Honda BF135a Coil Spark Plug Boot Separation Problem

I like to fog the cylinders every storage season and last year when I changed the plugs on this 2007 Honda BF135A (type BARJ300712), some of the spark plug boots started separating from the coils in the Spark Plug hole and staying on the plug making plug removal impossible until boot is extracted with difficulty. And then, when you do get the boot and plug out, the boot and coil won't go back in together because the boots seem to have swelled and expanded over the years creating an airtight seal stopping re-entry. You are forced to push the boot in separate and then insert the coil. I am wondering if the only cure or this problem is 4 brand new complete coil and boot assemblies at $70 a pop....or is their a simpler less expensive solution?

Hi Denny

If it was me then it`s time to bite the bullet and spend the money on new ones as reliability is key to anything we do out on the water.

Do it right once, rather than trying to do quick fixes that you know in the the back of your head just ain`t right.

Cheers, Matt.

????----Why not find a way to inject fogging oil into the intake air stream..----A lot less work I would say.

Thanks Matt and recerone....great advice!

The auto repair industry experiences this... and many more issues... with the COP (coil over plug) ignition systems. It has become a fairly standard practice to replace ignition coils MUCH more frequently than was ever done in the past.

It used to be that the old "low output" coils of your "father's outboard".... and auto......, would last for many, many years. But, with today's higher firing voltage coils, "winding breakdown" happens with greater frequency. And with the coils being fired by "drivers" in the very expensive ECM instead of a relatively cheap "module" or.....going WAY back...points.....an internally shorted coil can take out your engine computer very easily. Or...even worse....PARTIALLY take out a coil driver or two....setting up an "intermittent" misfire scenario that COULD lead to time consuming....thus expensive....diagnostic time in the shop that STILL leads to computer AND coil replacement!

So....even though I highly doubt that ANY of the manufacturers would just come right out and say it....the thousands of independent repair shops....and many dealers.....are getting in the habit of changing out "suspect" COP coils as a precaution.

I once heard a very renowned race car mechanic say..."anyone that tells you he knows EXACTLY how a magneto works is lying to you". Well, coils are a BIG part of the magnetos he was talking about and even with today's DSO's (dual trace oscilloscope) and high speed, graphing multimeters......coil diagnosis remains something of an "art".

I see reports on almost a daily basis, written by mechanics on my "for professionals only" auto repair forum, about coils causing issues. These guys use the latest, most expensive test equipment to be found and, sometimes, they just end up swapping the coils around to pinpoint a bad one.

I tell you all of this so that you will see that it's not just happening to you and to try and take some of the "sting" out of what you may find is the easiest and LEAST expensive way to proceed.

The old saying..."discretion is the better part of valor"....probably doesn't apply here.

But..it's a B.O.A.T. so.... Break Out Another Thousand....probably does!

Good luck.

Hi Denny
other than possibly renewing the coils, or just the boots if can find some e.g. good 2nd/h automotive ones would be cheaper, I would check the cause of the boots swelling.
They don't normally swell unless they have been contaminated by oil for a while.
There's a chance your spark plug tube seals are leaking oil & need renewing #3 http://www.boats.net/parts/search/H...er/BF135AK2 XA/CYLINDER HEAD COVER/parts.html

If they are the cause & you're going to renew those, then you might also want to renew the cyl head cover gasket #2 & check your valve clearances while the cover is off.

Bob