Starting!!

[dotsadie]

I have a 120 hp 2.5 liter mercuiser motor. Yesterday it took a little time to get it started, we have had rain for the last couple of weeks. It finally started opening the choke. Today i tried again to get it going and all it would do was flutter trying to start. So i took the fuel filer out and put a new one in and now it will not even try to fire if it had no spark. I have also put Quick start in the carb an still nothing.
Do you think i have a crack distributor cap or moisture in the spark plug wires?
Ps the weather has been cold and wet for the past two weeks or so.
Any help would be help full before going to dealer.

 

[Another retired guy]

Re: Starting!!

Hi. There are many possibilities here but assuming it was working ok before the wet weather, then I would also suspect the ignition. Sounds like a full "tune up" is required - distributor cap, rotor, HT leads maybe?

 

[Brewman61]

Re: Starting!!

If "Quick Start" is like ether or starting fluid, and you didn't get anything from using it, you have a probably spark problem.

 

[dotsadie]

Re: Starting!!

Have tried pulling out the first spark plug and grounded it and got a spark. Tried the next one and had nothing.went back to the first plug and tried it again, this time nothing.
Now i am going to pull the coil wire out of the rotor cap to see if i have spark. If get spark i get spark does this mean something is wrong in the distributor?
Ps; does anybody out there have a site where you can get pitures and parts list for a 120 hp 2.5 liter mercrusier engine?

 

[Another retired guy]

Re: Starting!!

Have tried pulling out the first spark plug and grounded it and got a spark. Tried the next one and had nothing.went back to the first plug and tried it again, this time nothing.
Now i am going to pull the coil wire out of the rotor cap to see if i have spark. If get spark i get spark does this mean something is wrong in the distributor?
Ps; does anybody out there have a site where you can get pitures and parts list for a 120 hp 2.5 liter mercrusier engine?

If you get a consistent spark from the coil wire then you either have a problem in the distributor ( bad rotor contact or corroded contacts ) OR you have a problem with one or more of the spark plug wires. I would change the cap first, and then the wires.
I assume this distributor has contact points? Not electronic? If inconsistent spark from coil wire, then replace points & condenser.
And if none of the above work- replace the coil!

 

[dotsadie]

Re: Starting!!

Have consistent spark at coil wirer. Have cleaned the points, rotor and sprayed the cap inside and outside with WD40. Now it is trying to start but keeps back firing through the carb.

 

[Another retired guy]

Re: Starting!!

If you removed the spark plug wires - did you replace them in the correct order?

 

[Don S]

Re: Starting!!

Replacing cap and rotor is just a maintenance item like changing the oil and filter.
Plug wires may also be bad if you are getting inconstant spark to the plugs, or even faulty spark plugs.

 

[Another retired guy]

Re: Starting!!

If you removed the spark plug wires - did you replace them in the correct order?

If the plug wires are connected correctly, then another possible cause for the backfire is a cross-firing problem inside the cap. WD40 conducts electricity so spraying it inside the cap could provide alternate paths for the high voltage. Clean the cap thoroughly or, better still, install a new one

 

[dotsadie]

Re: Starting!!

I only removed one at a time referring to the spark wiers so that part will be ok. Am going to replace the codencer, points and rotor today.Will let you know how this turns out. PS; would have change tthe Cap as well but the Dealer didn't have one. Will do this latter.

 

[Another retired guy]

Re: Starting!!

If you still have problems after installing those parts ( and removing the WD40 from inside the cap), try starting the engine at night in the dark. Look for sparks jumping across the plug wires. If you see any then change the wires.

 

[dotsadie]

Re: Starting!!

The problem ended with who ever was doing the service on this engine striped the screw hole which holds the points in place.
Replace points,condenser and rotor now it starts up with no problem.
Thanks again for all your help. It shows to check everything out even down to a screw.

 

[dotsadie]

Re: Starting!!

Still having a small problem. The butterfly on the carb is closed when i want to start the engine.It doesn't want to start. If i open the butterfly open about 1/4" it will start but run ruff. If i open the butterfly more to the full open position it will per like a kitten. A friend of mind says it is getting to much fuel and not enough air,this intern will foul my plugs.
Would this be caused from a bad electric chock? Have check for power and that part of it is OK. There isn't any vacumn hoes for this carb.
All suggestion would be help full.

 

[Another retired guy]

Re: Starting!!

Does the choke open fully when the engine is warmed up? If it does open, then the choke is probably ok and your problem is a too rich fuel mixture.
If the choke does not open when the engine is warm, then you definitely have a problem with the electric controls, but may still also be running a rich mixture.
I'm guessing the choke is ok and the mixture is too rich - and yes, it will cause a soot build up on the plugs.

 

[dotsadie]

Re: Starting!!

The only time that i see the chock opening right up is when the throttle is full ahead. My engine only get up to 100 degrees.

 

[Another retired guy]

Re: Starting!!

If that's 100 F then it's much too cool - if 100C then it's much too hot! Either way you have a cooling problem; maybe a choke problem, and a fuel mixture problem. Time for a full service

 

[dotsadie]

Re: Starting!!

Now that i think about it, i don't think the gauge is moving at all. Have put my hands on the hoses and i don't feel any heat there at all either.Maybe the thermostat is wide open allowing the water to pass right through causing the chock not to work.
I am no mechanic.

 

[Another retired guy]

Re: Starting!!

Yes, that's quite possible. Changing the thermostat might be a good starting point. If the engine then warms up you can tell if the choke is working. If the choke works, then you can check/adjust the fuel mixture.
Pull a spark plug - if it's black then mix is too rich.

 

[dotsadie]

Re: Starting!!

Will look at the thermostat tomorrow.PS Does it have to be a marine thermostat?

 

[Another retired guy]

Re: Starting!!

No. An auto thermostat is fine, but it does have to be the right one for that engine.