“The Heretical GSF1200 Released by Contrarian Suzuki” – Inspection, Oil-Cooled Maintenance and More

16 February 2024

Going back to the end of the 20th century. There was that Nostradamus prophecy, you know… the great demon king thing.
Not that, but

the heyday of large-displacement naked bikes.
CB1000SF BIG1, air-cooled 4-cylinder, XJR1200, ZEPHYR1100 – truly big bikes!
While each manufacturer was expressing the modern naked bike aesthetic with twin-shock naked bikes…

“Monoshock/lightweight/short wheelbase” + “affordable” = GSF1200 Suzuki followed suit.
It seemed to sell reasonably well, but… I wonder what the reality was.
Looking back now, there’s always that “got ahead of itself” feeling, you know? It’s a good bike though~

Nickname: Sazae-san

Maybe it’s just me, but doesn’t the meter look like Sazae-san…?
By the way, the meter is a borrowed part from another vehicle, and “GSX1100G” was the base, I think.
Suzuki’s philosophy of “keeping costs down as much as possible” is packed into every corner of this wonderful bike…

Doesn’t look like it? Or does it? If I paint it black, it’s basically Sazae-san…
Not a bad ring to it (*´ω｀*)

I got sidetracked, so now let’s do the oil-cooled maintenance…

Since the bolts were hard to remove, I switched them to ultra-low-profile ones.
Now it’ll be smooth sailing next time! ♪

I’ll replace the shift shaft oil seal.
When you lubricate it and warm it with a heat gun, it really comes out easily.
Lubrication and heating are really important.
Makita Heat Gun 18V HG181DZ is so good that I definitely want to go cordless this year! Please do.

Special tools improve work efficiency the more you have

“A minus driver welded to a boss with a threaded rod and iron round bar” makes a sliding hammer
With this tap-tap-tap~♪ pop! There we go.
Removing at sonic speed… that’s the aesthetic here.

I’ll replace the starter motor O-ring.
And clean up the body too ♪ The starter motor is “body ground”
If you stone the mounting surface with an oil stone, the starter should spin about 0.001% better… (hopefully)

I’ll replace the generator damper.
As expected, it had hardened to a brittle state with plenty of play.
It should be a bit quieter.

I’m polishing the body with a stainless steel brush.
Makita Impact Driver TD173DZ with Shaft-mounted wheel brush stainless steel φ75 is the perfect combo ♪
And again, “going cordless” makes a huge difference in work efficiency.

The generator connector is in good condition. I’ve cleaned up the case side nicely.

The engine damper wear is excessive. The bolt corrosion has also developed nicely.

This might be the first time it’s been replaced.
The more worn it is, the more noticeable the improvement after replacement = it should become smoother.

Do you remove the muffler?

No, we don’t remove it. Especially with oil-cooled exhaust pipes, it’s too scary to work on casually.
“Unlubricated installation with SUS304 bolts left permanently fixed” is pretty scary.
When they break, they’re basically fused together so better not to touch it .

So we’ve been using special tools like this for a while now.
・A wrench bent by heating and hand-bending + a san-ichi tube cover
・Stahlwille half-moon wrench

Using these, we’ve never had an oil-cooled bike where we couldn’t remove the bolts with the exhaust pipe attached so it’s probably highly likely we can remove them.

And extend with an axle shaft “super strong” .
Loosen the bolt like you’re removing it.

This front engine mount is split-type and often installed pretty haphazardly.
In other words… when you want to install an engine slider, “the bolt won’t fit when removed” it shifts that much.
Thinking ahead, it’s good to assemble it carefully so there are no problems later.

Also, there are cases where it’s been forced in and the threads are damaged.
Instead of just a nut, repair it properly with a helicoil or similar.