08-01-2010, 09:22 PM #1
Ignition Coils Cracked, and basic maintenance
Having seen this many times, I figured I would do a quick write-up for all to read.
Getting the coils back to something reasonable is easy to do.
Take connectors off each one, remembering not to loose the little red silicone seal as you un-plug them.
With a 1/4 turn twist clock-wise, pull the coils upward to remove them.
Try to order them to relate to each cylinder for reference later.
Look inside the hole they were in, and get a compressed air blower, and clear them out of anything you can, which may be moisture, rust or odd "stuff".
The plugs will need to come out later, as inevitably, there will be contaminants that have adhered to their insulators, but do this later, and avoid any debris getting into the cylinders.
Each coil consists of a formed plastic inner, which encapsulates the coil, and its connections.
The coil is "Shielded" for electromagnetic interference purposes by a soft iron shield, and it is this which corrodes all too easily, ....and when it does, it swells up, and causes the outer plastic cover to crack.
This swelling will often make the coil difficult to remove as it swells to fill the hole it normally is situated in, and can adversely affect it electrically.
Now the thing to do is to remove this plastic cover and then the soft iron shield, revealing the "Business end" of the coil itself.
To do this, manipulate the coil nose seal off the tip of the coil, remembering the moulded seals are formed to hold the seal on, by a series of reverse barbed mouldings on the coil body.
These seals is invariably contaminated, and need to be cleaned to eliminate any way for the spark to leak away outside the place it should do.
The thing is to remember here is that many performance coils produce a higher voltage to ignite the mixture in the cylinder.
The gap the spark jumps across in the cylinder is getting increasingly difficult to jump across as the cylinder pressure and mixture increase in density, as we force more fuel and air into the cylinder. In fact, it begins to be an insulator as this happens. So every volt of the 25Kv(25000) or more counts at higher RPM and power.
Remember, the better the spark, the more power we can extract from the engine. (often highlighted by the likes of MSD and other performance coils on the market)
So..... the tip has to be clean, and untouched by hand when replacing it. This also extends to the insulator of the spark plug.
We benefit by keeping these clean, and un-contaminated... actually more than we would imagine!
Anyway, at this time, the next thing to do is remove the outer plastic cover that covers this Iron shield. Generally, in this case, you will see a split in the surface, so gently pull this crack apart, and remove it revealing the rusty shield. Gently open this apart, and slide it off.
The plastic cover, and iron shield are now surplus to requirements, so bin them.
Now you will be looking at an almost "spindley" coil core when compared to what it started out as. This you can clean over, and slide the top seal off at the same time.
You will notice the seal has a series of detents where the tags of the coil top moulding engage into to keep it in-line, and make sealing this area from moisture easier.
I use carby-clean to clean the coil and silicone seals with a soft, clean, lint-free cloth.
Remember to clean the tip of the coil moulding, as this is normally covered in a rusty conductive substance, which may provide a path for the valuable H.T. (High Tension) volts to escape being forced to discharge through the spark plug in the cylinder. This is often overlooked at service times.
When finished cleaning the seals, the coil can be re-assembled, noting that the top seal is orientated on the tags at the top of the coil, and the tip seal is also pushed back onto the coil over the barbs.
When re-inserting the coil, I lightly smear the outer edge of the spark plug hole with petroleum based grease, which helps to get the seal in the edge nicely, and provide a better moisture proof seal. Push the coil in, but be about a 1/4 turn anti-clockwise. You will feel it going on the spark plug top, as it seats, turn the coil the 1/4 turn to put the plug in line with the connector.
Remember to watch that the little red silicone seal is not mis-placed, and seats in the connector smoothly, and uniformly.
Loose this seal, and moisture will get into the contacts, and electrically will cause you problems quite quickly. If you do loose it, get another, and don't put the ski in water until you have replaced it.
Now as far as the life of the coil, I have never noted any side effects by carrying out this proceedure. The tip of the coil is at the hottest part of the spark plug hole, and the plastic here never appears charred, or damaged in any of the conversions done.
The coil runs quite happily in the environment it lives in, but as we know, there are faults that can appear over time, and use.
We do need to know that all the coils are developing the highest voltage they can at the tip only, and that we do not provide any path for the H.T. to leak away un-used. Removal of this Iron shield helps eliminate this by removing any further chance as a way of a bridge to ground, or the engine structure other than through the tip, and on to the spark plug into the cylinder.
