Spark plug cap

Message

beerbaron · Mon Oct 31, 2005 10:46 am

Hi, I jsut replaced all of my spark plug cap because I tough they were faulty. I tested em around 10 000 ohm.

But then, when I bought the replacement spark plug cap, there seems there is two types. Some have a 5000 ohm terminal resistor and some had no terminal resistor.

What's the proper thing to do here... should I have 4 spark plugs cap with 4 terminals, 4 without terminal or a mix of both.

My bike is a yamaha FZ600, for the fire it uses two pairs of coils.

I'm asking this because I'm still searching for a intermitent loss of power that I think is cause by misfire.

Thanks
BeerBaron

ronboskz650sr · Mon Oct 31, 2005 2:54 pm

When you tested them, what did each cap read? 5K is what I put on mine to get the correct total secondary resistance my coils are supposed to have. Did you measure each cap, or the wires from cap to cap? What does the book say? Questions, questions. I'm guessing the 5ks are the ones, but I could be wrong.

beerbaron · #3 Unread post by **beerbaron** » Mon Oct 31, 2005 3:24 pm

When you tested them, what did each cap read?

The old caps were around 10k-12k, the new ones have 2x5k and 2x0k . They are of different shapes.

Did you measure each cap, or the wires from cap to cap?

Both, with the old caps both secondary resistance were around 30k. And my manual was saying secondary coil resistance should be around 10-15k.

Wires from cap to cap were 13k, which would fit perfectly in the manual specification.

There you go, hope that helps you solve thid question

BeerBaron

ronboskz650sr · Mon Oct 31, 2005 6:08 pm

Interesting. Does the manual say anything about the combined resistance of both caps and the coil secondary? I've heard it makes no difference whatsoever. I guess the only real reason for resistors is to reduce interference in radio devices. Caps are cheap...try it both ways and see if there's any performance difference.

beerbaron · #5 Unread post by **beerbaron** » Tue Nov 01, 2005 5:46 am

Didn't know it was for radio interference.

Thanks
BeerBaron

ronboskz650sr · Tue Nov 01, 2005 8:19 am

I know one thing for sure...blow a resistor, no fire on that cylinder. So it is one more thing to go wrong. Still, I think you'd be good to go with the 5ks they work fine for me.

Wed Nov 02, 2005 10:13 am

why waste money on sparkplug caps to reduce radio interference.
that is the first thing i throw in the trash when i get a bike that has them.

beerbaron · Wed Nov 02, 2005 12:48 pm

Well, to be honest I've been searching for 2 moths about an intermittent problem. My bike seems to run on 3 cylinders at hight speed/rev. I've fixed a few things here and there but still searching. This problems happens only when I'm above 50 km/h and the engine above 5k, and it only happens about 5% of the times. So you gotta understand that I'm investigating anything that looks suspicious.

Next thing I'm gonna doi is change the spark plug wire (yesterday it was raining and it made it happen more often) so I'm guessing it's directly related to the fire.