No fire

[ChevyReb]

1987 Mercruser 165 I/O 4cyl, Carb and points. Boat is an Invader bow rider. Engine has not been run in three years.<br /><br />Getting no spark at plugs and also do not see any arc accross the points. Have 12v at coil and points. Wires ohm out good. Getting gas into cylinders.<br /><br />This boat does not appear to have a kill switch!<br /><br />I have tried three different coils but still no fire. What do I need to check or replace next?<br /><br />Any suggestions to get fire to this engine. Should I try a new set of points and condenser?<br /><br />Thanks,<br /><br />ChevyReb

 

[rattana]

Re: No fire

I would get new points, rotor, plugs after three years sitting.<br />Do the points open and close when cranking?<br />What is the point gap when they are riding on the cam?<br />Is the shifter in neutral, is the neutral cutout switch working?<br />Just a few ideas.

 

[ChevyReb]

Re: No fire

Thanks rattana,<br /><br />I thought that it would be a good idea to get the parts you suggested too, as well as new wires. <br /><br />I am not sure how to test the neutral cutout switch. We did try ti start it in neutral as well as with the throttle in the faster position, without the drive enguaged.<br /><br />We don't seem to be getting any arc off of the coil wire either. I guess the next step would be new points and plugs and all.<br /><br />BTW, what gap should the points be set too???

 

[rattana]

Re: No fire

I don't have specs for your boat but it should be between .019" -.021". You should get fire with that gap. Also run a small file or sandpaper between the points (with ignition off)in case there is a glaze on the points.<br />You can temporarily disconnect the wires off the negative side of the coil, leave the one going to the distributor connected. This will remove the tach signal and the cutout switch so you can test it.<br />Don't leave the cutout switch disconnected or you can damage your stern drive, when shifting into gear without it.<br />Start in neutral

 

[Don S]

Re: No fire

The neutral safety switch keeps the starter from cranking the engine, not preventing spark.<br /><br />Points are probably the problem after setting used for several years.<br /><br />Which distributor do you have, the original Delco or the Prestolite.<br />If the distributor was ever replaced, Merc started using the prestolite and the gap, dwell and timing changed.

 

[ChevyReb]

Re: No fire

Re-gapped points to .19 and could see arc at points. Replaced cap and button and she fired right up! <br /><br />Thanks guys!!!<br /><br />I did find another issue though. There is a water reservoir that is cylinder shaped on the lower port side of the engine, about 5 inches in diameter and as long as the length of the engine. It has a lot of hoses connected to it that go to the water pump, exhaust manifold and various other places. There is a bolt in the middle front that holds a round plate on it with a rubber gasket. This thing is leaking badly in the rear and running a steady stream out of the plug hole! It is difficult to see back there because of all the hoses and the back of the engine is under the rear deck of the boat. It looks like two large U-bolts hold it in.<br />Now here are a few questions…<br />What is this thing called and what is its function? Is the rear of it like the front and just the gasket is probably leaking? <br /><br />This boat has the small seats on each side of the engine cover in the back of the boat and the fuel tank is under the seat on the port side right beside this cylinder…looks like a real PITA to get at and repair. About how much would a boat shop charge to repair this and replace all of the hoses too? This is a neighbor’s boat. I can help him put on new points, plugs and dist cap and wires, but I don’t have a lot of time to help him with fixing the water leak right now as it looks to be a few hours to do that job. And I don’t want him to get ripped off by a repair shop…So I am looking to get some ballpark figures.<br /><br />Thanks again,

 

[Don S]

Re: No fire

That's the heat exchanger. Here is a link to your engine with the Merc parts break down.<br /><br /> Merc Parts <br />Just click on the 165/3.7L link

 

[rattana]

Re: No fire

Yes both ends look the same. The end plates are made of brass, and they can bow outwards if too much pressure is exerted on them. (Frozen water!!) If they are not damaged you can remove the end plates and use a rubber mallet to shape them to get them to seal again. A couple of hits near the center hole should work. Replace gaskets, etc.<br />Easy with the hammer

 

[jeff13601]

Re: No fire

I had the same problem and I removed the grey wire on the negative side of the coil and everything was good after that. Also I do not believe that you should have 12 volts at the points. Check and see if the power wire coming to the positive side of coil from the starter solonoid is about 8 volts. There should also be a purple resistor wire at the positive side of the coil.