F500 rev valves

[Captainrags]

As I progress with my restore and education of the 500, I see there are no rev valves nothing just holes however the engine did run briefly with easy start fluid.
So my question if any body can direct me, are they nesary rev valves and why are they not there also looking at the oil Injection pump below the carbs there is no cable just a wire tie loosely tied off.
are the valves a variable standard or performance? The oil pump has no cable looks like it might have been bypassed and a fuel oil mixture used instead.
Is the 494 also called the 500.?
Any help is always appreciated.
Thank you
ray weldon

[mark 21]

[QUOTE=Captainrags;620399]As I progress with my restore and education of the 500, I see there are no rev valves nothing just holes however the engine did run briefly with easy start fluid.
So my question if any body can direct me, are they necessary rev valves and why are they not there also looking at the oil Injection pump below the carbs there is no cable just a wire tie loosely tied off.
are the valves a variable standard or performance? The oil pump has no cable looks like it might have been bypassed and a fuel oil mixture used instead.
Is the 494 also called the 500.?

The 494 is the model number of the motor you have. 500 is the class the car runs in. The 494 came in two versions. the non rave version witch you have.The non rav motor there were alot more made then the rav version. The rav version was only made i believe for two years and were not put in all the model snowmobiles the 494 was in. The rav motors were made to help the motor have low rpm performance. It lower the high of the exhaust port at low rpms help the snowmobiles performance coming of the line from a dead stop. The rav motor has a different head and different rotary valve then the non rav non motors. But the rules state that if you run a rav motor you are to run the non rav head and rotary parts in that motor.

[Jnovak]

[QUOTE=mark 21;620401]

As I progress with my restore and education of the 500, I see there are no rev valves nothing just holes however the engine did run briefly with easy start fluid.
So my question if any body can direct me, are they necessary rev valves and why are they not there also looking at the oil Injection pump below the carbs there is no cable just a wire tie loosely tied off.
are the valves a variable standard or performance? The oil pump has no cable looks like it might have been bypassed and a fuel oil mixture used instead.
Is the 494 also called the 500.?

The 494 is the model number of the motor you have. 500 is the class the car runs in. The 494 came in two versions. the non rave version witch you have.The non rav motor there were alot more made then the rav version. The rav version was only made i believe for two years and were not put in all the model snowmobiles the 494 was in. The rav motors were made to help the motor have low rpm performance. It lower the high of the exhaust port at low rpms help the snowmobiles performance coming of the line from a dead stop. The rav motor has a different head and different rotary valve then the non rav non motors. But the rules state that if you run a rav motor you are to run the non rav head and rotary parts in that motor.

Actually the 494 was originally required to use a specific lower hp rotary valve but this is no
Longer required now that the 600 2 strokes and 4 strokes can run together. I suspect that it is not possible to make any 500cc 2 stroke engine competitive with any 600cc engine 2 stroke or 4 stroke.

[cory mcleod]

@Captainrags - Did you get my PM?

Cory