When to change spark plug?

DonnnN · #1 (**permalink**) 10-08-2009, 04:27 AM

Hello everyone, I was just wondering.. After how long do you change your spark plug?

And what problems with the bike will point to a new spark plug?

btw i am riding a 80cc chinese engine.

Thanks

**BarelyAWake** · #2 (**permalink**) 10-08-2009, 04:38 AM

A worn electrode can happen eventually, but most people change plugs during a "tune up" - not specifically just these HT engines but a common practice. You can clean a plug if there is heavy deposits, there's even a lil tiny sandblaster unit made for this ($10) but I just get a new plug if it's that gooped up;

- Harbor Freight Tools - Quality Tools at the Lowest Prices

Many 2 strokers (snowmobiles, ultralights etc.) usually start the season with a extensive tune up and a nice shiny new plug

Sorry I can't give you a definitive answer like mileage, but usage and things like mix ratios varies so wildly that each one is a lil different lol

linnix13 · #3 (**permalink**) 10-08-2009, 05:10 PM

i ran over 4000kms on my plug, never had a problem, once in a while i will soak it in gas to let it clean itself up

**2door** · #4 (**permalink**) 10-08-2009, 11:51 PM

I've read where the plug manufacturers warn against cleaning plugs. I think that is simply marketing. I've used the sand blast method and solvents and never had a problem. If the electrodes are not burned away, rare, and the porcelain isolator is in good shape, I can see no reason why cleaning a plug will not lengthen the life. After all, it isn't rocket science. Just metal and porcelain. If there is no shorting to ground a cleaned plug should be as good as a new one. But that's just me.
Tom

linnix13 · #5 (**permalink**) 10-09-2009, 08:19 AM

just watch the gap, ive had a spark plug in an older engine a few years ago and the plugs gap kept getting smaller, i would re gap it once a week, turns out the metal was fatiguing from being regaped so much, the electrode broke of and fell into the engine, that was the end of that 2 stroke! so as a general rule, re gap when it needs it, and if you find yourself re gaping it often(more than 3 times) i would get a new plug,

**Bikeguy Joe** · #6 (**permalink**) 10-09-2009, 08:46 AM

Plugs do "wear out" but it takers a long time. The electrodes become rounded.

Clean your plug with a thin knife if there are deposits, (oily) or some 220 sandpaper (dry deposits) when or if you notice harder starting or lower performance.

You should have a look at the plug once in awhile to keep tabs on what's going on with your engine anyway, so that would be a good time to clean or replace the plug.