Help! Ignition troubles..

2cycle

Petty Officer 1st Class
Joined
Mar 12, 2004
Messages
234
As the title implies, I am almost at my wit's end.<br />I have a 74 1500 and I recently bought a spark plug wire kit from NAPA and fabricated the wires. After reinspecting and redoing the crimps, I still have arcing at the plug boots and at intermittent points from the cap to the plug ends. Do I need to try and find longer boots or does the size matter? I used dielectric grease in liberality but still have the spark jumping out of the boot to the metal and arcing in other places. Can these wires be saved? I think the crimps are good and each wire snapped onto the plug, so I'm at a loss. Thought I would look for some tighter and longer boots but wanted to check here first. I wanted to avoid $100 + for factory wires, but will do it if I have to. Thanks for any and all advice.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,097
Re: Help! Ignition troubles..

2Cycle, I replaced the wires on my '77 1500 distributer OB with 28 inch wires I bought from www.oldmercs.com. They were $5.95 each (plus shipping) and I reused my old distributor boots and spark plug springs and boots. They seem to work well, without arcing. This was the best price I could find
 

2cycle

Petty Officer 1st Class
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Mar 12, 2004
Messages
234
Re: Help! Ignition troubles..

Chris 1956,<br /> Thanks for the response. When you reused the springs, did you just stick the contact point straight through the insulation and into the wire? I used automotive crimps instead of the springs and had arcs on all of them. I have some of the old springs so I can use them. Also on the cap end, how did you connect to the male threaded end that screw into the cap? Did you just strip the copper stranded wire, fold it back and slip the male end over it before crimping?<br />Also, does your engine purr at idle or do you have a miss? Mine has a miss and it is frustrating me to no end. Is it realistic to get a really smooth idle on these things. Thanks.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,097
Re: Help! Ignition troubles..

2Cycle, The wires come with the threaded end already attached. I bought these because I was afraid I would not be able to make the crimps (myself) waterproof. On the plug end of the wires, I reused the old springs and boots. I stripped 1/4 inch of insulation off the wire, frayed the solid wire core and installed the springs so the prong contacted the core through the insulation and the frayed ends touched the spring. The boots slip on with a little bit of WD-40. I have no arcing. I have yet to complete the breakin of the new powerhead, but it runs smooth, w/o a miss. Good luck
 

2cycle

Petty Officer 1st Class
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Mar 12, 2004
Messages
234
Re: Help! Ignition troubles..

Chris1956,<br /> Thanks for the info and advice. I'll give it a shot. Good luck with the break in.
 

2cycle

Petty Officer 1st Class
Joined
Mar 12, 2004
Messages
234
Re: Help! Ignition troubles..

I ordered the yellow wires and found out that they do offer the springs and boots as well, so I went ahead and ordered. Will update when completed.
 

2cycle

Petty Officer 1st Class
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Mar 12, 2004
Messages
234
Re: Help! Ignition troubles..

To update, I received the yellow wires, boots and springs and promptly assembled them and put them on. It looks like the arcing problem is gone, but the missing at idle and up to 2500 RPM remains. The engine will still open up and run well at WOT, but the miss is enough to make the motor shake--esp. at lower RPMs when idling. Are the rotor buttons on these things pretty bullet proof or would I do well to replace the ditributor (I have a spare) and start over with a new cap? The rotor on the spare looks a little better, but is not perfect. I don't spend a lot of time trolling, but would like to get this problem fixed. Any suggestions would be welcome or sharing of similar experiences on this engine.<br />Thanks.
 

Clams Canino

Commander
Joined
Jan 10, 2004
Messages
2,179
Re: Help! Ignition troubles..

The carbon buttons that go inside the cap are available from Mercury for $4. Clean your cap and run it through the dishwasher.<br /><br />The rotor itself does *not* come off the shaft.<br /><br />-W
 

2cycle

Petty Officer 1st Class
Joined
Mar 12, 2004
Messages
234
Re: Help! Ignition troubles..

Clams,<br /> I noticed that the rotor on the distributor is "eating up" the contact points a little bit in the cap. The cap was replaced at the end of last year and looks worse now than a couple of used ones that I have. I've got a distributor from a 71 135 that seems to have a good looking rotor. Will that match up with the 74 150 ( I'm assuming so?)? I thought about swapping out to see if it makes a difference. Thoughts?
 

Clams Canino

Commander
Joined
Jan 10, 2004
Messages
2,179
Re: Help! Ignition troubles..

Yes they will swap. Set max advance to 21*<br /><br />-W
 
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