OX66 - Spark Plug Caps

[TomS]

Engine is 1999 Yamaha SX200TXRX.

Finally figured out how to get at my spark plug caps today to check the resistance. Found one that was definitely bad (infinite resistance) and a couple that may have had some corrosion in the cap and it was hard to get a decent reading.

So what effect do bad caps have on the way the motor runs? What side-effects would you expect to see from a motor with at least one bad spark plug cap? I went back and searched the archives, everyone always recommends checking them, but not much info on specifically how they will effect the engine.

Thanks!

-- Tom

 

[bigbrownbuku]

Re: OX66 - Spark Plug Caps

every spark delivery system has a maximum capability.
increased cap resistance could mean no spark at peak load. a bad time to lose a spark.

 

[ghind]

Re: OX66 - Spark Plug Caps

Tom

My Vmax 150 trp carb had a problem 5 years ago. After 1 minute pulling two barefooters it would drop 400rpm. Huge loss of pulling power.

My caps were supposed to be about 6k, one was about 12k ohms. Replaced them all and it has been perfect since.

Your results sound terrible. Replace them all!

 

[TomS]

Re: OX66 - Spark Plug Caps

Thanks for the input guys, looks like I need to order up a new set of caps.

-- Tom