Rattling/whining noise on XJ650

Hey folks.

So a week ago, I picked up an old XJ650 Seca 1983, with 50k miles / 80k km. on it.
There's a rattling sound there that doesn't sound normal, to me at least.. but hey, I'm a newb when it comes to working on bikes.. The sound is there whether the engine is cold or warm. I don't know how to describe the sound, so I uploaded 2 videos (one with a cold engine, and the other warm). The sound also only seems to be noticeable at idle RPM..

Other than that, the bike runs good. The choke has to be on for a good while when the bike is old, otherwise it'll die, and it's lacking some pulling power at the top end. But I suspect that has to do with the carbs which I haven't gotten to yet.

I don't know the service history of the bike, so the first thing I did when I got it home was to get a haynes manual and then go to work.. So far I've done the following:

changed the oil (20w-50 motorcycle specific oil)
changed oil filter
changed spark plugs
changed the gear/drive oil
cleaned out the old air filter
checked the valves too, 2 valves were out of spec so they got corrected.

Next job is to clean the carbs and get them synced, but I'll need a buddy to help with that.

Cold engine: (first 20 sec is with the choke on..)
Warm engine:

 

Freddie welcome to the forum. Sounds like blowing exhaust gaskets at the header pipes. Check all of the exhaust system to make sure you don't have and loose rattling parts. Also make sure you have no gas leakage where the headers enter the collector box and the box connects to the silencers.

 

Hey Franz

Thanks! I didn't think of that. Will check tomorrow and post back. I have a spare set of exhaust gaskets laying around somewhere, just in case.

 

You can tighten nuts to spec before replacing the gaskets and see if that does the trick. Something like 7.2 or 7.5 FtLbs (convert if needed) I think.

 

Read This First

Welcome aboard.

 

Hey k-moe

Thanks!

A valve clearance check has already been done. Two of the valves were out of spec, but that's been fixed now. And thanks for the link, I'll read that.

 

Ok, I've checked the header nuts and they're tight enough. Sound must be coming from somewhere else.

 

Not necessarily. The gaskets may be blown where no amount of tightening will fix. To be sure, hang something light like a feather on thread in front of each header to check for leakage. You want to eliminate the possibility before moving on.

 

Good idea, I'll try that and get back to ya. Thanks

 

Do what Huntchuks stated at the header to collector box and collector box to silencer joints too.

 

I just thought of another way. Deer hunters use a little squeeze bottle of fine powder they can puff into the air to detect wind direction. Maybe blowing some flour in front of the pipes would be an easier way to detect an air leak.

 

Ok, I tried it with a feather and it did seem like a little bit of air was leaking out. So now I've removed the exhaust, but the old gaskets have completely disintregrated and burnt stuck. I tried gently removing some pieces with a flat screwdriver, but I'm not so keen continuening like that as I'm afraid I might damage something. Any tips on how to remove the old gaskets? Looks like the aluminium + fibre type gasket..

 

Two or them came out fairly easy. Used a flat screwdriver at a 90 degree angle and "pushed" it loose, then pulled it out with a pair of pliers.

But the other two are a pain in the butt.. the fibre part of the old gaskets is stuck on very well, as seen on picture no. 2 above..

 

Use a pick or screwdriver and pry out and clean around port . Just be careful to not get crud into cylinder. Order new gaskets they are cheap , but noticed your from Denmark , so I know the xj was popular in Germany, this might be a good source .

 

Got the remains of the old gaskets removed, cleaned the ports up and installed some new gaskets. Don't really hear a difference though, but maybe it's just me..

I tested again with a feather and some light plastic foil and there's definitely no leaks at the header gaskets anymore.

 

The " noise" is there alot of moving parts , the camshaft, the chain , pistons crank shaft , both of my Seca's make noise . Valves that are tight or loose all can contribute..to sound.

 

Thanks. Maybe I'm overthinking it. My previous bike was a Suzuki VX800 and although that was a V2 it didn't have all of these sounds.. if it did they were certainly quieter haha.

The Xj650 runs good so I'll guess I'll stop thinking much more about it.

 

Your Suzuki was liquid cooled and this reduces the sound from the engine with the water jackets surrounding the cylinders.

 

That makes sense.

 

My Seca's both whine I like the sound...at least that is me