Sluggish performance first time out - found oil in top of coil

[sleeper]

Went out for the first time today, boat ran great on the muffs in the driveway beforehand. The overall performance was very sluggish. Poor hole-shot, poor acceleration, and I tried a WOT run one time, never saw over 4000rpm when usually with this crusing prop I will see 4400-4500rpm. It even backfired a few times which never happens. I have done all my normal maintenance routine this year. New plugs last year, new distributor cap and rotor this year. New fuel filter every year, new tank of fuel, etc. boat is in like new condition.

From searching, it seems my coil is bad if it is leaking oil. Would this be the cause of the sluggish performance also?


Pic of coil with oil in the top.



which coil is best, OEM coil, sierra cheap replacement, or an aftermarket epoxy filled one like the MSD blaster that doesn't have oil?

Thanks.

 

[Robert D]

Re: Sluggish performance first time out - found oil in top of coil

Yes. My coil overheated and leaked oil, roasted an ignition wire.....leading to various intermittent running issues. Occasional stalling, down on power, etc.

Which is best? You'll get 1000 opinions. I wouldn't waste the money on an MSD Blaster, unless you're squeezing an extra 200 hp out of your motor with various performance add-on's. OEM or Sierra is fine. Locally for me, they run about $49 at a boat shop nearby. And keep the connections clean. The 2 nuts on the top? Clean and inspect them, and the ring terminals on the wire ends, every year. Some emery cloth or fine sandpaper will polish them up nicely. A small brass wire brush, the size of a toothbrush, works great to clean the threaded studs if they get bad. Works great on starter, alternator and solenoid terminals as well. Clean electrical connections are happy electrical connections.

By the way, here's what an overheating and leaking-oil-coil did to my 12v supply wire to the coil:

 

[achris]

Re: Sluggish performance first time out - found oil in top of coil

...From searching, it seems my coil is bad if it is leaking oil. Would this be the cause of the sluggish performance also?

which coil is best, OEM coil, sierra cheap replacement, or an aftermarket epoxy filled one like the MSD blaster that doesn't have oil?

Thanks.

Most definitely. I had exactly the same problem on my old 4.3LX.. Backfiring, not making revs, slow acc. Mine was a corrosion hole on the bottom of the coil and the oil leaked out, but the same effect.

Replace it with a high quality auto coil, like the Bosch GT40..

Chris......

 

[sleeper]

Re: Sluggish performance first time out - found oil in top of coil

At the lake with a new coil. Still the same symptoms. Low on power at all rpms. Only thing I changed over the winter was the cap and rotor and fuel filter that are engine related. Now a new coil.

 

[Bondo]

Re: Sluggish performance first time out - found oil in top of coil

At the lake with a new coil. Still the same symptoms. Low on power at all rpms. Only thing I changed over the winter was the cap and rotor and fuel filter that are engine related. Now a new coil.

The overall performance was very sluggish. Poor hole-shot, poor acceleration, and I tried a WOT run one time, never saw over 4000rpm when usually with this crusing prop I will see 4400-4500rpm. It even backfired a few times which never happens.

Ayuh,.... That says Fuel Delivery to Me,....

Is the tank deliverin',..??
Is the pump, pumpin',..??
Is the Carb fulla Crud,..??

 

[sleeper]

Re: Sluggish performance first time out - found oil in top of coil

I found the distributor a little loose. I advanced the timing, seems to fix the power issue. It makes my idle rpm a little high, but runs much better. I need to set the timing and lock it down, see if it was the whole problem. I never moved it though, which is odd.

 

[achris]

Re: Sluggish performance first time out - found oil in top of coil

If the hold-down clamp was loose and you replaced the cap and rotor, you moved it... Yes, you need a timing light to set it back to the correct timing. And you'll need to set the ignition module in 'base timing' mode.

What is your engine serial number and I'll find the right procedure and post it up for you...

 

[sleeper]

Re: Sluggish performance first time out - found oil in top of coil

Thanks. I hope you are right. It is running great right now. I have the shop manual at home with the right procedure. Thanks.

 

[achris]

Re: Sluggish performance first time out - found oil in top of coil

Thanks. I hope you are right. It is running great right now. I have the shop manual at home with the right procedure. Thanks.

Define... If it has the word 'seloc' or 'clymer' on it, toss it in the trash....

Chris........

 

[sleeper]

Re: Sluggish performance first time out - found oil in top of coil

Lol. No, I have the mercruiser manuals on .pdf on my computer.

Double check me. My engine serial number is 1A063979, I am using manual #25 for the thunderbolt V distributor ignition timing. Thanks.

Define... If it has the word 'seloc' or 'clymer' on it, toss it in the trash....

Chris........

 

[achris]

Re: Sluggish performance first time out - found oil in top of coil

That's the last manual to have a TB-V procedure in it as far as I'm aware. So, for that, yes you have the right manual. For other information you need a combination of manual #32, 37 and 41.. :facepalm: Yeah, Mercruiser did a number with those TKS carbies...

Chris.....

 

[sleeper]

Re: Sluggish performance first time out - found oil in top of coil

Got the timing set tonight and locked down. It wasn't too hard to do. Took the boat out to test at the lake, and it runs great. Either my coil has been failing for a while or the timing has been off since the dealer replaced my engine under warranty when it was new. My top end is better than it has ever been, I hit a new best top speed and a couple hundred more rpm with this cruising prop than ever before.
Thanks for the help.

 

[achris]

Re: Sluggish performance first time out - found oil in top of coil

... the timing has been off since the dealer replaced my engine under warranty when it was new. .....

:facepalm: :facepalm: :facepalm: :facepalm:

This is the most likely answer. The warranty rate (about half the retail rate) and the hours Merc allow for warranty work (about half what it really takes) is terrible. He most likely just threw it in as fast as he could, confirmed it would run, and pushed it out the door.....

Chris......