Spark plug boots

On my new to me '91 K100RS I tried to change the spark plugs but the boots seem to be stuck on the plugs any hints or tricks how to fix this?

The boot has a metal tab. Grab it with a pair of pliers, wiggle and pull. You will need to pull them fairly hard but they pop right off.

Boots

I did try pulling them fairly hard and got no discernible movement at all, I don't know how long they have been in there so I wanted to change them. (I have had 2 KRS's in the past so it is not all new but am starting a new learning curve, the bike was not as well taken care as I usually do to mine which is why I got a good price for it, but the little things begin....)

My 1985 had the original plugs until I bought it two years ago.

Pull VERY hard this time. Make sure you are up on the center stand.

The factory tool is actually a pair of special pliers with a pin in the center of the jaw that goes into the hole in the tab on the caps. I found "gas pliers" work well, as does a metal hook with a handle on it. Don't pull the bike over on yourself.. and you might put a tiny smear of silicone grease on the rubber before putting it back in - that will keep it from sticking again.

You can rotate the boot left and right just past the point of resistance NOT to the point of bending the tab.

Each time should yield a little farther turning until the boot will become unstuck, then PULL.

Worked for me. Your results may vary.

Slightly grease boot upon reinstallation as Don said. This IS a good spot for dielectric grease.

A warm engine has more pliable boots.

On one of mine, they were so stubborn once, I had someone else spot the bike as I gave a really hard yank. Got them off, but I darned near fell over and the bike would have gone the other way if not for the spotter. Never had quite that issue with that or any other bike again.

boots

I had thought of heating them with a heat gun on low that way they would be more pliable and the plugs would not be heated up.

bakrd said:

I had thought of heating them with a heat gun on low that way they would be more pliable and the plugs would not be heated up.

Click to expand...

Once you get them off you might consider pulling the plugs (clean around the openings with compressed air first) to see if the lazy former owner ever replaced them and/or used the correct heat range and style.

I recently replaced the plug wires and plugs with ones I bought from Motorrad Elektrik (they advertise in the Owners News). The price of the new set of NGK wires and plugs was less than the cost of one plug wire from the dealer.

The bike had been running on something less than 4 cylinders and the improvement was noticeable on the first ride. The front most plug had always been a bit wet compared to the back three plugs. The wires tested out right around 5K ohms where they should be, but my suspicion is that vibration or heat from running caused the front most plug wire to not work properly. Gas mileage improved, too, and by about 3 mpg.

Interestingly enough the plugs I pulled out were some totally random set of Bosch plugs that bore no resemblance to the correct Bosch numbers. They fit and the bike ran so the previous people left them in. Sigh.

After that change, with the help of one of the local dealer's mechanics, I found the vacuum pull off covers (little rubber covers) were cracked and leaking. Replacing them restored power at highway speeds where, if I am correct, the bike was running too lean before. You need three for a K100. The dealer price was $1.20 each which, while highway robbery, is the cheapest performance improvement I've ever gotten.

Good luck and consider tossing those 20 year old plug wires (or at least retiring them to backup duty).

-Gary