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1987 Mercury Classic 50 Starting Problem

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Pcchevyman

New member
Hello All,
I'm new to the forum and looking for some advice. Thanks to all in advance.
I have a 1987 Merc Classic 50, it starts and runs great when cold. It will idle, rev, go into gear, do everything just like normal when cranking it for the first time that day.
I'll run across the lake to my first fishing spot and cut it off for 10-15 minutes.
It's when I try and restart it after fishing my first spot is when I have trouble.
It will turn over and over and over but never fire. I've tried choking it, not choking it, pushing the throttle half way forward with the cold start button pressed, etc.
It kind of seems like it's flooded, but I'm not sure.
If I wait an hour or more it will usually restart and run great until the next time I cut it off.

Any ideas?
Thanks again
 
Pcchevyman said:
Hello All,
I'm new to the forum and looking for some advice. Thanks to all in advance.
I have a 1987 Merc Classic 50, it starts and runs great when cold. It will idle, rev, go into gear, do everything just like normal when cranking it for the first time that day.
I'll run across the lake to my first fishing spot and cut it off for 10-15 minutes.
It's when I try and restart it after fishing my first spot is when I have trouble.
It will turn over and over and over but never fire. I've tried choking it, not choking it, pushing the throttle half way forward with the cold start button pressed, etc.
It kind of seems like it's flooded, but I'm not sure.
If I wait an hour or more it will usually restart and run great until the next time I cut it off.

Any ideas?
Thanks again
Click to expand...

Have you ever tried the primer bulb?

Does the way it runs change at all when it warms up?

For instance how is a dead idle in gear when it's cold versus when it's warmed up?

Jon
 
leaky said:
Have you ever tried the primer bulb?

Does the way it runs change at all when it warms up?

For instance how is a dead idle in gear when it's cold versus when it's warmed up?

Jon
Click to expand...

Thanks. I have not looked at the primer bulb at a time when it couldn't crank. I usually pump it once on a cold start. I'll check that out.

On the initial cold start of the day the engine starts and runs well. It will run well for as long as I leave it running. (At least 15 minutes from my experience)
Once I turn the switch off it will not recrank again for about an hour.
So to answer your question, I'm almost always "cold starting" it because of the hour delay between when it cuts off and when it will start again.
Basically when it will crank and run while "cold", it runs great.
Otherwise it will not crank for at least an hour from the time it was last shut off.
 
The term " crank " can be confusing to some.----------In this case does it mean it will not turn over with the battery or does " crank " mean it will not start.
 
IF the motor is spinning over nicely, I suspect you have a carb flooding problem.

Here's how to find out: Duplicate the way you were running it but, before shutting off, pull the fuel hose off and run the carbs dry. Do NOT pump the bulb until you what to leave. If the problem is gone, it's carbs; if not, start looking at electronic components falling due to heat.

Jeff
 
Racerone, by I crank I mean it won't start. It'll turnover fine, just not start.

fastjeff, The motor is spinning nicely and will do everything except fire and run.
I like your idea of disconnecting the fuel line to see if the carbs are flooding the engine. I'll try that, otherwise I'm gonna take this thing back to the Marina that tuned it up last year. Only thing I hate is a current 2 week turnaround on repairs!!
Jeff, is there any probable electrical components that could behave this way during failure?

Thanks to everyone
 
The switch box is everyone's favorite whipping boy when these things happen, but it could also be bad windings in the low speed coil of the stator.

Let's hope it's the carb(s). Cheap and easy fix.

Jeff
 
Ok well to further confuse you - I'm assuming that may be one of those inline 4 cylinders with the fuel pumps on the carb?

If that is the case the fuel pumps suck, or more accurately the problem is they don't suck very well.

I ran one for a long time and it is/was a great engine with the exception of it almost always needed a prime with the bulb, sometimes even on a plane it would start dying out and a couple pumps would cure it. I messed around with that setup a bunch of times, considered even going to an electric pump, but really it worked fine if you just primed it prior to starting and occasionally when underway.

If someone else had that engine and didn't see the trick I could see them running into all sorts of troubles, cured by hitting the bulb on a regular basis.

Jon
 
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