Why Won't This Thing Stay Running?

tonka_shores

Cadet
Joined
Jan 21, 2006
Messages
22
It's a 1972 Merc 888 (Ford 302) with a Holley 4 barrel carb. The past several times out, I start out from the dock, it will run up on plane (3000 RPM) for 15 minutes until I get to a no wake zone. When I throttle down, it sputters and dies. Won't start for love or money. I wait for about 20 minutes, it starts and runs great the rest of the day--fast, slow, anything. I've replaced the fuel filter, switched from one tank to the other. Last Sunday it ran like a champ. Today, I barely made it back to the dock. I took the site screw out of the primary bowl and the level looked right. When I push the accelerator forward, I get a decent squirt of gas in the throat. So what gives?
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Why Won't This Thing Stay Running?

When was the last time it had a full tuneup? Plugs, points, cap, rotor, dwell set, then the timing, advance timing check, compression check, carb adjust. You know, the yearly maintenance stuff.
 

tonka_shores

Cadet
Joined
Jan 21, 2006
Messages
22
Re: Why Won't This Thing Stay Running?

Plugs, points, cap, rotor, timing, all done late last season. We probably don't have 20 hours on it this year. Had a compression check this summer--mid-season. Checked out OK. We use only 92 octane, non-oxigenated gas with a lead substitute additive. Did I mention that it was a 72?

It has an electric choke. Starts at the turn of the key when cold (after 2 pumps of the throttle). The choke opens within minutes. Last sunday it ran like a scared rabbit. Today I couldn't keep it running to save my life.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Why Won't This Thing Stay Running?

Plugs, points, cap, rotor, timing, all done late last season.

That is probably your problem. You need to do it in the spring as part of your "Get ready for the new season" maintenance.
After you did all that last year it just sat around most of the time.
You probably just need a set of points because they are glazed over from setting and getting high resistance.
You may have low hours, but for points sitting is about the same as using.
 
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