93? 150hp Johnson fail to run

[Mowens]

the plug wires I bought. But when I test them with the multimeter today most of them stayed at a one on the multimeter like it never got connected and two of them went into the 1700 + range. I'm inclined to think there's something wrong with these plug wires

 

[oldboat1]

guessing it's likely the clips. You need solid core wire, not automotive type wires. The clips on the ends have to make solid contact with the wire core, either with the spike or folded under the wrap-around, depending on what type of connecter you have.

 

[racerone]

If spark can jump a gap of up to 1/2" why does there have to be solid " contact " with the spring thingy in the boot ?

 

[Faztbullet]

.First, the spark plug wires have to be the Gray inductive resistor wires – these are NOT automotive wires. Secondly, the spark plugs should be the factory recommended QL78YC. Use of other spark plugs or wires can cause problems inside the power pack from RFI and MFI noise.The Gray inductive spark plug wires replaced the Black copper spark plug wires that were used on the early 1990’s engines. Doubt your missing o-rings ..likely to look like a silicon gasket. RTV need not be be cleaned from all the holes as on proper reassembly you will fill them back up with RTV ...

 

[oldboat1]

There you go, Mowens. Still recommend testing each wire for continuity, end to end.

 

[oldboat1]

If spark can jump a gap of up to 1/2" why does there have to be solid " contact " with the spring thingy in the boot ?

You’ve raised that before, Racer. I believe that any short in the wired connection would at best reduce the energy available at the plug. At worst, heat generated by the considerable voltage might burn through the casing at the point of the short. Maybe other listers have a better informed response.

 

[racerone]

Poor contact or a bit of rust on the spring thingy will NOT prevent a motor from starting !----What do you mean in the above post by ---" a short in the wired connection "----Explain what you mean by a " short " here.

 

[oldboat1]

break in connection.

 

[racerone]

A---" short circuit "--- is a direct path to ground and it is not a " break in connection "-----A short circuit results in high current , and a fuse should protect the circuit.

 

[Crosbyman]

If spark can jump a gap of up to 1/2" why does there have to be solid " contact " with the spring thingy in the boot ?

I agree that jumping .5 inch should allow the HV to jumps across an oxydized pin then over to the plug...yet I have encountered this issue and the cure was to trim the wire a bit and repunch the pin dead center into the metallic wire.

the HV can't jump across a resistive point if it exceeds its capacity " to jump"

Case in point , HV does not " jump" across the thin lining of the HV cable because of its insulation capacity. I suspect that an oxidized. coating on a misaligned pin

has the same effect…..​

preventing the plug from firing

In my case, it certainly did. scapping & repunching the pin solved the problem .

" Our's is not to reason why our's is to do or row back to shore" same issue with a break in a bend

 

[Mowens]

guessing it's likely the clips. You need solid core wire, not automotive type wires. The clips on the ends have to make solid contact with the wire core, either with the spike or folded under the wrap-around, depending on what type of connecter you have.

I ordered these as they listed as suitable replacement for OEM but I am guessing they are just crap. I ordered new CDI brand ones today. I am using the recommended plugs.

And I did test each wire i got either 1700+ on the multimeter or it flashed around numbers for a moment and settled at the 1 like it was open.

 

[Mowens]

.First, the spark plug wires have to be the Gray inductive resistor wires – these are NOT automotive wires. Secondly, the spark plugs should be the factory recommended QL78YC. Use of other spark plugs or wires can cause problems inside the power pack from RFI and MFI noise.The Gray inductive spark plug wires replaced the Black copper spark plug wires that were used on the early 1990’s engines. Doubt your missing o-rings ..likely to look like a silicon gasket. RTV need not be be cleaned from all the holes as on proper reassembly you will fill them back up with RTV ...

Thanks for the info on the RTV. I will refill the empty holes then. Surprising to fill them. The manual only mentions a thin layer of sealant around the edge inside the bolt holes.

I just cleaned the head faces with acetone but they still like kinda crappy. Can I do a very fine sanding on them?

 

[oldboat1]

Sure can. Wet/dry sandpaper on a flat surface, maybe 150 or 200 grit. Wet the back so it stays in place.

 

[Mowens]

Alright sanded them, new o-rings, RTV, etc.

Put all back together and the compression test all came back right at 90 psi across all the cylinders. I find it odd that some are lower then previous and others are higher. I don't know if that's the crappy HF gauge or what. But they are all reading the same now.

Now new plug wires and still not really getting spark.
This has the optical ignition system.

I tried the spark tester on cylinder 1 and 2 and at the coil I had no spark to 1 but spark to 2. I suppose I need to remove and test all the coils and the pack.

The manual calls for a peak reading voltmeter and Stevens load adapter. I have a regular multi-meter. I can do the coil resistance test but not sure how to test the power pack. Any advice would be appreciated.

 

[Mowens]

So still having issues here. Spark is very sketchy. I tested the power pack using a load tester and dva for the primary lines and got 0 voltage on port side and 10v on starboard. Assuming this means my power pack is shot. Is there anything else that could cause this? Any other recommendations for testing?

 

[racerone]

Shift interrupt switch ?

 

[Mowens]

Possible but if I have disconnected the red plug and cut thr black/yellow kill wire. Would that still hold true?

aggravating chased fuel / compression / and now spark lol.