Loose Plug Wires Question?

bcar00 · Tuesday at 9:58 AM

Doing maintenance and decided to check/change the plugs while I had the tank off. All six plug wires were loose on the plugs. I know that isn't uncommon, but for those who've had this happen, do they come loose again, or once they're on tight do they stay?

I'm wondering if this is just an issue with the factory installation, or are the boots defective? Too short? I've read in other threads that they're a hassle to get on correctly. Just wondering if I need to replace them? Anyone check theirs at the next service after putting them on tight?

thanks

imcool · Tuesday at 10:34 AM

yes, known issue,
the spark plug boots lock springs are not good,
I had to use a pointy thin tool and pull the spring outwards, its tricky but can be done and your spark plug boot cover will be really tight and snug

bcar00 · Tuesday at 11:56 AM

imcool said:
yes, known issue,
the spark plug boots lock springs are not good,
I had to use a pointy thin tool and pull the spring outwards, its tricky but can be done and your spark plug boot cover will be really tight and snug

Outwards? So you loosen the springs?

imcool · Tuesday at 12:07 PM

bcar00 said:
Outwards? So you loosen the springs?

this is how it looks on rocket spark plug boots for 2.5

Journeyman · 2026-09-16T06:00:11-0500

I'll try that next time. I just forced them on with an open end wrench (or other pushing device). You have to push harder than whatever young girl was given that task at the factory (pretty hard) to hear it click into place. Mine stayed put each time after that. Amazing that it ran OK sitting loose

bcar00 · 2026-09-16T10:53:49-0500

Reinstalled last night. I had to do the opposite. Mine were too tight. Even with the plugs out of the engine, it was super difficult to push them on.

I also think the main issue isn't that mine were loose on the plug, it's that the plug boots are about 5mm too short. When I tried to install mine, I wasn't just pushing against the plug, I was pushing the cap against the head. Others may have a different situation, but mine were not going to go on, even with a sliced wrench and all of my 200lbs.

I ended up cutting down the cap so it (tightly) sinks into the hole, instead of on top of it. Even then, it took all my strength to push them on. I can see how, even if they were partially on at the factory, the constant upward pressure from the cap would eventually cause them to vibrate off. Maybe not an ideal solution if you ride in a lot of heavy rain, but I think it still seals, and allows the boot to permanently sit where it needs to sit to stay on the plug.

Journeyman · 2026-09-16T11:24:01-0500

bcar00 said:
Reinstalled last night. I had to do the opposite. Mine were too tight. Even with the plugs out of the engine, it was super difficult to push them on.

I also think the main issue isn't that mine were loose on the plug, it's that the plug boots are about 5mm too short. When I tried to install mine, I wasn't just pushing against the plug, I was pushing the cap against the head. Others may have a different situation, but mine were not going to go on, even with a sliced wrench and all of my 200lbs.

I ended up cutting down the cap so it (tightly) sinks into the hole, instead of on top of it. Even then, it took all my strength to push them on. I can see how, even if they were partially on at the factory, the constant upward pressure from the cap would eventually cause them to vibrate off. Maybe not an ideal solution if you ride in a lot of heavy rain, but I think it still seals, and allows the boot to permanently sit where it needs to sit to stay on the plug.

Yes, too tight, as in hard to push on. We're saying loose because they were just resting loose on top of the plugs. You're right about the caps. If you push hard enough to seat them the larger caps that cover the spark plug hole kind of sink down in the middle (concave), but don't fully go into the hole. Not sure that is clear to everyone else, but you know what I mean. As they were, the large caps rested on top of the hole and the part that clicks onto the plugs was not clicked in- just resting "loose."

Loose Plug Wires Question?

bcar00

.040 Over

imcool

Turbocharged

bcar00

.040 Over

imcool

Turbocharged

Journeyman

"And this one is just right" ~ Goldilocks

bcar00

.040 Over

Journeyman

"And this one is just right" ~ Goldilocks

Similar threads

Forums

Features

Forum Usage