1976 KZ 900 #4 plug fouling

bountyhunter wrote:

On my twin when the valve seal failed, I didn't see any smoke at all. But a little oil would run down after I turned it off and foul the plug. Only takes a tiny amount to foul the plug and gravity was running it right onto the plug tip.

Could you fix that by moving the side-stand to the other side of the bike? :laugh: :laugh:

loudhvx wrote:

bountyhunter wrote:

On my twin when the valve seal failed, I didn't see any smoke at all. But a little oil would run down after I turned it off and foul the plug. Only takes a tiny amount to foul the plug and gravity was running it right onto the plug tip.

Could you fix that by moving the side-stand to the other side of the bike? :laugh: :laugh:

You're laughing, but I was sticking a 1" thick board under the stand when I parked it...... but the valve seat was so gunked up with cooked on oil the valve was not sealing well and compression was dropping.

I had 60,000 mikes on my 76 KZ900 and it burned oil like crazy. It never fowled out plugs again after I discovered the non seating plunger.

I'm gonna call my buddy tonight and give him a list of things you guys mentioned here. I'm going to ask him about this carb interchanging too....

He just texted me and said he is pulling the head to get a look at the valves. Is there anyway to tell if your valve seals are leaking? Also, how do you change them?

Thanks!

With a bike of that age, it is a given that they are hard and leaking. If he has the skill to pull the head off he must have the skill to do a valve job.

Can you remove the seal without taking the valves out?

No you can't. Even when you remove the valve springs it will be hard to "see" much of anything. If he is going threw the expense and time of pulling the head just do the complete valve job. It only makes sense.

Hi guys, thought I'd wrap this thread up finally. My buddy said he checked everything up and down, from the carbs, compression, timing, valve shims, valve seals and electrical. He finally bit the bullet and pulled the head. Said the head gasket was leaking on a stud or something, but was allowing oil into the cylinder, causing #4 to foul. Seems odd that the compression would be ok, but still be able to leak oil in. Anyway, he was putting everything back together last night.

Thanks for everyone's help.

A leakdown test would have told you that too.

I don't think he had tried that or has one... Might be something to add to the xmas list.

apbling wrote:

...76 KZ 900...fouling issue on the #4 plug...He said it doesn't smoke at all...has 125 psi on all 4 cylinders....

...head gasket was leaking on a stud or something, but was allowing oil into the cylinder, causing #4 to foul. Seems odd that the compression would be ok, but still be able to leak oil in....

Also odd that it reportedly didn't smoke at all. :huh:

Good Fortune!

this is true....

in the beginning of my wrenching career I learned AlOT from him. Fast forward 10 yrs, and I think the student hasn't become the master yet, but at least knows whats going on now.

I guess this is the kind of information you can expect through texting/email...