Hello all, about three weeks ago, my 12 year wait for a 907 was finally realized. Back in 1998 I missed a used red 907 by about three days, and ended up with a brand new 900SS, grey in color, which was soon repo'd, due to loss of job. Alas, finally I have the one I originally wanted, a 1991 907, red in color, would have preferred black, but, red is fine! Got it for a deal, too, I have repaired the coolant problems, with a resevior from a 1984 vf 1100, and the cbr 600 radiator filler, and am now installing the 65 degree C thermostat, from an Aprilia, thanks to the info I found on this board. It was consistantly running at 250 degrees F, too hot for me.
I recently took it on a 200 mile ride, and nearing home, it was starting a storm, not raining yet, but windy, I noticed that it felt as if the bike was unbalanced to the left, a tractor trailer passed me, and I almost fell over. I thought it may have been due to truck ruts in the road and the windy conditions. The very next night, I rode it to work, some wind, not more than usual, and felt the same way, no truck ruts in road surface. Any suggestions on what may be causing this? repair of left fork? bad rear wheel bearing? the sprockets and chain are new, and installed by the shop I bought it from. Could the shock cause this? Swingarm issues? the bike has 26,500 miles on it. I am a capable auto mechanic, but, know little of bikes. I do exceed the recommended weight, any thoughts on how to compensate? I wiegh 350 lbs. Thanks in advance, all help greatly appreciated!

Oh sorry I forgot to add, the ill handling only started within the last 5 miles of the 200 mile trip.

Hi there & welcome. A rather stupid question, is there enough air in the tires ?
My Paso started pulling in all directions when the front tire lost air due to a bad valve once.
(btw if chain & sprockets were just changed, be sure the left side conical spacer was mounted in the correct way, its larger side showing towards the swingarm)

G.

Your problem could be caused by many things. However, most times the simpliest fix works. In the last few months, my 907 was getting harder to steer. It seems harder to turn into a curve. Parking lot speeds were getting more difficult. The Pirelli Corsa Diablo's were getting near the point of replacement, but the front time DID have some tread left. Great tires.

However, I replaced them with Michelin Pilot Sport tires. WOW! All handling problems disappeared. I doubt if the Michel;ins were the panacea, but new tires, in general, were the solution.

thanks so far, it has the michelin new tires, proper air pressure, I will check the spacer now, but, I also forgot to mention that after replacing the fairings the rear tire was rubbing something, on the angled portion, which I thought was the reflector on the right side. When I noticed it, I had forgotten to make sure the black lip, that the reflector was mounted to was on the on the lip of the rear fairing, I popped it back into place, and no more rubbing (shiny spot on tire) but, that makes me think there may be a problem in the back. It is only unstable to the left, though, and only when trying to ride straight.

Now I feel bad, I just saw the edit button, The shiny spot (rubbing ) seems to have been caused by a misrouted hose (overflow?) the spacer seems to be in the right place.

I had this problem on an old z650 I had which was due to a bent frame. Nothing has broken has it, such as a weld?

Is the chain actually aligned proparly? Was it tightened up proparly so that nothing moved?

Are one of the front brake disks binding?

Did you hit a pothole, are the triple clamps/steering stem straight?

If it pulls to one side something is out of line. If it is a general instability then tyres (pressures if new) are the most likely followed by steering head bearings and swing arm bearings.

If you have new tires, maybe whoever put them on the bike didn't get them mounted correctly. Check the spacers on the front and rear. See the picture below. I would loosen the front axle and push down on the forks with just the axle snug and the two lock bolts loose. This could equalize the forks if someone screwed up. Check your brakes as someone else suggested. Brake dust builds up around the caliber pistons. Drain the fluid and take the calibers apart cleaning everthing. Put them back together putting some grease on the piston cups. Routine maintenace that many don't do. Michelin tires are the way to go. Ducatis are designed for them and them for Ducatis.

Thanks for all the replies, it seems to be an off and on issue, I finished the thermostat mod, earlier, then test rode to op temp, sans fairings, the handling was fine, granted I only got it up to 40 mph, i live in town. Stopped at the local piggly wiggly, for some distilled water to top it off with, and someone insulted me with an offer of $1000, for it! I explained that that would not even touch it, and the merits of this bike. tomorrow I will put the fairings back on, and give it a longer test ride. Checked for play in the front and rear, checked the chain, no out of place welds that I could tell, or breaks. Tomorrow will be an up to speed test, could have been more windy that I remember, or after the long ride I was tired, not as limber as I used to be, and had my weight shifted wrong? Anyway, I really appreciate all the advice, and responses!