Hey guys...

at a loss here, have an 82 honda 110 that my daughter uses. I rebuilt the engine, got a cdi and coil off e-bay (all tested and in specs). Bike runs fine but after a few months the plug starts firing off all over the sides then the bike runs rough then finally won't start. By side I mean when I take it out and test it by putting it on metal, it spark to the left and right of the tang, I don't get a strong central spark. Three plugs have done this so far and they all look fine when they are pulled, gap is properly set.

Put in new plug and it runs great again. Never seen this problem before!!! Not a big deal, I can keep putting plugs in (they are cheap) but just wondering if anyone knows the cause of this.

 

The CDI has a VERY strong charge vs a regular coil. Using the 'regular' large flat type electrodes is probably causing some type of 'oxidation' on the electrodes that is causing a lot of resistance. 'Prove' it to yourself by taking an old misfiring plug and filing the center and outer electrodes and retest firing. 'If' this restores the proper firing of the plug - then that is what the problem is /was. 'If' you can find them for an ATV - the 'pointy' double platinum plugs might last longer.

"Or" - might be some strange 'additive' in the brand gas that you are using.

"Or" - might try changing to 'one step colder' spark plug; the original plug was spec'ed on the coil - the CDI is a hotter spark.

 

I have noticed the Gas we get now is crap at best
I have also noticed different regions have different blends of gas you could have an Alcahol blend causing lean conditions
what color is the plug when removed
My bet is engine is probably lean
I have two 82 110s had to rejet both
Also found consistant fuel in racing gas and mix 50/50 with premium I also get the racing gas with Lead as these like lead
Acolder plug may help
Good luck
Ray

 

Thanks for the replies guys. Plug looks normal when removed, just a tad wet (because by then it's not starting) but nothing too bad. Don't think it's a gas problem, no additives here that I can see but you never know. I'll try filing down an old plug and see what happens. I may just try a higher octane fuel too.

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