head gasket leak and knocking sound

[alleyrat]

So i was riding home and the engine was purring... a guy at my weekly motorcycle meet up told my i needed to tighten my chain tensioner to fix my idleing problem...on my way home it was purring and all the sudden it started making a knocking sound from the right upper side of th motor and lost power, i limped it home and adjusted the chain tensioner...two days later i get it out again and take it for a spin and it is still making the knocking sound....I pull over (because of a slipped clutch cable and see oil coming from the front of the motor around the head gasket....any ideas on what it could be....Im tearing it down tomorrow to see whats going on...any input would be helpful
J

 

[tkent02]

Not sure what you may have done to the tensioner, it is completely automatic and adjusts itself constantly while you ride.

 

[alleyrat]

I found out what the issue was...The counter balancer wallered out and went into case...has anyone ever replaced the bearings in a 450...are they all the same...or are they specific to the crank and balancer...I saw different ones on cheap cycle parts that had different colors in the parts description, didn't know what that meant... any help would be appreciated
J

 

[SqDancerLynn1]

Could be just a loose clutch hub

 

[Guest]

On the balancer you can replace the bearings and the race on the right hand side.

On the left just replace the bearings. The case can take a beating and just need a new bearing from one that i've seen. It was bad! but the case hole was round.


If you look at the back of the top case half there will be 6 letters.


Like
A....A Balance shaft
BBBB Crank

Then on the balance shaft there will be an A or B or C stamped or etched onto it.

You have to take the A from the case with the B from the balance shaft to give you a brown or black shim.

The color means a certain size, Brown, black, red....

In the manual there is a chart that says: B,B is brown, B,A is black, AA is red or something like that, I cant remember but you get the idea?

Only way to know for sure is to plastigage it and see what you need with the proper one that is supposed to be in there.

I'm guessing its a brown or black as that's the only ones Ive seen in 3 motors for the shaft. Maybe someone local can send you a spare set to try and then see what you need.

Oh and they are $10 a half , so you need $40 worth of bearings if you go new.

Been there recently

12 bearing halfs later what a pain!


So how did this happen ?

My first thought would be oil starvation. On the one occurrence I've seen this, The owner used gasket maker on the clutch case cover and it ended up plugging up the oil passage to that bearing. Just something to keep in mind.


As for the top end it could be the head gasket because the outer 4 studs are the oil galley's for the top end. There are no o-rings on these but the gasket its self has a ring around these 4 studs.

Oh and we NEEED to see some pics