Cool cylinder

[TREVOR9]

I live in Wales but have a zr550 B1 in Crete as my transport when I go there. My local bike mechanic was doing some work for me, sticking brakes, and a oil and filter change. He then showed me a temperature gun that showed cylinder 2 was about half the temperature of the other 3, without any explanation as to what the problem might be. I couldn't interrogate him very far as my Greek is almost non existence and his English is worse. LOL Now I'm back in the UK what parts do I take back to effect a good repair. Thought about oversize pistons and rings, until I saw the price. (£111.00ea) without the rebore.eek

[Richard]

Not so cool... (expected to see a picture of a cool cilinder )

Did you perform any diagnostics? Could be a lot of things causing this behaviour.

Did you (carefully) feel the downpipe temperature? I've had it that it e.g. was stone cold. Caused by a dead spark plug.
Did you inspect the sparkplug, was it wet or what color did it have?

[TREVOR9]

Hi, Thanks for your reply. I did have new plugs installed but the old plugs looked okay. I cannot remember the exhaust temperatures, but they were about 80°c on the cool cylinder and about 120°c on the others. As I've said this bike is in Crete, so no more information can be asked until I go back in August. The shims were done last year along with carburetors strip
down and cleaned. The bike on collection was running fine.

[Richard]

So I guess we'll have to wait untill you're there...

Anyway, I would check the downpipe temperature, if it becomes hot after starting at least you have some spark and some fuel. If it's cold check for a wet plug, if so then it's an iginition (or dead plug issue. If it's warm then again check the color of the plug, greyish means lean (check fuel level in carb bowl).

Appart from normal tools I would at least take one or two new plugs with me and a decent volt/ohm meter...