Help identifying GS550 engine year

[Guest]

Hi everyone
I recently bought a GS550 posibly GS550L (never got to see the bike) motor. The only identification is the engineīs serial GS550-205907.
My plan is to rebuild this engine. after some TLC the motor starts the compression seems rather low (90psi Iīve only tested it cold) dropped some oil through the spark plug holes and tested compression again (about 95psi again cold but wet) .... you can tell someone worked on the engine before and didnīt really do a good job nor used new parts so..... after some more testing Iīm going to be ordering gaskets, seals etc..and before doing that I wanted to know what year the motor is to make sure Iīm not spending my money on wrong parts.
Thanks

[JEEPRUSTY]

If you would post a pic it would be easy. Also look for the displacement on the block.
Later gen 550s 83-86 are 572 ccs not sure ehat the first gen are.

[cowboyup3371]

The 81 550T and L are 549ccs per what's on the blocks of my two bikes

[Nessism]

'77-'79 engines have a kick starter, points, small port head (for VM22 carbs), and a 12 pole stator/rotor.

'80+ engines have the large port head (for BS32 CV carbs), electronic ignition w/ignitor (not CDI), and an 18 pole stator/rotor.

Pretty much everything else is same or nearly so.

[JCT]

Thanks to all for the replys
-Nessism ... it is not kickstart so I can discard yrs 77-79
-Jeeprusty and Cowboyup3371 ... The motor has a 549cc stamped somewhere on it I recall seeing that so I can assume itīs under 83 so ... either 80, 81 or 82
and looking around through previewst posts I found this:

(hey, been asking about engine swaps lately. just found an engine from an 1982 GS550
wondering if it will fit in my 1978 GS550C
engine numbers are:GS550-205534 from the 82 engine.
does anyone know a fair deal about parts compatibility? the price isn't too bad. turns freely according to the person selling it. has less than 40,000 miles on it (mine has close to 50, but needs some attention due to time constraints/not being able to afford/do the repairs). i think that the GS series went to 16 vavle in 83/84, not too sure though. if it is an 8 vavle engine, it should bolt in correct? thanks guys.)

I was surpriced this guy has a very similar serial to mine. Since his number is 205534 and is a 82 and my number is 205907 and is still a 549cc engine is it safe to say it is a 1982 engine?

[JEEPRUSTY]

assuming the serial is not some weird coding and an actual ascending mumber I would say yes you have an 82 as it cannot be an 83. Some places and people say they have 8Valve 550s with 549 cc engines You are in the US?
Meh its an 82 prolly.