Sticky throttle in cold

Took short ride yesterday in 38-40f temps. Had to manually roll off throttle after about 10-15 minutes riding, very uncomfortable feeling! So brought it home and put in garage. Today temps are in the 60s. Not riding but pulled out of garage. Throttle now snaps back without hesitation sitting in sun. What would be causing this? Does throttle need to be dismantled and cleaned/lubed etc?
Just dropped $$ for carb clean/oil&filterhange/shaft oil change/rear brake inspection, looking for safe inexpensive fix.

Thanks!
Brian
1982 xj650 Maxim coming into first full year of ownership!

 

Mine did that when I tried it this winter. It must have been 20 degrees in the garage. It doesn't do it when it's normal riding temp outside though 45+. The carbs were rebuilt in 2008 and I drain the bowls before it goes into winter storage. Could it be different materials in such close tolerances at too low a temperature? I know you can see the valve clearance change drastically from near engine operating temp vs 30 degrees. Interesting.

 

Draining the bowls prior to storage is asking for varnished up carbs. You cannot get every trace of gasoline out, what's left in there will turn to varnish more quickly now that there's all that air in there too.

More likely OP's issue is simply mechanical; the throttle assembly (at the grip) probably does need to be cleaned/lubed.

Cowboymav did the shop also check and adjust your valve clearances? It needs to be done every 5000 miles and was often overlooked. Plus you really need to check the date codes on your front brake lines.

 

Mine was doing that this last winter, the handle bar under the twist grip need to be cleaned and lubed.

 

Fitz, no valve adjust, was done last season. Saw a separate post on brake lines :-(. 8/81 is date. Time to look into SS lines.
Razz, what did you use for lube? Is the cleaning any more involved than removal and wipe down of bars with a solvent like alcohol?
Thanks!

 

Mine was pretty rusted (mine is driven rain or shine) so I sanded it smooth then used a dry Teflon spray. Slicker than snot on a glass door knob.