where to mount coil

Kevin Edens · Posted: Mon Aug 20, 2001 4:04 am Post subject: where to mount coil

Looked at a few karts this weekend and saw many differant techniques. Where is the best place (seat, motor, etc. ) to mount the coil?

Kevin Edens

John Clasen · Joined: 04 Aug 2001 Posts: 563 Location: San Marcos, CA

Kevin, like most electronic components, coils are not fond of heat and vibration. Take that into consideration when deciding. It is an easy process to put a longer lead wire on the CR coil (if that is what you are running). It simply screws in and there is no measurable resistance increase with the added length.
J.R., PSR

Greg Maxwell · Posted: Mon Aug 20, 2001 6:42 am Post subject: where to mount coil

Kevin, If you mount the coil on the back of the seat you can have problems with your cdi box (if they are to close to one another) I chased a high rpm miss for 6 months, untill I remounted the coil back on my engine. So my vote is mount it on the ENGINE. Greg

Jeff Morningstar · Posted: Mon Aug 20, 2001 11:55 am Post subject: where to mount coil

I have had good luck on the side of th motor mounted in rubber.

Erik Frank · Posted: Mon Aug 20, 2001 12:01 pm Post subject: where to mount coil

Mine is on the seat. As J.R. states, heat and vibes are no-no's for coils. I've been running the same coil mounted on my seat for two years, and never had a problem. Be sure and run a ground strap fom the coil to a seat strut (or chassis) to prevent RFI with the CDI box.

-erik

Greg Maxwell · Posted: Wed Aug 22, 2001 9:07 am Post subject: where to mount coil

Erik, I had an 8 gauge ground wire and still had the high rpm sputter. I also changed every electrial part, some twice, still had the sputter...untill I moved the coil back to the engine (rubber mounted). I couldn't believe it myself (that I was having a problem while so many people have it mounted on the seat) Greg

Charlie Tackett · Posted: Wed Aug 22, 2001 9:33 am Post subject: where to mount coil

I simply run a long bolt thru the engine mount section on the back of the cylinder head, place a thick rubber seat bushing and lg washer between the coil and the engine and us a large washer and lock nu on the other side. Same coil has been there for a coupleof years now and no grounding problems. Cost of mount is probably less than $2.e

John Denman · Posted: Wed Aug 22, 2001 10:27 pm Post subject: where to mount coil

quote:
Originally posted by Greg Maxwell #34s:
Erik, I had an 8 gauge ground wire and still had the high rpm sputter. I also changed every electrial part, some twice, still had the sputter...untill I moved the coil back to the engine (rubber mounted). I couldn't believe it myself (that I was having a problem while so many people have it mounted on the seat) Greg

Most of the CDI boxes OEM or PI have no shielding for RFI. Same goes for Mychron stuff. Even when routing cables, the high tension coil wire should not run alongside CDI or Mychron wires (except the Tach wire).

You may notice on some motors a 6AWG wire going to the ground. Simple thinking would say that was certainly enough to carry the small amount of current, but high voltage does some pretty wicked things that don't show up on meters. A heavy gauge flat braided wire works best as a ground for a coil.

Erik Frank · Posted: Wed Aug 22, 2001 10:48 pm Post subject: where to mount coil

Another possibility might be the type of ignition wire you are using for the high tension lead from the coil to the plug. Is yours OEM?

Most certainly, as John states, the proximity of the HT lead to low voltage signal lines can also lead to problems. (been there, done that) I should have mentioned that on my setup, the HT lead is routed away from the main CDI harness.

Ed Weathers · Joined: 19 Jul 2001 Posts: 36 Location: Hood River, Oregon

I've mounted my coil in all of the places mentioned in this thread. My new Honda from Reinne took away the cylinder head method of mounting. I took two honda rubber mounts and mounted it off the intake. Solves vibration heat and interference from the cdi.