Seca 750 whine

Very nice Seca 750. 10,000 miles, carbs professionally cleaned and adjusted, fresh oil change with proper motorcycle oil, valves checked. Bike runs like a brand new motorcycle. Problem is there seems to be what sounds like gear whine. I don't know if it's coming from the engine or drivetrain.

Do these bikes have this sound? It's the first shaft bike I've ever had. The sound seems excessive to me.

Any hints on where to start troubleshooting on this?

 

The rear diff can whine ..have you checked oil level? Another possible whine is the speedometer put you had an cluster at around 30 miles per hour see if vibrates if so that could be issue. Unless it is so loud you need ear plugs ...just ride.

 

It is pretty loud. I haven't checked the rear differential, what oil should I put in there if it's low?

 

could be the middle gear whine, it has to do with the driveline doing a 90 to spin the driveshaft. some bikes do it more than others. there's nothing you can do about it, doesn't hurt anything.
there's also a middle gear clunk that has to do with springs and mechanisms that replace the cush drive on a chain bike. feels like someone kicked the back tire when you start out. disregard that too.

 

The motors whine too because of the chain driven alternator (or so I've read). Does the whine increase with the speed of the bike or with the RPM's of the motor? If with the motor RPM, its the engine like shown in this video (again this is normal sound).

 

Good video.

How about giving a clip of yours if yours is drastically different?

 

I rode to work today and was paying more attention to the whine(s) way more than usual. There's definitely a drive whine too from the gears. Both are normal though.

Ditto

 

Mine has similar whine, but, my exhaust is somewhat louder (not intentional - item 126 on the list of things to tinker with)

 

My Maxim 650 does it, totally normal for these bikes. When you first get one of these old XJs and read about/drive them you quickly learn they made a lot of weird yet normal noises

 

Yup, perfectly normal.....and COOL. You can hear one coming a mile away. literally. It's really fun at a carb clinic to see a bunch of guys working on bikes, other bikes going by on the road....and then all of a sudden some heads will pop up and someone will say,"here comes one"..........sure enough, about a minute later, an Xj slows down and pulls in. Gotta love that whistle

 

My xj700n has a whine and I have been trying to track it down. You can only hear it when accelerating and it disappears around 3000 rpm. It is nowhere near as bad as the bike in that video.

 

Paul, that's a NORMAL sound

 

The cooling fins on the engines tend to whine on acceleration thats what all those rubber inserts
stuck between the fins are for.

 

They don't whine, they sing (like a xylophone).