Cam Cover Plugs Question

I am having a heck of a time with the rubber cam cover plugs on my engine. For the second time in a row, they have slid out when taking my bike on a test ride (just re-assembled the engine).

What a mess when that happens! Oil pours out like crazy!

Don't know what I am doing wrong - too tight or too loose? I tried coating the edges with gasket sealer and without and they came out both times.

Has anyone tried the aluminum plugs available from APE? I am considering ordering a set of those tomorrow...

One of the best investments you will make. Never have to worry about the plugs sucking in or out. You'll never have to replace them again.

If you're attempting to reuse your old plugs, there's your problem. Once removed throw them away and replace them. I have never used the ape plugs so can't comment there, but never have a problem with the stock ones at all.

An old trick I learned years ago is on the older KZ's is to install the cam plugs backwards! Put the lip on the inside of the engine. It might look funny but it seemed to work.

Another one was to use the plumbers white teflon tape on the cam plug,maybe a turn or two after its been cleaned.

Give this a try I don't think this will work on the later years engines as I believe a 6MM bolt goes through the cam plug.

Mfolks i believe you are right about the later years. On my 82 Spectre the bolt does go thru the plug. I put a little clear silicone on mine when i installed the plugs and never had a problem.

Turning the plugs around is definitely an old racers trick that really works. I have used aluminum plugs for years and they have a lip on both sides. Either way, even with new plugs, use some sealer and you should be OK.

i have reused mine a few times now with no leaks. i put Permatex silicone rtv gasket glue on them.

You might look at why the plugs are popping out. Is your case breather clogged? If its building up enough pressure to pop out the cam plugs you might check it.

Scoot Jockey wrote:

I am having a heck of a time with the rubber cam cover plugs on my engine. For the second time in a row, they have slid out when taking my bike on a test ride (just re-assembled the engine).

It says right in my FSM that you must use a sealing agent on the plugs to hold them into the head. Yamaha 3-bond or any very good RTV sealer will work. Clean the head surface and then glue the plugs in and let them cure before torquing the cam cover on.

RonKZ650 wrote:

If you're attempting to reuse your old plugs, there's your problem. Once removed throw them away and replace them. I have never used the ape plugs so can't comment there, but never have a problem with the stock ones at all.

The only problem I have had with the stock plugs for the old 750 twin is they set me back about $60 for a new set..... you can believe I re-used those old ones a long time before I chucked them.

bountyhunter wrote:

RonKZ650 wrote:

If you're attempting to reuse your old plugs, there's your problem. Once removed throw them away and replace them. I have never used the ape plugs so can't comment there, but never have a problem with the stock ones at all.

The only problem I have had with the stock plugs for the old 750 twin is they set me back about $60 for a new set..... you can believe I re-used those old ones a long time before I chucked them.

That's all true, but the question is why ever remove them? I never remove mine unless they are leaking, but if they are I promptly throw them away. I'd rather not disassemble over and over to save $15, been through that before Then again I have like 20 or 30 new plugs ready to be used so they've already been purchased years ago. I know "old rubber", heard it before. I never have a problem.

RonKZ650 wrote:

I never remove mine unless they are leaking, but if they are I promptly throw them away.

I agree with the first part for sure, but I got a whole lot more miles out of them by resealing them with very good RTV sealer.