I just got my '03 RK in mid-September. It had just shy of 11k miles on it, and I wanted a good startup foundation, from which to do my own wrenching, so, I had the Hundred Dollar store do a full 10K service, and put new tires on front an rear, as well as brake pads on the rear. That was some serious green, on top of what I paid for the scooter in the first place. Anyway, I told them I wanted synthetic in the engine and tranny and dino in the primary. They went ahead and put syn3 in all 3 holes :newsmile055:
The tranny really felt tangibly under-lubed. When shifting up, it would only mesh properly at certain rev/speed combinations, and clunked badly. When shifting while getting on it, I had to be pretty authoritative to make sure I got good meshing. Down-shifting, I had to be below a certain speed, for each gear, or it would clunk like mad.
I just did my 1st 3K service, on my own, for this scooter. Syn3 is history! I stuck with the HD filter, put Mobil 1 V-Twin 20-50 in the engine, Formula+ in the primary, and Spectrol Platinum GL1 in the tranny. The Spectrol made a night and day difference in the tranny. No more meshing issues, and shifting clunk is greatly reduced, down to what I have been used to on my previous scoot.
One good thing about the Syn3...there was nothing on either magnetic drain plug. Frankly, I expected 1/2 the gear tips to be present as filings.
I am a bit concerned about oil capacity. The service manual says 4 qts for the engine. I put in 3.5, then took a 10 mi run, and did the hot check. She took the rest of the 4th quart, and still only reads midway between the add and full marks on the stock dipstick. I am using the HD LCD oil temp/level dipstick and it says full. Which do I trust?
Enjoy,
Rich P