PLUGS

[jamman18]

Just wanted some advise......is there a certain type of plug I should use on 1977 with around 45,000 miles?  I hear a lot about hot vs cold plugs and am a bit fuzzy on this subject.

[sgtslag]

Hot and Cold plugs refer to their temperature range, the hot/cold refers to their ability to shed heat (don't remember details, don't want to screw it up by saying the wrong explanation -- can be looked up on the Internet:  "spark plug temperature").  Unless you are having problems, use the standard temperature plugs.  

However, if you are going to change out the plugs, I would highly recommend using NGK's Iridium plugs:  they require less energy to create a spark; they almost never misfire; they make the engine run smoother, start easier, and they will last for at least 50k miles, if they do not foul because of bad carbs, or piston rings.  They are about $8 per plug.  My bike starts amazingly fast, compared to the old, regular plugs, seems to run smoother/better, according to my butt-dyno.  Cheers!

[Re-run]

The d8ea plug is standard. The d7ea is a hotter plug and the d9ea is a colder plug.
If you go with the iridium, the number is dr8eix if I remember correctly.

[jamman18]

so if I do have some fouling from a bit of oil is it still worth the extra for ngk?

[sgtslag]

Not really.  If you have an oil leak (bad rings?), the expensive plugs will foul, and be ruined.  Better to throw away cheap (NGK) plugs, rather than expensive ones.  Don't  buy the cheapest you can get, as poor plugs will have you chasing your tail to resolve "problems"...  Get the fouling issue resolved, then spring for the Iridium's.  Cheers!

[Re-run]

For the time being, the d7 plugs will help burn through the oil till you get things fixed.

[LukeM]

Hot vs. cold?  Refer to THIS LINK.

Looks pretty good to me.  I'd say start with the middle ground, then move up or down from there.  If you're experimenting, I wouldn't spend the money on the iridium plugs until you know what you've got and how it's running.

But that's just me: Mr. Cheapo.
Luke M