Engine Misfiring (86 Minx)

[jodynich]

Our Minx is just a little "off." When I ran it the other day I noticed it was missing at mid to high rpm's. The odd part was that it sounded smooth as silk when out of gear and just revving. I have 0 knowledge of engines so I was wondering if you guys might be able to diagnose the problem (may be a generic problem). My noob guess is the spark plugs but before I change them I'd like to get a second opinion. The misfiring isn't bad either but its just enough to be noticeable.

Thanks for your help.

[DonziJon]

I have an '86 Minx as well. Start up the engine After Dark in a dark place and open the hatch and see if you see a little "Light Show'...spark plug wires arcing (old insulation leaking) every which way. If so, replace the wires.

While you're at it, replace the plugs as well. If that doesn't fix the "misfiring", pull off the Distributor Cap and see if the terminals are clean inside the cap. ..no crusty buildup on the posts. If there's a buildup, you can tempoarily scape them clean.. or replace the cap. You NEED a "Marine" distributor cap. Automobile caps are dangerous because they could cause an explosion which marine caps are designed to prevent. John

[gcarter]

Hi Jody.
Do I have your boat in my Minx hull # list?
http://www.donzi.net/forums/showthread.php?t=39260
If not, send me your name and state, and I'll add it.

[MOP]

Most all misses are ignition, wire are the biggest culprit! Do it all plugs, cap, rotor & wires, buy a good set of wires standard stuff does not stand up to long for marine use.

[Cuda]

It most likely is in the ignition, but how old is the fuel? Have you dumped the water separator lately? Both of them will cause the same effect.

[BigGrizzly]

My bet is plugs.