1980 Merc 25hp - Hard Starting Question

[Cordovakid]

Hey - so I've tried just about everything with this motor over the years. Starts great warm, but it a bear to start cold. Pump bulb hard, turn idle up and engage the enrichener (no choke on this model). My starting procedure is to leave the enrichener engaged while pull starting. Takes anywhere from 15-25 pulls typically. Then, she will start all day long on one pull until overnight, then it's another 20 pulls to start in the morning.

Questions: 1. I notice the bulb will not be hard if I leave it for a couple of hours, after priming hard. Would the fuel possibly be leaking into the fuel pump past the diaphragm causing a flooding situation?

2. How does that enrichener actually work - it's not a choke, so I am wondering when the little plunger depresses into a small chamber at the side of the carb, does it shoot fuel into the throat, or does it block off an air intake, "enrichening" the mixture?

I have good hot blue spark, I know fuel is getting to the carb. One other thing, my plugs foul black after only a couple of runs on the lake. I presume this indicates a rich / flooding condition, but not sure why? Any help would be appreciated guys.

 

[Faztbullet]

#1 ...normal as leaking past check valve in primer bulb.
#2....It shoots fuel into throat. Proper cold starting is to pump up bulb,turn enrichener to right to advance timing, pull/push primer knob several times to add raw fuel into throat and then crank. It it doenst hit after 4-5 pulls repeat above.

 

[Cordovakid]

Thanks for the good info...So, in relation to Item #1, is the fuel possibly leaking past the check valve into the carb? And, would you recommend for this carb, a Tillotson BC1C, to keep the enrichener plunger depressed while starting, or deactivate the plunger after priming a few times, and just leave the timing advanced / throttle increased? Sorry for the trivial questions - I know how to start a cold outboard - prime, choke, pull. However this one is just driving me nuts. I can't figure out if I am flooding it, or not giving it enough gas.

One other item - if there is an air leak in the fuel lines, either internal to the fuel pump or the tank to engine line, would that introduce air into the carb which could complicate things? I have the OEM service manual for this motor (very helpful, BTW), but would love to have know the original cold start method from Merc.

Thanks again for any help.

 

[Mi duckdown]

what fatzbullet posted.

 

[Cordovakid]

I also agree with duckdown, for sure. Will just have to try her again when the snow melts, for another year of building up the muscle in my right arm.....haha. Last stupid question before the weekend - I know it's obvious if fuel is pouring out of the carb, indicating a flooded condition. But, otherwise, what's the best way to tell if you have flooded the engine, as it seems to take me 20 pulls no matter what on a cold start.

 

[Mi duckdown]

It is hard to flood that enricher system. plus the primer bulb is only needed to fill the carb. ONCE started the Bulb will not be hard. That said. rebuild enricher pump/ button for ten bucks.

 

[heyblue]

Try squirting some starter fluid before pulling. If it fires up easy, probably not flooding. It is hard to flood a cold engine. Also, in the adjustment procedure after a rebuild of carbs it states "setting the ideal jets more rich than lean is recommended" "hard starting is related to too lean a setting." Lastly, I had a 1979 80 HP hard starting as well as staying running in idle in gear. The idle timing was off.