Download presentation
Presentation is loading. Please wait.
1
Ignition Systems Chapter 9: Part 2
2
Ignition Coil: Composition
3
Ignition Coil: Composition
5
Spark Plugs Come in a variety of configurations
Each type is manufactured for a desired outcome Very specific tolerances Contain many of the same parts across plug types
6
Spark Plugs: Parts
7
Plug Leads Exposed Clip Connector Advantages
Less expensive to manufacture Easy to add a “Kill Switch” Disadvantages Exposed to dirt, oil, moisture, animals Easy to ground accidently Can lead to arching or flashover
8
Plug Leads Advantages Boot Type Connector Virtually eliminates arching
Reduces flashover Protects terminal nut from debris Disadvantages Higher manufacturing cost Requires another type of “Kill Switch” Not as easy to remove
9
Spark Plug Reach Correct length must be selected
To long = piston damage To short = poor combustion
10
Spark Plugs: Parts
12
Spark Plug Reach Long Reach Cylinder Short Reach Cylinder
13
Find your Kohler spark plug. Find your paper in file cabinet
Find your Kohler spark plug. Find your paper in file cabinet. Grab a Champion Spark Plug Chart. (On the podium) Use chart to “decode” your plug.
14
Reading Plugs
15
Reading Plugs: Champion
16
Plugs and Manufacturers
wapedia.mobi
17
Plug Heat Transfer Plugs must deal with heat
All plugs have a heat range: from HOT to COLD Insulator nose size helps regulate plug temp Plug needs to match specific engine
18
Spark Plug Heat Transfer
HOT COLD Insulator nose is longer Less likely to ‘foul’ from carbon deposits Using a plug that is to hot can result in engine failure Shorter insulator nose Transfer heat quickly Used in engines with HIGH COMBUSTION temps Note: the hottest part of the plug is the tip of the insulator!
19
Spark Plug Heat Transfer
HOT COLD
20
How do they measure plug temps?
Thermocouple Plug
21
Gapping Plugs Gap refers to space between electrode tip
Specific to engine type in conjunction with correct plug selection Must be installed to manufacturers specifications
22
Gapping Plugs: measure then bend
1. Verify dimension with specs 2. Check gap 3. Use notched end to bend to desired clearance
23
Most common gap .030”
24
Electrode Designs Most common
25
Electrode Designs
26
Electrode Designs
27
Problems with Spark Plugs
Flashover Bridging Fouling Detonation Worn electrode Melted
28
Flashover
29
Bridging Accumulation of deposits on the electrode Can be caused by:
Oil inside the combustion chamber Plug is the wrong temp range Can also be caused by fuel additives
30
Carbon Fouling Carbon deposits can build up on the electrode
This eventually causes a conductive path from electrode to the ‘reach’ (threading) Plug continues to ‘fire’ but spark does not occur Causes: rich fuel mixture and or cold plug
31
Detonation VERY BAD!! Can cause severe engine damage!
Looks like bits of pepper on the electrode Fuel is not completely detonating Causes: Improper octane fuel Incorrect timing Wrong plug temp
32
Worn Electrode Note the rounded electrode Plug needs to be replaced
Simply worn out Replace with correct plug to manufacture specifications
33
Melted Electrode Oops Potential causes: Wrong Plug
Timing to early Faulty distributor Wrong Plug Not commonly found on single cylinder engines Check engine manufacture specifications and replace immediately
34
Review: Parts
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.