1979 115 Merc trouble starting

[bassFISHIN]

I just bought a 79 ranger bass boat with a 115 merc on it. When I bought it the previous owner started it right up for me. I took it to the water and just can't seem to get it to turn over. I was able to get it to turn over just once after multiple attempts but it bogged down. After a bunch more attempts, the battery was drained. I don't know what im doing wrong but it is very frustrating! I don't know much about the mechanics so any help would be greatly appreciated!

 

[Chris1956]

Re: 1979 115 Merc trouble starting

OK, It sounds like it cranks, but doesn't fire. If so, make sure you are choking it well. Pump the fuel primer bulb until it is hard. Pull up the cold start lever all the way. Make sure the motor is trimmed all the way down. Make sure you hear a click when you push the choke button. Hold the choke button down while cranking to motor. It should start after 30 seconds or so. Keep choking it until it starts to run, they are hard to flood.

If all else fails, spray some premixed fuel into the carb throats, hold the choke button down and crank it up! Now if it doesn't start, you will need to trouble shoot the ignition.

 

[freefall101]

Re: 1979 115 Merc trouble starting

to save starting a new thread about the same sort of issue i would like to ask a follow up question.

I have the same engine i think. 1979 in line 6 cyl blueband 115 engine.
I have had the same problem as listed above, The problem seems to be teasing me though. At first the engine exhibited all the symptoms as above but would start after a lot of hard work. I have replaced the carbs as the existing ones werent able to be stripped, Screw heads broken etc. I was hoping that this would be the end of my woes but now i find i have no spark at the plugs. Where do i start now and also what other things could i do to help set up the new carbs and ensure a slightly healthier start.

Many thanks to all that may take the time to read this................

 

[Barnacle_Bill]

Re: 1979 115 Merc trouble starting

Check you battery cables. They must be very clean and tight. Have your battery load tested.

 

[Chris1956]

Re: 1979 115 Merc trouble starting

Freefall, Get on the CDI Web site and look up the troubleshooting procedure for your Merc ADI Ignition. It will walk you thru testing of the kill circuit, switchboxes, stator, coils and trigger.

 

[bassFISHIN]

Re: 1979 115 Merc trouble starting

So I got the boat started, thanks Chris. It wouldn't however start in neutral it would only start when the throttle was not in gear going forward. However now my problem has moved. I can get the engine to rev quite easily but when I move the throttle back to neutral to put it into gear, the engine bogs down. This happens every time. After working it hard enough I was able to put the motor into gear, this took some work though after a number of starts followed by bogging down. When the boat was in gear I was able to putz around the lake until I would try accelerate. Any time the throttle was full tilt or slow to idle speed, it would bog down almost as if fuel was not being delivered at these speeds. This boat had not been used much last year as it sat stagnant in the previous owners yard. If anyone has an idea of what my problem could be or has any insight of how I might remedy this so I can get out on some of these spawning fish, I would greatly appreciate it!

 

[Chris1956]

Re: 1979 115 Merc trouble starting

OK - It sounds like it will only start when the cold start lever is up, and the motor is in neutral. When you put the cold start lever down, the motor stalls. If this is the case, either your idle speed is too low, the carbs are dirty or the idle mixture is misadjusted.

Idle speed should be < 1000RPM with cold start lever down, in neutral. if it will not idle at this speed, either the idle mixture is off or the carbs are dirty. It probably makes sense to clean the carbs, set the floats and install new inlet needles and gaskets. Get a service manual, if you do not have one.