Run engine without the header?

(2010-06-03 23:50:22)

1. neal Says: Is there any dangers in running my engine (for a few minutes) without the exhaust manifold. I realise that it will be hell noisy and flames may shoot out, anything else I should be wary of?

just a little background info, I have a yamaha xj600 seca 2.

600cc, 4 cyl, air cooled, carbureted with DOHC.

2. biker Says: nope, should be ok for a short burst. Too much and I suspect you'll get the valve seats burning out or the like.
Having said that, too much and you'll go deaf and the neighbors will come round with a shotgun so that sort of limits how long you can run it :)
bd

3. jeff r Says: hard on the valves as well as the noise and flames. if it's enclosed, it might melt the plastic of over heat the motor

4. Travis Says: It can be bad in ways and yes it will be really loud. But make sure you don't do it in a cool environment and make sure you have good ventilation. But if you start it when it is like below 80 degrees outside then you risk the chance of ruining your valves and piston rings. But it will be just fine to run for just a couple of minutes.

5. 92_EG Hatch Says: i think mess up ur rings or maybe it was the valves
i no its not good