spark plug wire arcing on 1500

[2cycle]

Greetings,<br />I replaced the spark plug wires on my 74 1500 and noticed when running the motor at night that there is some arcing from several of the wires behind the throttle control lever on the motor and then occasionally from wire to wire as they feed into the distributor cap. How or why is the spark arcing through new insulated wires and does anyone have any suggestions to eliminate this ? Is this common with Thunderbolt ignition? Thanks for the help and advice.

 

[ZmOz]

Re: spark plug wire arcing on 1500

Are the wires making contact with the areas they should be? They shouldn't be arcing even if there was no insulation if they are connected properly.

 

[2cycle]

Re: spark plug wire arcing on 1500

ZmOz,<br /> The wires run through the bracket behind the throttle arm and it does seem pretty tight in there and # 5 and # 6 are pretty close to touching the arm. I don"t think there are any problems with the connections to my knowledge. In general whar causes an arc? Thanks>

 

[rickdb1boat]

Re: spark plug wire arcing on 1500

Are they solid copper core wires or automotive wires(Carbon core)?

 

[Chris1956]

Re: spark plug wire arcing on 1500

2Cycle, Are the wires in good condition? If they are like the ones from my '77 1500 Merc, you should replace them. I was able to buy 28 inch long yellow Merc replacement spark plug leads for about $6 each without boots or connectors from www.oldmercs.com, best price I could find.<br /><br />Part number 84-63212A 2

 

[2cycle]

Re: spark plug wire arcing on 1500

The wires are copper and were fabricated from a Sierra kit that had 25 ft. of wire and the threaded male connectors for the distributor cap. The kit was $29.99. I had to buy the boots and spark plug connectors from NAPA. The crimps all seemed tight. I was just surprised/perplexed to see arcing at night when I finished. I read some past posts and someone said that the TBolt ignition was very hot and could easily jump an inch or more from insulated wires. Can anyone corroborate this and any suggestions on where to go from here? Thanks for all the responses and help.