Weird noise from engine?

Hey guys, so I recently check and adjusted all the valve clearances! I was riding it a bit around my property and I noticed a metal rattling sound on the right side of the motor, I can't tell if it's from the top end or bottom end! I was cruising slowly in first gear and it didn't sound too good! It's been ok until now! I'm gonna re check all the valve clearances but is there something else that could cause this? I'm worried about anything going on in the bottom end!
The bike is a 1984 xj650!
Cheers!

 

Make sure that all the screws that you got loose are torqued to spec. Also check any parts that you may have loosen up to get to the valve cover.

 

What he ^ said. Also check for missing or loose exhaust stud nut. FWIW there are no '84 650's.

Gary H.

 

There are 1984 XJ 650's. They were not sold in the North American market, and went out of production in '85.

 

Go figure. I thought something like that...well you know, right after i posted. Thanks for the info. Where's the "delete" a post button?

Gary H.

 

Don't delete. Own your mistakes. A lot of people have learned from mine


Back to the matter at hand. Is the noise like a rythmic tap, or is it more staccato. like a chain rubbing?

When you did the valve adjustments, were any shims changed on the right side? Did you make sure that the shims were fully seated in their buckets before putting the valve cover back on?

 

I did change most of the shims, I noticed this noise before I did the shim job but was and is intermittent. The best way I can describe it is that it sounds like metal rattling but doesn't seem to do it constantly. I will re check my shim job for sure as soon as I get a bit of time to do so. Is there anything in the lower portion of the engine that could cause what I've described that I could check or test fairly easily?
Thanks

 

As far as the year, I questioned the ownership when I first got it cuz when I typed in the year at online parts places I couldn't find my bike so I learned how to decode the VIN and apparently I have an 84' and I am from Canada! Who knows where the bike was purchased tho!

 

Gonna attempt to post a video!

What is this sound?:

 

One of two things: one of your valves (I'd say an exhaust valve because the sound is louder in front of the engine) is now too loose because you put the wrong shim, or you have a blown out exhaust pipe gasket causing a leak right at the engine. Both give similar sounds.

 

Blowing exhaust gasket on the right?
or
Cam shaft end float which has become more pronounced now the valves are in spec? Is it slightly louder when on the side stand?
Does the tapping go when you increase the revs above 2k?
A mechanics stephoscope or long scredriver held to the ear should help narrow down where its coming from.
My 550 has a noticable but intermitant tapping that disapears above 2k revs. It started this when the valves were put in spec (the engine was way to quiet before). Ive checked and double checked valve clearances, the cam chain, exhaust gaskets etc. There was a Yam bulletin years ago about excessive cam end float and how a better machined centre cap was the cure. They also said only to do it if the customer complains, it has no detrimental effect on the bike. This applied to both 550s and 650s.

 

Well, I really don't think that it's the shims because I went smaller and the noise wasn't there before! I will check for exhaust leak, can anyone recommend a good way to do that? I'm thinking to just spray something while running!

 

If you have a punk left over from lighting fireworks you can use that. The smoke will visibly blow away from the leak when you get the smouldering punk near to it.

 

It doesn't sound as bad when I hit 2500 rpm !

While revving!:

 

I don't even know what a punk on a firework is! Lol

 

A punk is a stick made of material that smolders (males a fair amount of smoke too) instead of burning. You can use a blown out match or candle as well.

Listening to the video I hear a very rhythmic tapping, which is indicative of the camshaft endplay TSB that was referred to earlier. If it were an exhaust leak the noise would not be covered up with an increase in engine speed, instead it would get louder.

My 750 has the same tapping, and I know that the camshaft endplay is near the outside of the specified limit, so from my perspective you are good to go; nothing to worry about. Your idle speed sounds high to me though.

 

This is good news as I'm not quite as worried now but a little annoyed cuz I like a nice smooth sounding engine! Idle speed is a little high, I seem to always be playing with it! Thanks a bunch for the input man!!
Cheers!

 

"Well, I really don't think that it's the shims because I went smaller and the noise wasn't there before!"

Smaller shim = more clearance = more noise.

Remember these valve specs tighten up rather than loosen (unless there are other issues!) so by fitting smaller shims you will increase the valve train movement. This would (well I have convinced myself anyway) allow more movement/endplay in the cam itself as a by-product. A tiny amount, granted, but enough. I bet if you put all the old shims back in it would be as it was before. I was so paranoid with mine that I even dropped the oil expecting to see chunks of metal or at least glitter in the oil. Of course there was nothing.
Tight valve clearances will make the engine nice and quiet right up to when it burns a valve out

I would go along with what k-moe said and dont worry about it if the bike otherwise runs fine.

 

The smoothest engine I've ever had the pleasure to operate was a 1978 Mercedes diesel. Valve clatter can be a very sweet noise to hear, and that engine provided a symphony of clatter.

 

Lol! I had an old honda car like that also!