engine code

[moose200]

hey guys i found this engine and im plan on dropping in, could you tell me what engine this bike is out of so if can find out if I need new jets for the carb,they look the same?

NEW ENGINE
gs40x-115524

ENGINE IN BIKE
k501-103580

[Nessism]

Need photos

My guess is 8 valve 400

[Mekanix]

hey guys i found this engine and im plan on dropping in, could you tell me what engine this bike is out of so if can find out if I need new jets for the carb,they look the same?

NEW ENGINE
gs40x-115524

ENGINE IN BIKE
k501-103580

They are all the same engine but your K501 is a better newer generation.

What happened to this one? gs40-115524

Its out of an 1980-82 gs400x which is a 4 valve per cylinder engine like yours.

The one in the bike is the new generation and the other one is the old gen.

[moose200]

yes its the 8 valve, both are. the gs40-115524 is a slitly used engine that I found in the back of our shop, no idea what happened to the frame, how is it better then the other one thats in the bike?

[Mekanix]

Its not, the k501 number is an updated version of the gs40x engine. Take a look at the exhaust rockers and cams.

They have updated rockers that do not wear the cam like the gs40x

The head on the earlier models have cracking issues between the spark plug and exhaust valve seats. The later models have that issue resolved.

The valve cover has more bolts to hold it down to prevent leaking. The clutch pushrod was changed to a two piece so it wouldn't wear the seal out.

The transmission has a better designed bushing system for the gears.

There's lots of little things like that.

The updated engine has all the parts to make the other engine better though, because all the parts are interchangeable.