I bought my son a Unison Desert Cat 50 about six months ago to learn to ride on. I also bought my daughter a Unison Desrert Cat 90 at the same time. Well as you can imagine my son picked up rather quickly and now would rather ride his sisters 90 than his "slow" 50. If you look at the two quads they identical with the exception of the wheel & tires and the CC's. The engines look identical and most the part numbers are identical. On the specs I noticed that not only is the bore bigger on the 90 but so is the strock. I was wondering if you can replace the top-end on these to convert to a 90 cc engine. I'm not sure of the cost, but it would have to be less than selling the 50 and buying a new 90. I am very happy with both quads and feel for the money it's a good deal. Any ideas?

 

Also, what kind of mods do they make for the 90 and do they really make a difference?

 

mods make a huge difference. Pipe, air filter, jetting and the right cam can add a potential 10 hp if you do it with the right stuff!

 

We also have a DC90 and love it. We were told that you can modify these bikes. The cylinder can be bored, you could probably add reeds, you can put a FMF pipe and muffler on it. Anything you can do to a little Polaris Preditor you can do to your Unison.

I don't know where you live, but try calling Rod at www.bumblebeeatv.com and ask him about mods for your bikes. I know he sold a bike to a kid that rides at the beach all the time and his bike has been bored to a 110 I think. Then you could just find a good bike shop in your area.

If your thinking about boring out the 50, do that before you add any of the other stuff. Or your other option would be to add a bunch of mods instead of the engine work. You can also take off the oil injector. I would probably try the oil injector, some reeds, maybe you could have it ported a little and add a new pipe.

I don't know, just some ideas for you. But do call Rod. We drove 5 hours to buy a bike from him. He is very nice.

Good Luck

B1mom
2002 Blaster
2005 Unison Desert Cat 90
1986 Honda Trx250r

 

Your 50 can be made into a 70cc bike and for not all that much money (under) $200 and will outrun the 90 easily. The most you can get out of them easily is about 75ccs and yes it will fly. Those bikes have no cam but most of the mods for the 90s will apply to the 50 like pipe,reeds, more compression, porting, clutching mods will do wonders. A 50 we race with is very close to the performance of the modded 90s. The unison is very easy to mod. Hope this helps.