There seems to be a pretty nasty vibration comming from the forks when the bike gets in the higher rpms. i thought it may be the motor, but the bike still run good. what could this be'

No, it's the nature of the beast. Such an awesome bike but the motor is a hair shy on size and winds pretty high at 70. Get yourself some good padded after market handle bar grips, a better seat, and wear a mouth guard.
Were 2010's belt driven or shaft drive? If it's belt you could change the rear pulley and bring the rpms down a good 500 rpm which helps a lot, if it's shaft drive you're out of luck, you can't change the gearing ratio

if its valve chatter you will hear it just under the valve cover pretty pronounced, but usually valve chatter gets quieter as the bike warms up, you might look into your cam chain adjuster those get loud and chatty at higher rpms.

Not sure what bike you have, I'm guessing it's an 80's bike if it's got air forks. Usually the air pressure is in the 5->10 psi range, you don't need much. Really try to avoid putting too much pressure in them. As well as making your suspension too stiff, it increases the chances of blowing a fork seal. Also higher the pressure inside your forks will increase the friction of your seals. Not a lot, but every little bit matters when it comes to forks.

This is a pretty simple explanation and I'm assuming the oil level in your forks is already correct. If it isn't then you will be able to make it a bit better with air but it will never be quite right.

I have owned my 1500 since new, the vibration around 50mph I would say is normal for this motor..I think it is just the resonance of the engine at this RPM...On my own bike I replaced the U joint( which wasn't defective) wheel balance and brg problems eliminated,etc. As for the remaining vibration by pulling in the clutch and the vibs go away.Gagets stated in an
e-mail it could be rubber harmonic balancers in the engine that got brittle may be the problem..Also I think worn motor mounts may contribute to the problem. My only concern is getting stuck somewhere...My drivetrain is ok so I'll live with a little vibration until I have to take the engine apart for some reason.

you have to take the forks off and put the tubes on v blocks.. and with a dial indicator check the specs

spins but does not start

Hi,
Front end vibration can be caused by front rim/tire out of balance, worn wheel bearing(s), bent front rim, or fork misalignment.
Since you recently had fork work done, I would first check the forks for proper alignment, then have the bike on a stand and spin the wheel to see if there is wobbling. To check for bearing wear, while the front is off the ground, try to rock the wheel from side to side. If you can feel or see movement, you will need new bearings.
Hope this helps

The carbs should be synchronized every 20k miles. If you are having a roughness in idle then I would recommend the carbs being synched. If the problem is at higher RPM's I'd check to see if the motor has a harmonic dampener that can be adjusted. This often resolves vibration issues. I'm just not sure if this bike has one. These big bikes usually have some sort of adjustable dampening device internally.
I'd also like to have you check the motor mounts. This is a common problem if your bike has any rubber in the motor mounts. The rubber wears or even breaks and you often cannot see it until you actually try to remove the mount. Often they will fall apart in your hands.
These big motors all vibrate a bit so many of the manufacturers have realized that adding modified motor mounts is helpful.

Simply, it might just be the road... But, is it like a constant vib. that get worse as speed increases? And...what have you done with the motor that might have caused anything to go wrong? (i.e. kept it in a low gear at very high RPMs for a long period of time) Give me some clues...

i had this problem with my cherokee your not getting the right fuel mixure