If the tempeture drops say 10 degrees you can loose SOME pressure (not as much as you report)
Grump gave you the list I'd give you... start at the stem, then around the outside,then the rim, and finally the tire itself

Do you have cast wheels? or laced wheels? if laced, are all the spokes tight? seems like a pretty easy thing to check on your own.... if all of the above come up empty? bring it back to the dealer, and be positive, and friendly with the service manager...... you know, "catch more flies with honey, than vinegar".

I check my tires weekly, I know I oughta check them each time I ride, buy so far,[knock wood] the cast wheels, and Dunlop E-3's haven't lost a bit.

good luck

 

If I remember right pressures drop 1 pound for each 10 degrees, that's why nitrogen is used in tires that are critical to pressure drop. I would check the valve cores. If you want to take of that and you don't have a core tool Autozone does and they have the valve cores also. Cheap!

 

Thanks for the suggestions. Yes, I'm aware of the pressure fluctuations with changes in temperature. I keep my bike in my attached garage where the temperature doesn't fluctuate too much. Also, I do the pressure checking in the afternoon just before taking a ride, so the temperature shouldn't fluctuate too much. If it's cold (below 60*), I seldom take a ride.

I think I'll check for leaks around the valve stem. If I find a leak there, I'll know to mention it to the dealer when I take it back. If the leak is elsewhere, I'll let them find it. I agree that the dealer should take care of the problem. I just wondered if others agreed with me on that.

BTW, the bike has cast wheels, not spokes. See the picture below.

Thanks.

 

I have a very slow leak in a tire on my riding lawn mower. I thought I'd never find it. I had to submerge it, and it turned out to be a star thistle embedded in the tire. Even after submerging, the little bubbles came so rarely that I almost missed it. The tire will hold air for two or three weeks.

Since the tires are tubeless, and since I'm apt to hit more of those thistles, I just ordered a gallon of Slime to do all of the tires. I would never do that on a motorcycle, but mountain bike riders use it a lot.

Point is, a slow leak can be very hard to spot. Good luck.

 

check you valve stems

 

+1 just go get the tool & new valves. One of the o-rings on the stem valve could be old and leaking. I would just replace them to eliminate that possibility. Just take the weight of the bike off the tire when replacing.

 

http://www.ride-on.com/prod_mot.asp

 

Have seen crack in casting that would leak down to a certain pressure and stop leaking. Keep an eye on the rim area while checking for leaks.

 

UPDATE:

Well, I called the dealer again today. I first called them about this problem two weeks ago and the guy in the Service Dept said to fill both tires with the proper amount of air pressure and then check it daily and get back to him.

When I called today, I talked with a different guy in the Service Dept. This guy, Dave, didn't seem to think that losing 3 1/2 pounds of air in 13 days was any big deal. I told him that it was a big deal to me, especially for NEW TIRES. He said, "Yeah, but they were put on USED rims."

Further, I told him that I've had Harleys for the better part of the past 40 years and never had one that would lose 7 pounds of pressure in a month. Typically I will check air pressure every 2 or 3 months and before any long trips (which I seldom take). Usually there is negligible loss of air in 2 or 3 months. With this tire, it lost 18 pounds in 3 months........ and Dave didn't think it was a big deal.

Anyway, he finally said to bring it in and let them check it. Said it would take about an hour to check. I asked if I would be charged for checking the tire. He said, "No, not if it's something simple like a leak around the valve stem which they could fix. If there is a nail or something in the tire, then yes, I would be charged."

I replied that was OK with me. So I'm supposed to take it in Thursday afternoon. I'll let you know what happens.

 

I don't think this is a big deal either. Tires are air permeable. I haven't ridden for forty years, but I've been around tires (inside and out) of all sizes for twenty-five years, and they all lose air to a varying degree.

Still, I hope they work it out to your satisfaction.