750 SECA goes: WURRRRR…?

This bike is running great, but since I got it running it's always made a wurrr sound like an electric motor, but a little loud. :? It only makes the sound under load, not when idling or decelerating. I think it's the cam tensioner. On this bike it's a nonadjustable automatic tensioner.
It's not coming from the differential gears.
Anybody else have a 750 SECA that make this noise?
Thanks! Bill

 

my xj700 does it. it's gear whine
different oils make it louder or quieter

 

It's from the primary in the crankcase I believe.

It's commonly referred to as middle-gear-whine, but that is untrue.

550's don't have it because they have a chain drive primary, and all the others are geared.

Am I right guys? Haven't been on here in months but I think that's right.

 

maybe the whine your thinging of could be the shaft drive or the yics, those both make some whines, now if only there was a chees compartment...

 

My '81 Seca 750 sings to me also.
I had a local mech who is touted as being an in line four guru take a listen and he said it was all good. Just normal noise that may or may not get louder as the top end loosens up. I am about 6k mi. past due for the valve shim checkup and still running great.

 

the spool up sound is the middle gearing. it is a common sound on the shaft drive bikes, especially ours

 

my 85 xj700 also makes the whine

 

actually, I love that sound

 

Get the shims checked, seriously.

The valve train on these bikes tightens as time goes on - so NO NOISE is bad. Noise, to an extent is good.

If the shim has excessive space (also excessive noise)
- you can spit a shim out.

 

lol i like the sound too. it did it on the bike since my dad owned it and i always liked it

 

it may be the final drive..

if it is... and assuming you want it a bit quieter

i used Royal Purple 75-140w in my xs11 mid and final drives..

I'm not sure about your XJ tho... please get a second opinion on this.

it worked great on the xs, you can't hear the drives anymore.

i know it will be fine in your final, but do the XJ's have mids with seperate oil?

Webs..
(sorry my xj's are still hanger queens)
i haven't had much time to work on them, or learn they're systems.

 

So with the valve noise (sewing machine), middle gear whine (sounds like we're in reverse), and the clunking into first.....

 

haha... right on Joshua.

No, Webs, the XJ's don't have mids w/ oil.

The 'whine' most people refer to, that they only hear under load, is the primary gear whine. Straight toothed gears if I remember right.

550's use a primary chain, no whine.