Merc 50 Starting Issues

"Hello folks,

Great site w

"Hello folks,

Great site with a wealth of info. I'm having issues with my engine and I wanted to post these questions to see if you can lead me in the right direction to get it resolved. I have a 1996 Marada 21 ft bowrider with a Chevy 5.0 liter, 2 barrel carb and a Apha I (Gen II) outdrive.

Within the last six months, I have replaced the following: spark plugs, spark plug wires, distributor, rotor and the coil. All new parts are Quicksilver marine parts for this engine.

My problems started out (prior to my replacing the parts mentioned above) with the engine cutting out on me and I determined that the coil had gone bad (because of heat). I put a new one on and have approximately 12-15 hours on it and this last weekend, the engine cut out on me again. Last time, I let it cool off and then it would satrt but this time it was dead. Luckily, I was close to shore (West Coast of Florida) and was able to get to shore and get a new one (non marine Accel coil for a Chevy 305). I installed it and the engine turned on on the very next try. QUESTION: Is there anything other than heat that can kill a coil? Mine is mounted right behind the head and seems to start acting up only when we pull the tube (Obrien). We also pull my son skiing and both sons on kneeboards and never had a problem.

The other issue I am currently having is that I took it out the next day and once I got it in the water, I turned it on and let it idle while I finished getting my gear into the boat. About 2 minutes after, it shut down and I have not been able to get it started again. It turns over and sounds like it wants to start but it just doesn't. I suspect its a fuel issue and would like to know if there is anything that I need to look for that can help me resolve this.

Thanks in advance,

RObert"

"I take it this is electronic

"I take it this is electronic ignition. The pick up coil in the distributor can be failing. The ignition module may be getting to hot or the ignition system has bad grounds. Since you are in salt water(if you are in the gulf,west coast FL?)this is where I'd start. Clean all ground terminals in the system and check for corroded wires that could be failing. Wire ends,connectors,junctions etc.
It could be by the time you replaced the coil the module had cooled down enough to work again. Poor grounds can cause all kinds of problems."

"I agree with charli... Its pr

"I agree with charli... Its probably the pick up coil. Not too expensive to fix and on a scale from 1 to 10 its about a 5 as to the level of difficulty to fix yourself. TO CHANGE: 1) pull the dis. cap off and note or mark where the rotor is pointing. Also put a mark on the lip of the distributor and the mounting surface. 2) pull the bolt out that holds the distributor tight. 3) slowly pull up on the distributor while turning it counter clockwise. 4) Remove the sheer pin that is in the gear at the bottob of the distributor.
5) pull up on the gear shaft from the top where the rotor mounts. the pick up coil is under here. 6) replace the pick up coil.

TO INSTALL: Reverse procedures. When installing into engine line the rotor marks up by offsetting the installation and turning in clockwise. Also when reinstalling the gear into the bottom of the shaft, be sure that the slotted center faces down.
Any issues, email me at : [email protected] }"

"Thanks for the info. I will

"Thanks for the info. I will look into it this afternoon but I doubt that I will be able to change out the pick up coil myself. The problem is in the position of the engine wrt the thr transom overhang. The distributor sits about 3-5 inches directly under the overhang and I believe that in order to remove the distributor I would have to remove the engine (or at least release it from the motor mounts and slide it forward to be able to get the clearance. Definitely not a job for me.

I originally thought that it cold have been a fuel issue as to why it won't start now. I am going to try to get it started this afternoon using the "starter spray" that I picked up at the local auto parts store. If this doesn't work, I'll have to take it in to the shop to get it evaluated.

I have another question concerning WOT RPMs. My boat is a Marada 21 ft and dry weight is about 2850. Loaded with gas (45 gallons), gear and 2 people, I estimate total weight around 3700-3800 pounds. I have a stainless steel prop that has a 19 pitch on it (I bought the boat this way). When I am at full throttle, I am pulling around 4800-4900 rpms doing around 40-42 mph. Does this sound like the right numbers or does it appear that the prop is too high in pitch? Water condition is smooth.

Thanks again,

Robert"

"Sounds like its pretty good t

"Sounds like its pretty good to me. What are you trying to acheive? A better hole shot or actual top speed. 19 pitch is pretty good for the boat you have as long as the plane out time is right. If you want a better take off out of the hole the pitch goes down but you lose top speed. For better speed, the pitch goes up and the boat takes forever to get on plane and to top speed but will travel faster. Sounds like your in the middle right now. I would leave it alone
Dave"

"Update on the coil issue. I

"Update on the coil issue. I installed another coil today and the engine turn on with the first try. So the new coil that I installed died on me with about 2-3 hours of run time on it. When I installed the new one, I noticed that I could see the spark inside the distributor cap (the new one installed in April) so I am assuming that this is why the coils have gone bad on me. I will attempt to get the cap replaced under warranty to save a few $$ but I am not holding out hope. I think that the marine mechanic that installed it may hve damaged it when he tightened the screws.

Concerning the RPMS at WOT. I jus wanted to know whether I was within the normal operating range of the engine. I didn't want to be over or under pitched. We generally ski, kneeboard, wake board and tube in terms of use and also try to fish on occasion. 40+ mph on my boat is fast enough for me.

THanks for the help folks.

Robert"

Robert:

Is the rotor in con

Robert:

Is the rotor in contact with the cap? There's some type of spring deal in there that may not be touching.

Jeff