjo]

Re: 1969 20 HP Mercury Starts Hard

Consolidated to first post

 

[mark mcj]

Re: 1969 20 HP Mercury Starts Hard

Since it runs good once it's started I check the primer bulb and fuel lines.
Make sure you're getting fuel up to the carbs to start it.

 

[bjo]

Re: 1969 20 HP Mercury Starts Hard

I did need to change two fuel lines. I changed them to automotive grade fuel lines of the same diameter and made sure they were not kinked. What can I look for as far as the primer bulb is concerned?
With the cowl off, as I open the choke, I can see the assembly pivot on a hinge like it is opening as it should.

 

[Chinewalker]

Re: 1969 20 HP Mercury Starts Hard

If the motor is new to you and you're not familiar with its service history, I would strongly suggest a tune-up kit (points and condensers), and a waterpump impeller. Weak condensers or old points can lead to hard starting as it won't make strong spark at cranking speeds.

 

[corm]

Re: 1969 20 HP Mercury Starts Hard

Hi,

The first thing I would do is what Chinewalker said.
These engines started in 2 pulls when tuned right.
1st pull choked, 2nd pull no choke.
Check the top crankshaft seal for signs of it leaking when doing the points.
There will be a lot of oil in where the points are at.
If doing the pts & cond does not help then I would replace the
bottom crankshaft seals. While in there make sure the bottom
check valve is working. That will cause the problem too.
Although I have resealed a lot of the 20's most of the time it is the points
that are giving you the trouble.

 

[bjo]

Re: 1969 20 HP Mercury Starts Hard

Thanks for the advice. I will look into replacing the ignition points. The waterpump was replaced soon before I got it. I can get the points and condenser from a Mercury dealer for a reasonable price?