Suzuki 2 Strokes

Getting my 76 Gt550 back on the road after ten years. Replacing the fork seals and fork oil.
What wt. fork oil should I try? Rider only 200lbs.
Thanks!
Paul

personal choice really, but i'm only light and i use atf in my forks
cheers, dd.

I would think a max of 10w would be sufficient. Its down to personal choice and riding style. If you ride two-up or fully loaded frequently then maybe up to 15w. But at your weight, and predominantly single/unloaded riding, then 10w is probably a good level in my opinion. However, there are one or two suspension gurus on here that know more than me and may say different.

err, thought i'd already said that? atf [or automatic transmission fluid] is 10w and i've used it for years and years and years
cheers, dd.
p.s. did i mention about using atf or it being a personal choice?

Yes 10W should be fine more important is the air gap. that is the distance from the top of the fork tube to the oil level. I would measure with the fork fully compressed, Springs removed and stat with 130mm. If you are bottoming out the forks you can reduce the air gap to 110mm but I would not suggest going much below 95mm air gap

Cheers

Eamonn

Oil is always a big debate with many different opinions. The manual says 10w/30 with 230cc to 240cc in each leg.i use personally modern fork suspension oil. More oil the harder the ride to soften the ride less oil.

dollydog wrote:err, thought i'd already said that? atf [or automatic transmission fluid] is 10w and i've used it for years and years and years
cheers, dd.
p.s. did i mention about using atf or it being a personal choice?

Lol. Sorry DD I didn't know atf was 10w. Does that apply to all atf or only dexron 1?
As for it being personal choice. I meant to say that I agree with your previous post. I should have italicised the word "is". I really should re-read my posts before clicking on the submit button!

me two, especialllly my speling gettin worse
afaik, all atf is 10w, but don't quote me on it. i'm only 12 stone and atf works fine with the factory spec for the fork oil amount.
cheers, dd.

'Back in the day' Eddie Crooks (of Crooks Suzuki) advised me to use the same oil as what was in the gearbox. At the time that was Duckhams 20w50. He was talking about his production racer 550J and I was 21, so that's what it got. The bike also had the 'Frank Whiteway' treatment of 'cleaned up' ports, skimmed head and some other stuff. Oh it was quick.
I have similar with the 550A that I currently run, and there's 20w50 mineral oil in that's forks too. A bit thicker so that if the seals are tired, they don't leak either, and I'm now 14 stone rather than the 9 stone I was back in 1972! So a bit of extra damping comes in handy..........
Depends on the model as to how much oil's in. 235ml in J/K, 160ml in later models. Can't remember if it changed at K/L or L/M, but if the forks are too hard, let some oil out.

THIS - https://www.oldjapanesebikes.com//mraxl ... /index.php" onclick="window.open(this.href);return false; - is a good read.

Opinions on oils are like butts - everyone has one and they are all a little different.

Back in the day, forks were nowhere near as sophisticated as modern stacked shims. Orifices were much larger and they needed thicker oils than modern bikes.

With old forks I usually start at 30wt and if the damping is too slow I start to go down on oil weight (grade) but usually there is still not enough damping compared to modern forks.

Oil level makes a noticeable difference to springing but not to damping.

Fortunately old forks don't take a whole lot of oil, so you can try one grade and test it and if that doesn't work get some thinner or thicker fork oil and re-test.

dollydog wrote:me two, especialllly my speling gettin worse
afaik, all atf is 10w, but don't quote me on it. i'm only 12 stone and atf works fine with the factory spec for the fork oil amount.
cheers, dd.

Thanks for that info. I had heard that atf was ok for fork oil due to its anti-foaming properties and have even used it once or twice many moons ago, but I never knew it was 10w.