Always keep the plug insulator clean and un-touched, along with the area at the nose of the coil, keep this clean, also along with the seal, It will always pay off for you. Even if there is one misfire by one single spark failing to go where it should, the power will be affected, so eliminate this at all times by clealiness.
As a mis-fire from failed spark can cause fuel and air to be "Un-spent", and sitting in the engine, it can give odd results and readings... plus, the power per stroke is reduced.
Next, get the plugs out, but remember to blow any debris or moisture out before-hand. Do the plugs one at a time, to reduce the chance of getting anything in the cylinders at any time. Usually, a good practice is to crack the plugs loose, and blow the plug hole out again, as dirt can fall off where it was lodged before you took a wrench to them.
Clean the insulator of the plug before re-inserting them with carby-clean, and not touching the insulator at any time. Try to hold them by the metal parts only, as these are meant to conduct.
The reason I say do not touch the insulator is the small amount of our "finger-print" will begin to change its properties, and under heat etc will begin to help form a bridge that the HT can use to jump across to ground, and not through the spark plug gap in the cylinder.
Every little counts on performance engines, and one of the main things is the mixture igniting spark.
The main problems in ignition at this stage are generally the state of the connectors, and moisture or contaminants in the spark plug hole.
One of the most common problems is caused by this little red seal going walk-about, and mosture getting into the connector.
Over a short period, the connection will corrode, and insufficient current will flow through the coil, and effectively weaken the voltage the coil can produce.
A good spark equals good ignition.
Last edited by Richieb; 08-01-2010 at 09:31 PM. Reason: edit
08-02-2010, 05:54 AM #2
08-02-2010, 08:29 AM #3
08-03-2010, 05:15 AM #4
- Join Date
- Aug 2006
08-03-2010, 05:19 AM #5
- Join Date
- Aug 2006
opps there is supposed to be only 9 pictures, sorry about the coment on the shell with Reid's brain disregard that hope the pictures help?
08-04-2010, 07:08 PM #6
- Join Date
- Jul 2005
- euxton nr chorley lancashire, england
my coil packs were stuck very tight because of the swelling corrosion of the steel sleaves under the insulater plastic covers, why did bombardier use mild steel metal instead of a stainless sleave for these coil packs?
08-06-2010, 08:42 PM #7
so if my interpitation is correct remove the outer plastic cover..and then the rusty shield..and it is ok to run...
i assume you put the plasic part of the shield back on less the rusty part...i used 1 inch heat shrink tubing ...a while back just to seal everything..because i know they do this...but didnt diassemble.and remove the rusty part...they are starting to get tight..
i have allways used dielectric grease on the end of the plugs..and the connection to the coil ??? good or bad???
08-07-2010, 01:31 AM #8
- Join Date
- Aug 2006
Last edited by Jammer 1; 08-07-2010 at 01:37 AM. Reason: still trying to figure out WTF am I drinking.....
08-07-2010, 05:36 AM #9
i have been using the dielectric grease on every electrical connection..on the ski...accuallly carry it in the ski..i also ride alot of salt in fla ..
i use clear motorcycle chain wax on things like the driveshaft ..doesnt sling.and make a mess...or wipe off or get on everything it touches..like grease..and gives great protection...so far after 3 years i am doing good..
just wasnt sure if you were removing the shielding......thanks for the clarification...
as i stated 1 inch heat shrink fits nicely over the tube on the coil then i sealed the ends with brush on electrical tape.... to help keep the crap out..and hold it all together..
the only think i have found if things are all lubed up...somtimes the coil packs will be pushed..back off after the first ride ..think it is the air heating up...usually if i push them back while the engine is still hot..they stay ..
you can take your slo dude big daddy thing where you want with that...LOL
08-07-2010, 09:47 AM #10
- Join Date
- Aug 2006
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By fastkaz in forum Yamaha PWC Performance (2-stroke)Replies: 1Last Post: 01-07-2008, 06:12 PM
By fastkaz in forum Yamaha PWC Performance (2-stroke)Replies: 11Last Post: 07-05-2007, 10:27 PM
By Bamafanatic in forum 4-Tec PerformanceReplies: 3Last Post: 05-23-2007, 10:03 AM
By addicted in forum Yamaha Old School SkisReplies: 1Last Post: 05-23-2007, 12:09 AM
By Rodneyae in forum Polaris How To & FAQsReplies: 5Last Post: 02-13-2007, 11:54 AM