dawood74

Gents,
does anyone has an idea whether removing and operating the engine without the rocker cover would effect, i lost my YS110 rocker arm cover and i cannot find it anywhere !

MinnFlyer

My Feedback: (4)

On YS engines you MUST have the rocker arm cover in place

dawood74

where can i buy it from ?

MinnFlyer

My Feedback: (4)

http://www.centralhobbies.com/Engines/parts/ysparts.htm

Gray Beard

My Feedback: (-1)

There is also a YS support here on RCU that can answer all your questions about there engines.

w8ye

My Feedback: (16)

The Y-S engines will not run without a rocker cover.

It will not run very well if the rocker cover leaks

Saito, OS, and Magnum four strokes will run all day without a rocker cover though it is better to have one.

LouisB

Would imagine that the cover prevents the airstream from removing upper-lubrication?

MinnFlyer

My Feedback: (4)

YS engines have a pressurized system. The area under the valve cover is part of that system. Without the cover, the system can't pressurize and the engine will not run.

I learned this the hard way when one of my rod covers got knocked out of place and allowed the pressure to escape.

w8ye

My Feedback: (16)

The area under the valve cover is used as a plenum chamber for the intake manifold. The area stores air-fuel mixture that goes into the combustion chamber when the intake valve opens

The engine will not run without a firmly attached valve cover

There are holes drilled around the valve guide from the valve cover area to the intake valve pocket so if the cover is removed, the intake fuel-air mixture escapes out into the unknown

Jetdesign

My Feedback: (8)

Don't forget a new gasket. Unfortunately it is only available in a gasket set for $12 or $14.

Gray Beard

My Feedback: (-1)

Joe, are you sure about that?? It seems to me I ordered some extras with my extra Diaphrams?? Icould be wrong about that though because I have had gasket sets here in my shop for different models of engines.
Inow order from YS Service unless I need some items sold through Central. Maybe Iwas able to get some rocker gaskets from them??
So much for that memory like a steel trap, Ican't remember what I just had for dinner!!