GS450 Engine model Identification

[koolaid_kid]

IDK if you can track by the engine number. I do know that they were never the same number as the frame number. And if you have rectangular end caps it is the 8 valve engine, round is the 4 valve engine.
And I have no source of production numbers. I do know at the time the US was only interested in larger displacement bikes, especially since 4 strokes at the time made significantly less power than equal displacement 2 strokes and were a lot heavier.

[Mekanix]

LOL. They made an 8 valve 450, but it was never sold in the U.S.

Oh really ? Do Tell.

Regardless of what you think you have you can call it a 1980 450 and be 99% right for all parts you get. However there are advantages to newer year parts. So check for differences when you need to get them and compare then.

[koolaid_kid]

Oh really ? Do Tell.

Regardless of what you think you have you can call it a 1980 450 and 99% right for all parts you get. However there are advantages to new parts. So check for parts when you need them and compare then

Showoff.
Get that thing running, doggone it.

[Blacky]

LOL

Thanks for all the help guys!!! i'll get on it... will post more pics as i progress.

I have moulded my own Cafe' style fiber glass seat and have chopped and hopped the frame tail as well, so its coming along...

[Mekanix]

getting there. Learning engineering from scratch

While your looking at the engine take a look at the carbs to see what you have for jets . I wonder if it was properly jetted with those pod's.
Also those look like emgo's. (cheap and sometimes problematic) A good set will help when your tuning it later on.

What you are you planning to do with the exhaust pipes? I see they are just cut off.

You could use the engine number to see what range of years you fall in by using I think was the Haynes manual. In the back it has a few upgrades that later years had. So it says from engine model gs45x$$$$$$ to gs45x%%%%%% you will have the upgrade and all before that you will not.
It could help narrow down the years.


One upgrade that is universal to the base is a two piece pushrod for the clutch. Before 83 it was all one piece and eventually wore the seal out.

The later two piece let the smaller piece that went through the seal, stay still while the engine rotated. That stoped the seal wear.

There are other things like gear bearings that got updates as well.

I think one way to be sure is to look at your valve cover and see what year yours looks like. I think some have bolts in different places. Sort of like they were trying to put the bolts in different places to stop leaks and that created a different gasket.


Pics are good


Also while the engine is in the frame can you get the valve cover off ? You will have to change valve shim's eventually.

[Blacky]

Hey Mekanix,

Again thanks for the guidance, its really appreciated!

I'll check the jetting on the carbs as soon as i tackle the motor, i first want to get the frame sorted, i got the last two engine mounts in position last night so now i can get all the adjusted mounts welded in place!

What pod filters you suggest, i was thinking K&N maybe?

I was thinking of going for stainless tubes and a set of British styled dual trumpet exuast pipes i.e. Truimph Thruxton.

I'll check on the removal of the valve cover... that never crossed my mind...

Have you done any welding on a bike frame, if so what method or type do you suggest, i wanted to try-out Oxy-acetalene for the mounts and other additional brackets but most people i have spoken to recon MIG is the way to go...?

[Mekanix]

Mig. Is much easyer and quicker i find.
K&N RC1822 oval style filters. (Google them)

K&N

[pete]

Just to add to what Mekanix said... sometime between the 81 and 82 model years they went from 12 bolts on the valve cover to 15 bolts. If you have a 15 bolt valve cover, good chance it's an '82 model.

They also changed the clutch pushrod seal and seal retainer somewhere around that time as well. Earlier ones have a seal with a flange and the retainer doesn't cover the whole seal. The later ones have a non-flange seal and the retainer covers the seal completely.

They also changed from a one piece clutch pushrod to a two piece pushrod, so again if you can slide the clutch pushrod out from the left and it's only short, you have the later two piece version, also indicating it's most likely a late '81 or '82 model.

What's the engine number? Mine's an '82 so if yours is higher or lower it may give some sort of indication for a guesstimate...

If you look on the parts fiche at www.alphasports.com at the valve cover section, you will see the engine number at which they changed from the 12 bolt to 15 bolt pattern, so this will help you identify it also.

Aside from those minor details, everything from 80 - 82 is pretty much identical.

One thing's for sure if the cc's listed on the head are "448" then it will be no earlier than '80

Edit: seems I only read the first page when replying... I missed everything else so apologies for the duplicate info...

[Mekanix]

Nope, all new and valid info Pete.

[pete]

Glad to hear it

It's amazing how much you miss when you haven't been on in a while...