Why do motorcycles have more horse power than quads? I've noticed that engines taken off of dirt bikes to put into production quad (raptor) are designed to have less horsepower. this makes no sense to me. Quads have more weight, so they should have more power than a dirtbike........ the following engines were not put into production quads................The SUZUKI RM125 has 30.5 horse power. that is approx. 2hp more hp than a honda sportrax 400. This seems stupid. a 125cc motor has more HP than a 397cc motor. heres another one..... The Suzuki RM250 has about 45HP stock. That is a little more power than the ds650 and raptor, yet it is less than half the cc size. I know the two dirtbikes above are 2 stroke, but the 4 stroke's extra cc's should have made up for the difference. I guess my question is why do dirtbikes need more power than a quad when they weigh alot less?

 

The ATV manufacturers are too afraid of all the beaurocratic lawmakers that want to shut them down to really go all out and build an awesome machine. The government put an end to 3-wheelers in the late 80's and would like to end all ATVing. (Hopefully now that Bush is in office, that will not be an issue for a while.) On the other hand, motorcycles are more socially accepted for some reason and therefore the factories can do just about anything they want. I bet if you looked at the number of injuries per capita between ATVs and motorcycles, the motorcycle would be higher. I myself would love to see a full-on sub-350 pound yamaha racing quad with the unaltered YZ426 engine in it. That thing would scream. I am afraid it will never happen though.

 

Along with the political jargon. I think it has to do alot with cost.
There is alot more contact area(tire to ground) and weight on a quad. That equals a ton of stress on things like the frame/bearings and especially transmission. If a manufacturer were to make a high output quad that was light weight, the cost would be way to high for a consumer. So instead...they count on the aftermarket to provide us with the goods to go faster. In return...they sell alot of production units. Most people can't afford a 15000 quad right off the bat.... But mods add up quick. I do believe there is alot more to it. All and all most quads are provided with plenty of power for the purpose they were intended. Alot of people (at least most of the people I ride with) think they need 500000 horsepower to go fast. When in fact...they just need to learn to use the power that has already been provided.
At least thats my opinion...I could be wrong though.

 

Never say never...I have a yz426 motor and if I can find the right Banshee frame, the only mods will be the motor mounts and any minor design changes....If I get the frame, I will let ya know how it goes