Ack! chewing/scoring on gear? in oil fill hole

See attached pic. I noticed what appears to be fresh scoring on the corners of little square pieces of metal when I look in the oil fill hole.

Forgive me, I have no idea what I'm looking at, but it looked fresh and does not look like it should be like that.

I circled where the corners look like they are chewed on.

For full disclosure, I am new to maintaining my own bike. I bought it a month ago, and it runs really well. I changed all the fluids/filters when I bought it, and boiled the carbs (they were fairly clean except for a bit of rust). De-rusted the tank. New fuel filters etc.

But, I did screw one thing up. I bought the oil at the local gas station 10W30. I didn't realize that car oil is not meant for bikes where it lubes the transmission too. As soon as I read that in the forums here, I went out and bought proper oil and did the oil change with a new filter. (today).

Also, I notice that there is a very faint knocking when the idles are low (ie when engine is cold at it is puttering around 1000 rpm). As soon as I rev, the knock goes away.

Any ideas guys? Am I looking at a rebuild? Any way to tell if that scoring is recent?

 

I'm guess that is the clutch hub? From looking at the service manual. Does that mean I've been sloppy shifting?

 

Hi I can't answer the clutch part of your question. The 'knocking' you hear might be the valves. Have the clearances been checked? (Being able to hear the valves is not necessarily indicative of a problem, but not knowing if they are in spec is risky)

 

I haven't done the valves. No idea if/when PO did them.
Can I ask a dumb question? Are the valves in the carbs or in the engine?
I keep hearing reference to needing to shim the valves to check clearance as a good thing to do periodically or after buying an unknown bike.
Thanks,
David

 

The valves are the intake/exhaust valves in the engine. They regulate the flow dynamics of the carburation/fuel burn/exhaust. Over time they become tighter and can ultimately lead to valve failure/engine failure.
Find bigfitz52's valve tutorial for a better understanding. (Is your bike a 5-valve per cylinder model?)

 

You should get a Yamaha Workshop Manual for your Bike and review the various sections to become more familiar with what gets discussed in these forums.

It will be a valuable resource as a Reference Book and most helpful to anyone who you have assist you in maintenance or repairs.

http://www.animatedengines.com/otto.html

 

The ckutch basket is not suppose to look like that. You have some serious problems going on. Take the clutch cover off and look into it before more serious dammage happens. Something in there needs inediate attention. Take more pics with the cover off and post them.

Don't run the enging until you get to the problem at hand.

 

Thanks. I'll get out the good camera and the allen keys first thing in the morning.

The knocking is actually only there if the engine dips below 1000 rpm. Which I would assume is her just complaining

 

Remember to drain the oil before opening the clutch cover

OT: If the scorings on the clutch hub are recent, they may have been caused by debris caught between the cover and drum. What kind of oil cover cap are you using? If it's anything longer than say 3-4cm into the case, it will rub onto the hub.

 

The photo isn't sharp enough to positively say that anything is damaged.
At best, one could go out a limb and say that the Clutch Basket "Appears" to have some Galling.
Inconclusive.

If you Pull that Cover, ... you'll need a Gasket.

Before you dive-in there, ... I'd make sure that the Clutch was properly Adjusted.

For the 25-minutes or so you'll have to spend getting the Clutch Cable and Connections arranged to give you all the throw-out you can get, ... I'd check to see if the situation improves with a well adjusted Clutch.

With the CABLE Tight, ... you need to have this much distance between the Bracket and where the Cable Pull Attachment PIVOT is located.

 

I agree that you need to have a look. Those are the tips of the ears on the clutch basket and it appears that something has been chewing on them.

Here's what the clutch looks like inside: http://xjbikes.com/Forums/viewtopic/t=29541.html

Your clutch is simpler than the one used to make the pictorial, on the shaft-driven bikes your plain plates have no tabs and there is no oddball "clutch boss spring" (with special friction plate) to worry about.

Otherwise, your clutch operates and comes apart/goes together the same way.

 

Or put the bike on it's side stand

 

Thanks guys. So I don't have a gasket laying around, so pulling the cover will have to wait (if basket teeth damage isn't fresh and ugly). If it isn't a 911 I'd rather be riding while I wait for parts to arrive.

I'll grab a friends good camera and get some detailed shots of everything.

Re: oil cap, it is stock, threads are about 1 cm. And there is no marking on the edges of it.

Re: shifting, the clutch is really smooth shifting, no slipping or grabbing

Thanks bifitz, I read that and learned a bunch more about the intimate bits of my clutch.

Hey Rick, that is of course assuming that wd40 spray tubes are a standard length in Canada too . Seriously though, I'll get that measured and adjusted if needed. I'll need to search the forumns and read up on how best to do that.

cheer, David