I assume you do mean at certain speed [moving vehicle] if this is the case then I would say the normal problems that cause vibrations, wheel balance, worn tie rod ends or other front end conponents, even brake system, And not your engine at all. Now if it is in park and shakes at different rpms then I do not know the answer, I have never seen a engine shake unless it was when you first start it and its just warming up
if this happens at a certain speed it's probably the alignment of the tires.
It could just be the AC compressor causing the engine to shake when running at lower speed. If it's any more than that, the engine might need a tuneup, motor mounts or possibly a burned valve.
The pistons are running in the cylinders of the engine, so when the rpm of the engine rises, the pistons quickley build up speed. It is this rapid acceleration of the pistons that casue the car to shake.
One possibility is you might have one bad tire or a u-joint.
Wheel balance or drive shaft balance. Could be bearings also.
You will feel the steering wheel shake or judder in your hands at a certain speed. You will usually find it is ok at a lower speed then you feel the steering wheel shake as you accelerate and then disappears again as you go faster. Usually the shaking appears at exactly the speed you want to go (Murphy's law)
Sounds like either you have a bent rim(s) or your tie rods are going.
Thankfully mine does not shake, thanks for asking. This is really not enough information to diagnose the problem. Does it shake the same every time or does it not shake or shake less sometimes? Is the "check engine" light on? Is there a speed where the shake is more pronounced? Does it have to be full throttle acceleration or does it shake under light acceleration too? Is there a noise accompanying the shake? If you accelerate around a corner is the shake any different? Left or right turn make a difference?
The 1995 Suzuki RF900R does not have a traditional speed governor like some vehicles might. Instead, it is designed with an electronic rev limiter that prevents the engine from exceeding a certain RPM, which helps protect the engine from damage. This limiter acts as a safeguard rather than a governor that restricts overall speed.
By safe shutter, speed I assume you are wanting to know the slowest shutter speed that will not capture noticeable camera shake? There is no absolute answer to this. How much do your hands shake? The 'rule of thumb' I have used is 1/{focal length}. For a 400mm lens you would need a 1/400 sec or to use a tripod to avoid noticeable camera shake. For the 18mm you might get away with 1/20 or so. Although I despise using tripods, they will always give a sharper picture. You might need a microscope to tell, but you can tell.
It is important to know the causes behind warning lights showing up on a car. The check engine light comes on after a certain speed because there is a problem with fuel, electricity, or oil of the engine after that speed, that is causing issues.
rev limiter, engine will sputter when it hits this limit to keep engine from over reving