Spark plug change interval (86-87)

Does anyone know why the factory manual states to replace the spark plugs every 4000 miles? I usually think of plugs as something that lasts a long time. There are notes that mention 86-87 model years only. What is unique about these engines that require such frequent replacement?

I've had my current plugs in for almost 12,000 miles. I pulled them and they look good to me.

 

Pull them every year to inspect and so they don't become stuck in the heads. If they look good, I'd put them back. My '82 Sabre has had the same plugs in it since 1989!! 35,000 miles!! They still look fine.

 

Misprint or bad translation from Japanese numerals.

SMALLER plugs on newer models require far more frequent replacement than on '86/'87, so maybe refering to that??

 

I thought the exact same thing. Trouble is the Clymer manual says the same thing.

 

Clymer usually just copies, so if factory manual is wrong the same error will be in Clymers too.

 

Trouble is they denote "86-87" model years only. Implying that other years have standard change intervals.

 

I just looked at my OFFICIAL Honda Service Manual and was SURPRIZED to see that it calls for replacement, as you state, at 4000 mile intervals!! Makes no sense to me either.....

I have found a couple of small, uncorrected errors in the manual previously, but not like this!

 

You're right. Clymer would never stray far from the factory.

 

I've owned several '86 - '87 vfr's and have never had to replace plugs any sooner than 15k miles. Even then they looked fine and were within spec on gap. BTW, be sure to put an anti sieze coating on the threads when installing and don't overtorque them.