Tick

Is/was there (enough) oil in it? How long have you had the bike and known it's history? Crank bearings don't usually 'just go'.

 

Oil was changed regularly . Had the bike 2 years .My father had it before me.
I just cant tell where the noice is coming from. Only hear it when riding. But kinda sou d like a vtwin at idel and take off .

 

check the header pipes see if they are tight or leaking exhaust

 

Try a new set of plugs

 

Remember, plugs need blue or purple spark to fire. Orange or yellow spark is a fouled plug.
Fouled plug can cause a misfire, therefore knock

 

Merged so we can all re-read the whole history of the machine.

 

Not always the case with a TCI ignition.
Color tells you the temerature of the plasma that's is formed, and that is dependamt on the discharge voltage, and that is lower in a TCI system. XJ spark is typically more orange than blue.

 

My last post has nothing to do with this thred .

 

Then what bike ARE you talking about

 

Talking about my 86 .But why merge threds when this is a hole new topic.
My bike was great all year .Now has power loss sounds like a vtwin .And has a rattle .

 

Not the plugs .

 

Ok, so below is your previous post.....

Ok..... So you have 2 '86's? Cuz it sure sounds like you had 2 different threads going about the same bike. THAT would be why the threads were merged------so we could keep track of ONE bike.

 

Sound like alot of work to me. Anyway dont seem like theres any help here.
Well done .

 

So, since everything is right here in this single merged thread, I was able to read through the whole thing.


Check valve clearances.....you said you did it

Suggestions made:

Recheck valve clearances.....you said you did it
Check your exhaust pipes for leaks......did you do it?
Try a new set of plugs.......did you do it?

Have you done a compression test?
What clearance chart did you use for your clearances:
Do you have a video that you could post so we could actually HEAR what you're talking about?

 

Rattle happens on take off and when you let off. Sounds like metal hitting metal .
Did it more when it was cold less when warm. Collars are tight on pipes and tried new plugs .

Compression test is next .
Ill try a vid next as well .

 

Broken valve maybe?

 

That's why we need a compression test.... and also to hear

 

Ill get to that next. Bike is an hour away now at my fathers..
Just out of curiosity . Would a burnt valve make a rattle.
It does seem to have the burnt/broke symptoms. But dont get the rattle part.

 

I agree, had the same rapping sound that went away when I installed the missing exhaust gaskets.

 

Burnt valves don't rattle.

What can rattle (in addition to loose exhaust headers, and the other suggestions) are the chrome shields on the exhaust collector. They are spot-welded on, and the welds can crack.