450cc engine details

[Siddharth Mandal]

could anyone please send us the specifications of yamaha wr450i and also its
maximum power output
power output after the 20mm restrictor
gear ratios
maximum torque
maximum rpm..etc
its difficult to find such details in my country we would be very grateful

[Siddharth Mandal]

could anyone please send us the specifications of yamaha wr450i and also its
maximum power output
power output after the 20mm restrictor
gear ratios
maximum torque
maximum rpm..etc
its difficult to find such details in my country we would be very grateful

[Big Bird]

A few ballpark figures to get you started (I don't have all our data in front of me right now, but this will be good enough for initial benchmarking)

We first tested our WR450 at around 45 hp (unrestricted) with the standard carbs. Development of the EFI and associated tuning saw this rise to around 55hp (restricted). The restrictor itself doesn't really affect the output a great deal. I don't have torque figures or gearbox ratios on me, rpm range up to around 10,500. Engine weight approx 29kg.

If you are thinking of trying for a small single, don't fall into the trap of designing on engine output only. If you judge purely on the basis of forward acceleration you would never choose it - the advantages come in reduced size, weight, packaging, manufacturing and development time. We were more than happy to trade off some straight line acceleration for these benefits.

Good design is not about having the most of everything. It is about understanding and assessing the trade-offs inherent in vehicle design, and then setting a direction that best suits your own abilities and resources.

Hope this helps,

[Nitesh]

Hi siddharth

Which college are you from?

[damonlemmon]

does anyone have a cad model for the yamaha wr450? need engine mount locations. thanks