need help with stange starting problem

[xanthras]

We have a 1985 merc 3.0 140hp i/o. So this year it is doing something strange. To get the thing started I have to turn it over for what seems like forever in addition to giving it a ton of gas. This usually ends up with the battery dying before I get it started. Once I charge it, turn it over a bunch more times with more gas it starts. Once started it runs totally fine. lf I let it sit for a few hours it does the same thing but to a lesser degree. Where should I start troubleshooting this. Points and condenser were new last year. Distributor only a year or two old but looks new. Not sure on the plugs age. THe plug wires are a couple years old. New coil this year too. Does this sound like a poor spark/electrical issue or a fuel/carb issue? Thanks!

 

[maxxman04]

Re: need help with stange starting problem

could be a host of things. something in ignition system, fuel system. a few quick checks can narrow down. make sure carb is getting fuel. choke working right. good points, plugs, cap, rotor, wires. timing. all this is basic maintenance. and it is possible for new parts to deteriorate over a long enough time if they sit with no use. also, how old is the gas?

 

[xanthras]

Re: need help with stange starting problem

The gas is 5 gallons of new gas and maybe 2-5 of gas from last season (including some stabilizer) The fact that it runs well once started makes me think it could be something along the lines of it getting gas as opposed to electrical. Is there more to the choke than the choke plates closing?

 

[PitchFork]

Re: need help with stange starting problem

Sounds like choke as I had the same problem with my 5.0L and 4bbl Rochester. The choke plate should be almost closed my manual for my engine says within 3/16" from air horn wall on a cold start. I had to bend the choke rod to get there. My choke was always fully opened when I bought the boat 2 years ago. I did not know any better so I poured 4 tablespoons down the primaries and then it would start right up from a cold start. It would then run good the rest of the day.

 

[Brad634]

Re: need help with stange starting problem

Definatly sounds like a choke issue make sure that the linkage is moving freely and that it closes when you are first trying to start it.

 

[searay3]

Re: need help with stange starting problem

Don't have my manual in front of me right now, but I believe the choke should close completely at cold start, and the choke pull down will open the door to 3/16.

 

[searay3]

Re: need help with stange starting problem

Just to be sure, cold start procedure is to pump the throttle open a couple of times so the accel pump throws a little fuel down into the manifold, throttle 1/4 open, turn the key. Be prepared to pull the throttle back when it fires.

 

[Bondo]

Re: need help with stange starting problem

or a fuel/carb issue?

Ayuh,.... It'd be nice if you opened the motor hatch,+ Observed exactly what Is working,+ What Ain't.....
Just for reference....

It takes Fuel, Fire,+ Compression, at the right Time for the motor to Run....
Instead of cranking your battery Flat all the time,...
Do a Tune Up,+ Service.... Just to see what's workin',... or Not....

My guess is, it's starving for Fuel....

 

[xanthras]

Re: need help with stange starting problem

Thanks for all the replies guys. Sounds to me like I am facing a fuel /choke issue. I will grab a spark tester just to be sure. I am going to check that choke position on cold start. Wont get up there till this weekend. Thanks in advance. I will post my progress!

 

[cr2k]

Re: need help with stange starting problem

One more very quick test...Run a jumper wire form the pos batt to the side of the coil that DOES NOT go to the distributor. If it fores right up you have a solenoid going bad. When you hit the starter there is a terminal that send a 12v surge to the coil to boost it during cranking. When contacts get bad in solenoid this dont happen. either replace starter, solenoid or add relay to jump this.

 

[xanthras]

Re: need help with stange starting problem

Ok so here is my update. I tried to get it to start her up and got just about nothing again. Looks to me like the choke plate is working. As soon as I pop out my shifter to what I call the neutral setting (as in, all I am controlling is the throttle) I see the choke plate drop flat. I started turning it over as I pump the gas and got nothing. Later on I get my dad to take a look. He sets the shifter into the neutral setting, and gives it 4 pumps then pulls it back to just ahead of idle. the thing kicks over.(although not to smoothly) he gives it more gas and it is running. What is the deal here? I have now done it this way several times and so far so good. What is strange is that we have never had to do it this way. We usually pumped the gas several times, set the throtle at half or wherever. I didn't matter where it was and it would start...what could have changed? Even my dad recognized hat it was much more sensative than the previous 15 years.

 

[bigskiohio]

Re: need help with stange starting problem

open your choke plate up and give it some air you really dont need choke on 90 deg day. just adjust it open a little or to test hold open with screwdriver and see if it starts easier ,if so adjust your choke, change your plugs anyways.