Hard Starting

Joined
Oct 22, 2007
Messages
2,598
1973 Merc 7.5 which I'm repairing. It has good compression, good spark, and once I get it started it idles perfectly and runs good up to full throttle in gear. The only problem is that it takes FOREVER to start when cold, somewhere around 20 or so pulls. Any thoughts on what can cause this?
 

coastalrichard

Lieutenant
Joined
Apr 6, 2009
Messages
1,255
Re: Hard Starting

Well...we all know that Merc's like, no make that love gas....is it getting enough priming?:rolleyes:
 
Joined
Oct 22, 2007
Messages
2,598
Re: Hard Starting

I pump it 'till the bulb is solid and choke it, don't know what else I can do beyond that. I used to have another old 7.5 which always started with just a couple of pulls, I really think this one ought to be able to do the same.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Hard Starting

Does this one have the pull choke with the cable? Make sure it's adjusted so that the cable pulls the choke all the way closed...
 

Sunfish12

Petty Officer 1st Class
Joined
Feb 6, 2011
Messages
260
Re: Hard Starting

You said it takes forever to start cold. does it start right up when warm?
 

Sunfish12

Petty Officer 1st Class
Joined
Feb 6, 2011
Messages
260
Re: Hard Starting

Try opening the choke just a hair to see if it starts.
 
Joined
Oct 22, 2007
Messages
2,598
Re: Hard Starting

I've tried it with the choke all the way closed, cracked open, half open, etc. etc. When it's cold it just flat refuses to jump to life within a couple of pulls like I think it should. After it's been running I can shut it off and it restarts instantly.

I'm tempted to get a carb/fuel pump kit and replace all the gaskets and diaphragms, but since it runs so good once it finally does start that I'm not sure if that's the problem.
 
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