Compression Tester

[Hoko]

I was looking at my spark plugs for the first time yesterday. Never seen spark plug holes that deep in an engine! How do you get a compression tester way down there?

[41 Redhawk]

The ones I use had fittings that screwed into the spark plug hole and were attached to a 12" rubber hose.

Here are some examples.

[Kreylyn]

The ones I use had fittings that screwed into the spark plug hole and were attached to a 12" rubber hose.

Here are some examples.

That's basically what my tester looks like.


Long hose (only it was braided, not rubber if I remember right...)

Krey

[Hoko]

The ones I use had fittings that screwed into the spark plug hole and were attached to a 12" rubber hose.

Here are some examples.

Thx for that info man. So you can get it tight enough to get a good reading?

[41 Redhawk]

Yeah, the ones I have used have o-rings that seals it off.

[Phantom552]

Most of the comp gauges have a 12-14" hose extension for that exact reason

Also, protip, should you ever need to do a roadside game of musical spark plugs (don't ask), you can use the airbox drain hose to help get the plugs out of there after you've unscrewed them, and also to get them back in without crossthreading them. Lol.

[Eastern Bloc]

What would be the normal compression readings for a Kat 600 98-02?
And what's the spark plug's thread size?
Thanks!

[92xjunker]

What is the milage? Unless you have mega miles or valve issues, which are obvious. I can't even see a reason for doing a compression test. They should all be pretty much the same. That is what you should be looking for. The book will have the readings by psi I have heard some were at 185# while others are seeing 125#. It's all age and use or abuse.

[Eastern Bloc]

What is the milage? Unless you have mega miles or valve issues, which are obvious. I can't even see a reason for doing a compression test... It's all age and use or abuse.

Thanks,

well I was just interested in testing it since I found a guage with long flex tube and adapters for under 20€ and was wondering whether I really needed it.. but no issues with the bike, currently 200 miles short of 40K miles.

[92xjunker]

Ahhh, gotcha. Always good to know your ride, in depth. Carry on, mate.

[maniac1886]

Ahhh, gotcha. Always good to know your ride, in depth. Carry on, mate.

+1 If you trust it with your life, you should know as much as you can about it.
Not to mention it helps with maintenance down the road.

My old roomate (granted he worked at a metal fab shop) would take an old plug to work, cut it down, hollow it out and fix it to a compression tester fitting for a perfect fit of each bike (mainly just mine and his) but it was pretty cool idea. Just thought i would put that on the table.

[92xjunker]

And there it is, right there.

[Eastern Bloc]

+1 If you trust it with your life, you should know as much as you can about it.

Of course that being a priority but also something like a compression test will let you know whether or not to continue investing in mods, upgrades and aesthetics .. I like my kat but can't see myself overhauling the engine with new pistons, piston rings or cylinder blocks if with set valves the compression was low.

[92xjunker]

I would, the top end isn't too bad on pricing, just did an 88' top end. The bottom end is another story.