Trying to get the boat ready for the water. Gonna get some new tires for trailer and such, but tried to crank it to change oil and will not start. No spark at plugs so went further back, no spark from coil either. Has power to it...had this problem last year and i gave up....I am not giving up this time, need some experienced help. It is a 1984 Cheetah 166 with a mercruiser 140. Has the old points and condenser distributor. Was gonna order a points set,condenser,coil, and wire set. Cap and rotor looks new. Please help...I want to ski this year!!

If you have power to the coil, the problem lies either in the coil itself or within the distributor. You can troubleshoot a coil problem by simply trying another coil. (A note here, coils can be "fried" by leaving the ignition key in the "on" position for long periods of time).

If the coil isn't the problem, some things that can be wrong on the distributor side:

A bad condenser can cause a no-spark..Are the points actually opening & closing? Several reasons they might not be...

Changing out the points, rotor and condenser and getting them set correctly should fix any of the above problems. But one more thing to check---There's a short ground wire within the distributor connected from the plate the points mount to, to the body of the distributor. This wire flexes when the distributor advances the timing. Sometimes they come loose or break, and if it's not connected, the points can't tell the coil to fire...

I used to have this problem almost every year with my MerCruiser 140. Clean up all the connections in the distributor, and it should fire right up. You do however, have to remember to put the rotor back in..

Remember, the basic circuit is the points/condenser supply voltage to the coil primary side, the two screws on the outside shoulders. Make sure the ground wire on the coil is connected to a good, clean surface.

Also some ignition circuits used a resistor in series to the primary side of the coil. I can't remember if the resistor was used only during the starting or only during the running of the engine, I think only during the running. If this resistor is open (if used) this will cause you to loose the primary.

thanks for the info guys...will check all the connections later today. Also gonna go ahead and order a new coil, condenser, and points set. How do you set the points....first time for me to try this,,,, got tired of all the ripoffs around here(LONG story)

Cam has to be at TDC I believe it is, then with a feeler gauge you set the distance to spec.

I'll fire you a PM with a price for all those parts.

Any high point on the rotor shaft cam will do.

With the points open on the high point, adjust the gap with a feeler gauge and usually a screwdriver on an adjusting/securing screw

I would check thoe connections and swap out that coil first.

PH has a point on some ignition systems using a ballast resistor and ballast type coil...

checked all my connections and cleaned them up....still no spark. So i opted for the pertronix conversion to electronic ignition with a coil to match. No more points! F14bombcat, those are awesome prices...the shops around here wanted $53 just for the coil....thats what I was referring to earlier(ripoffs). Also bookmarked your site, will be using u in the near future!!

Well there ya go, just replace the old bad stuff with new good stuff!


Let us know how it goes!

Anytime you can get away from points and go pickup coil type you did yourself a favor.