What Model do I have??

[dubepj]

My bike is a 1984 Model SK. Canadian model.
I've seem reference to a 256, 306,447, or a 533.
Is that the engine model??
Which one do I have??
Thanks.

 

[Jim]

447 far as I know

 

[dubepj]

Thanks Jim

 

[5twins]

Yes, those numbers refer to the engine type. The 256 and 306 were the very early ones, up to around '73 I think. Then they changed to the 447 engine which is most likely what you have. The 533 was a long rod version sold only in Europe I think, so I doubt yours is one of those. Other than that, it appears you have a mildly modded Special on your hands. The U.S. didn't get an '84 model, '83 was our last. Canada did get an '84 though, but it's not any different really than the '83. I think Yamaha was just using up their stock of parts to make a limited model run for some markets. Your Canadian model did get the mag wheels with a drum rear, which is nice. In the U.S., we only got mags up to '81, a drum rear mag only on the '81 model, then spoke wheels after that.

 

[BowlingSS]

I wished my 81 did not have a drum rear.

 

[BowlingSS]

What is the difference between a 447 and a 533? Just wondering.

 

[5twins]

I prefer the drum, it's stone ax simple, and no worrying about a MC leaking.

The 533 has longer rods and different pistons. As far as I know, that's the only difference, but I could be wrong, lol.

 

[RustiePyles]

I prefer the drum, it's stone ax simple, and no worrying about a MC leaking.

The 533 has longer rods and different pistons. As far as I know, that's the only difference, but I could be wrong, lol.

I was always under the impression that 533’s had a different cam profile as well but couldn’t say for sure.

 

[5twins]

That could be true.

 

[BowlingSS]

So the bore is smaller with a longer stroke. Is the cc any different? Does it have more HP or torque?

 

[Jim]

Bore and stroke are the same as all other versions. The rod is slightly longer... meaning the wrist pin sits higher up in the piston.

Remember, stroke is determined by the throw of the crank. If the crank has a 3" throw, it doesn't matter if the con rod is 3 feet long... the piston will still only rise and fall by the 3" throw (stroke) of the crank.

 

[dubepj]

our Canadian models had the silly lights that came on after bike was running. Our laws for daytime running lights came into force before your US laws did. More wiring and relays to worry about. Mine works so leave it alone if it ain't broke.

 

[5twins]

Well, you can do that, but there's a bunch of 40 year old relays and extra wiring just waiting to go tits up, lol. On my '83, I headed it off at the pass and eliminated all that stuff. It's not too difficult to do. I even went so far as to install the headlight on-off switch from an earlier model ('77) and eliminated the headlight auto-on feature too.

 

[BowlingSS]

What years were the 533 engine? I assume the engine s/n starts with 533.