Guardian 5338 - Stuck ignition wire boots

[WB5CCO]

While performing preventive maintenance on my Guardian 5638 having a Mitsubishi 2.4 liter 4G64 engine I discovered three out of the four ignition wire boots were stuck to the spark plugs and/or the outer metal sleeves. Using recommended removal tools and techniques proved futile. I successfully removed two of the stuck boots piece by piece using pliers and plenty of leverage. The third boot required freezing with R34 refrigerant, a trick I learned from an aircraft mechanic. I removed and checked all four spark plugs, replaced and torqued each to 18 foot pounds. I installed new ignition wires using ample ignition "boot grease" on the spark plug terminal, terminal wire connector and boot. Examining original wires removed from the engine revealed no evidence ignition "boot grease" was used. I am fortunate I discovered this issue during preventive maintainence and not after a failure during a sustained power outage.

[NYS SitePower Corp.]

WB5CCO - That one is definitely worth mentioning!

The 2.4 is a great engine, but that really a gem of a plug boot design. Even when they are new, its tough to get the boots off. We grease them up before the unit leaves the shop, or at the startup inspection in hopes that removal will be easier down the road.

[grasscutter]

Richard did you replace the plastic tubes that broke & how did you get the pieces out from the metal tube that goes in the head,hopefully before you removed the sparkplugs?

[WB5CCO]

I replaced the ignition wire set which came with the plastic tubes attached. Make sure you lube them liberally with silicone ignition lubricant. The plastic tubes broke in to pieces when I tried to remove them using spark plug removal pliers. I resorted to several different types of long nosed pliers and hemostats to pull the remaining stuck pieces out. They are very brittle and will easily break into smaller pieces. I recommend having a pair of Gearwrench model 3832 ignition pliers (KD Tools) to remove the boots in the future. Expensive but a great investment. The replacement ignition wires cost around $38 from Autozone (Dura-Last 9055).
Good Luck!

[grasscutter]

Thanks a million again Richard.