I let a friend borrow my bike and he had a new tire put on back it is a 170/80-15 and now the tire rubs the stabilizer bar and if you adjust it off the bar then it rubs the chain is this tire bigger than the original 150/90-15 or is there something else that can be done?

A question often ask and much disregarded
although the tow bar weight is within limits
the load distribution bars ( torque bars -stabilizer bars --sway bars etc) not only help distribute the load but act in such a way as to stop the trailer /caravan for developing the sway that tends to make the driver loose control at speed
they also , when properly adjusted, keep the ride height of the towing vehicle level and that improves stability
remember that although the bar weight is 175 kgs that amounts to a load of 525kgs over the rear axle or extra 525 kgs on the rear tires ( mass multiplied by distance from drive axle or rear wheels assuming the distance from the axle/tires to the tow ball is i meter---heavier if the bar is further back from the tires )
to use the distribution bars lifts that weight off the rear axle and places more of the load on the trailer wheels
As a result the car / trailer combination is much safer to operate than without the bars

You have damage to the front area brake system. It could be very serious but if car stops OK most likely not that serious you just won't have abs or traction control. The damage is most likely a speed sensor or something similar. I said it could be serious that is only worst case.
Here is a breakdown of what lights mean
ABS keeps your breaks from locking up
BREAK ASSIST helps your breaks
Traction control if you one wheels spin more than others system adjust wheel spiN

Most likely the back wheel is out of alignment.
With the front wheel held (exactly as possible) straight ahead.
From the back you can sight along the outside edges of the back tire on each side, as high up as you can for better accuracy.
You can use a long straight edge instead,
It should be the same amount wider than the front on both sides, get a friend to hold the bike vertical and another to hold a ruler or tape measure on the side front tire where you can see it.
This is very important to handling as well. The manufacturers marks on the back axle adjustment points are not always accurate.
The front and rear pulleys should also be perfectly aligned.
If the wheel alignment is okay then yes the tire could be too wide.

Hi put your bike on the side stand get some blocks or something to put under the frame as far back under the frame tp lift the rear wheel off the ground spin your tire maybe the mechanic adjusted the rear wheel off center and its rubbing the fender, swing arm. or belt guard.

Remove the side cover nuts and the cover, wind the bar adjuster screw fully back, it may be in the cover, or on the front of the saw, push the guide bar fully back toward the sprocket, loop the chain ocer the sprocket and lay it around the the guide bar, make sure the cutters on the top of the bar rail are facing away from the saw, this will make sure it is the correct way round make sure the bar adjuster pawl is engaged into the hole in the bar, if the adjuster pawl is in the cover, replace the cover making sure the pawl engages into the hole in the bar, refit the cover nur finger tight, adjust the adjuster screw so as the chain fits snug fully around the bar, loft the nose of the bar and fully tighten the cover nut, with a gloved hand pull the chain manualy around the bar to make sure it is fitting in the rails and the sprocket correctly.

Removal & Installation

1. Raise and support the vehicle.
2. Remove the tire and wheel.
3. Remove the stabilizer shaft nut from the link bolt.
4. Remove the stabilizer shaft link bolt.
5. Remove the stabilizer shaft link insulators and spacers.
6. Remove the oil pan skid plate, if equipped.
7. Remove the stabilizer shaft insulator bracket bolts.
8. Remove the stabilizer shaft bracket.
9. Remove the stabilizer shaft.
10. Remove the stabilizer shaft insulators.
11. Inspect all of the parts for wear and damage.

To install:

1. Install the insulators to the stabilizer shaft.
2. Install the stabilizer shaft.
3. Install the brackets over the insulators and the stabilizer shaft.
4. Install insulator bracket bolts and tighten to 37 ft. lbs. (50 Nm).
5. Install the stabilizer shaft link insulators and spacers.
6. Apply Loctite® on the threads of the stabilizer link bolts then install the bolts.
7. Install the stabilizer shaft nut to the link bolt and tighten to 89 inch lbs. (10 Nm), and continue to tighten the nut until 2-4 threads protrude above the nut.
8. Install the oil pan skid plate, if equipped.
9. Install the tire and wheel assembly.
10. Remove the safety stands
11. Lower the vehicle.

Did you change anything ... like putting stuff in a saddle bag? Different boots? Have you cheked air pressure in the tires? Are you sitting on the bike differently?

I'm leaning to tire pressure or uneven front tire wear and it does not have to be a lot of uneven tire wear to act in thismanner.

Please my friend, get this looked at by your Yamaha professional

Thanks for posting at FixYa.com

please vote

a

Try just bending the belt guard or removing it and fileing some material off the guard so it does not rub. You may also be able to remedy this by adding washers to the belt guard attach points.

is it rubbing all the time when you spin the wheel or is it as if the wheel is buckled? or could it be bearings in your wheel. (any side to side movement in it) if not then gotta be tire not seated correctly, you will see this though if you examine it along the rim on both sides, OR the shop put a tire on that was too wide, with either of these tire problems i suggest you go back to the shop that installed it, to re seat it you will have to remove the wheel and deflate tire fully, break the bead seal against the rim. then re-inflate carefully to seal it against the rim, give it a few bounses to help saeting correctly.