My guess is the previews owner , He did the same trick to hold them tight together , the old plugs look swollen compering to 1 of the new ones.
also with metal rescue they say its water-base non acid rust removal ( great for gas tank), but if you say it's just a discolor then I guess I don't need to use rust removal anymore
what they saying ......
"• Easy to use, virtually no labor involved (no scrubbing, dipping, brushing or other agitation)
• Just soak the part in a plastic container for 5 mins – 24 hrs depending on the severity of the rust
• SAFE: no acids, no caustics, no health risks, non-toxic, safe on skin
• Environmentally Friendly: Safe for drains or sewer systems (check local laws for compliance)
• Cost Effective: Most efficient, easiest and safest way to remove rust
• Does not compromise any mechanical properties or functionality of metal
• Valued ARMOR brand is a trusted name that means reliability and confidence
• Can be used in conjunction with other ARMOR corrosion inhibiting products
• Product is available for immediate use upon removing from liquid
Assembly of a Japanese bicycle require great peace of mind.
" Zen and the Art of Motorcycle "
1981 Honda cb750 C