spark plug gap

[65eglide]

I bought some new H-D plugs for the 65, the H-D shop said these should be gapped at .40 ,but the service manual say's between .025-.30, it seems to start and run fine with .40, should I re-gap these to what's in the service manual. I had always thought the .40 are better with and electronic ignition rather than the standard points ?. not sure if the technology in contructing plugs is that they should be run at a wider gap now than in the 60's

[Magic]

Hello, "If is isn't broke don't fix it" As you know smaller gap would foul out quicker especially during cold starting conditions or even excessive low rpm running...and a larger gap like 35-40 would produce a better spark for ignition purposes and overall performance. Check your plugs after a few runs and look for the light chocolate coating on the insulater, that'll tell you everything is fine. Heat range of a spark plug is most important to the style of riding. Just my 2 cents (-: Merlin in Pa. Keep Ridin em.

[65eglide]

I feel the same way, it seems to be running fine ,just had to change the voltage regulator. starter sounded like a old man groaning to get up. but now it's charging at a rate that's fine.

[portagepan]

I run the Autolite "fine wire" plugs on my 1965 FLH. I couldn't believe it when I put them on. It was like a tune up. They are supposedly designed for the lower output of older ignitions. Of course, they are platinum. Their number is MP4275. I run .032 gap. I think Bosch makes something like them, too.
Mike

[65eglide]

Originally posted by portagepan
I run the Autolite "fine wire" plugs on my 1965 FLH. I couldn't believe it when I put them on. It was like a tune up. They are supposedly designed for the lower output of older ignitions. Of course, they are platinum. Their number is MP4275. I run .032 gap. I think Bosch makes something like them, too.
Mike

maybe I'll try then next time ..

[T. Cotten]

Magic posted: "Check your plugs after a few runs and look for the light chocolate coating on the insulater, that'll tell you everything is fine."

Where are you buying your gas, Magic?

It must be noted that many, if not most, modern US fuels no longer 'color' plugs in the time-honored manner, due to federally mandated anti-deposit additives. You can burn very rich and still have a light gray insulator; A perfect mixture can now look frighteningly lean.

...Cotten

[Magic]

Additives such as Lead, Marvel mystery, Stabilizer, They run great whenever, Guess I shouldn't give out info without checking first with others...Plug checking is essential in performance and engine condition..that hasn't changed yet has it? Keep ridin them..Merlin in Pa.

[LouieMCman]

I can't believe anyone would take the advise of a harley dealer that won't work on anything older than an EVO. The manual says .025-.030, I have ran .028 with no problems for the last 25 year. But hey what do I know....call the Harley shop. Just my two cents after a few beers.