My wife's 85 lt250r has an fmf exhaust and boysen reeds and supposedly had the ports cleaned up.would getting a port work make much of a difference with this year quad.

It will make the same difference now as it did in 1985 when they were new.  The big question is:  what type of power level or what bike are you expecting this ported quad to  outperform?

It will take more than just porting for the 85-56 to outperform the 450 four strokes that has a good pipe and a good intake/air filter setup.

How far you want to take this engine depends upon your budget.

It will take the "right" porting, head mods, piston mods, a larger carb, a better pipe to get this engine up to 43 to 45 HP.  An engine at this level will not run on pump gas.

We aren't sure what we want to do to it just seeing if the amount of money that had to be put in to it to compete with 450s is worth it or just leave it the way it is and get an 87 to 92 lt250r.what would just a port job do.would that be with doing just that. 

Doing just a port job on a 85-86 will raise the power level a similar amount as just doing a port job on a 87 to 92. 

It will cost about the same to raise the power level of either engine to be competitive with the 450s.  Unfortunately there is not a Santa Clause, a Tooth fairy or one magic modification that will raise the AVERAGE power level of any of the 250 two strokes with the AVERAGE power level of a 450 with a few bolt-ons.   

Unfortunately, the 85-86 motors are limited when it comes to aftermarket parts.
Porting, larger carb, and pipe will make a difference.

However, due to the small intake it has it's limitations.

Don't get me wrong, you can make it run pretty good!
I did a 8mm "Long Rod" not a "Stroker" mod on mine and it runs very well and is reliable.

I did the mods myself so, it saved me the shop service labor.
Good Luck!

Joe