1981 Mercury 25hp Very Difficult to Start

[Cordovakid]

I have a 1981 Mercury 25hp manual start which is a great motor, once you get it running. Plenty of top end / throttle response - even will troll down nicely. When the engine is warm, guaranteed one pull to get her going. However, starting this beast cold is a major pain. Here is my current cold start procedure:

(a) Prime bulb hard.
(b) Turn idle / enricher knob clockwise all the way to "prime".
(c) Re-check bulb is hard.
(d) Pull to start once.
(e) Turn knob counterclockwise one notch to take off the primer, but leave spark advance to fast idle.
(f) No start until about 20-30 pulls, even if I prime it one more time, but afraid any further priming will flood it.

Am I missing something here? I have not cleaned out the carb and fuel pump yet (kit on order). Is it possible my primer button is malfunctioning / plugged / stuck? If so, how do I check this problem out? Will this motor start without the primer functioning (ie. priming the bulb only). Also, does anyone know of the "factory correct" method for starting this motor? (my OEM Service Manual is also on order...)

Any other advice on where I might be going wrong would be great - thanks.

 

[Maxz695]

Re: 1981 Mercury 25hp Very Difficult to Start

does the motor have a choke? no mention of it was made by you

 

[Cordovakid]

Re: 1981 Mercury 25hp Very Difficult to Start

No actual choke - my understanding is that this motor has an enricher primer button which becomes depressed by via the rod attachment on the idle knob, which advances the spark. When the spark is in the fully advanced position, an arm comes down to depress the primer button, I believe called an "enrichment valve" in Mercury literature.

 

[Cordovakid]

Re: 1981 Mercury 25hp Very Difficult to Start

Has anyone had any experience with the enrichment primers sticking / failing on these early 80's Mercs? I just want to be careful with the carb assembly since parts are NLA.....

 

[Cordovakid]

Re: 1981 Mercury 25hp Very Difficult to Start

OK, still working on this one. Cleaned out the enricher port with cleaner / air. Motor is getting better at starting up now - down to 10 pulls or so. I have the factory service manual (which has been VERY helpful...), but unfortunately it doesn't list the factory cold / warm starting procedures. Does anyone out there have access to this information? I figure it can't be that much different than most other 2-strokes (ie. pump bulb, choke / enrich, pull start), but I would like to just make sure I'm doing everything correct here. It really is a great motor once it's warm - just getting it cold started....aarrrgghh.