Engine question: VALVES?!

[RBar]

Websites state that the GZ250 has a TWO VALVE head.
The Service Manual shows what appears to be 3 valve springs, and on the underside, two intakes and two exhausts! Are these pics correct for the GZ250, or are they using a different set of pics for the service manual?

The two exhaust pipes WOULD indicate something different about this single cylinder. "TWIN DOME" combustion chamber might be another clue...
Are the pistons domed? with the spark plug in the center of the combustion chamber, that would make it sorta like a little hemi engine, right?
ANYBODY every had theirs apart?

RBar

[Water Warrior 2]

The Gz is a single cylinder 4 valve engine. 2 intake and 2 exhuast valves. Each exhuast valve has it's own port and header pipe. The pipes join up in a single muffler system. There is a single carb feeding the 2 intakes.
At one time the GZ did have only 2 valves, one intake and one exhuast.
On the 4 valve head there is a single rocker arm with 2 fingers to operate the 2 intake valves and another rocker with 2 fingers to operate the exhuast valves. hope this helps.

[RBar]

EXACTLY answers my question, thanks!
So, each exhaust side has its own pipe...cool.

RBar

Originally Posted by Water Warrior

The Gz is a single cylinder 4 valve engine. 2 intake and 2 exhuast valves. Each exhuast valve has it's own port and header pipe. The pipes join up in a single muffler system. There is a single carb feeding the 2 intakes.
At one time the GZ did have only 2 valves, one intake and one exhuast.
On the 4 valve head there is a single rocker arm with 2 fingers to operate the 2 intake valves and another rocker with 2 fingers to operate the exhuast valves. hope this helps.

[geezer]

i thougth each valve had its own cam lobe. and when was the gz a 2 valve?

[blaine]

Originally Posted by geezer

i thougth each valve had its own cam lobe. and when was the gz a 2 valve?

Single lobe,double fingers.The engine was a 2 valve engine,back before the G.Z.
:cool:

[geezer]

i thought so, i have the first year of the gz and its a four valve.

[blaine]

Originally Posted by geezer

i thought so, i have the first year of the gz and its a four valve.

The Suzuki TU 250 uses the same engine with a 2 valve head.
:rawk:

[geezer]

the new one?

[blaine]

Originally Posted by geezer

the new one?

Yes,with fuel injection.A lot of the older bikes used the same engine,it's been around a long time.
:cool: