Suzuki 2 Strokes

Hi all. Recently picked up a 73 Gt250 and whilst I owned one back in the seventies, I don't recall the front forks topping out as this one does when putting it on the centre stand or riding on rough roads under acceleration which results in a hefty clunk!. Forks have been overhauled by the previous owner and have fresh oil ( transmission fluid by the look of it) any thoughts or advice would be much appreciated. Thanks

Check the fork spring sag. Its how much the forks compress going from no weight on the forks to you sitting on the bike & barely using your feet to balance the bike.

I wonder if he reassembled incorrectly. Possibly he omitted a ring or assembled in the wrong order? Springs might have sagged, as already mentioned. Or there could be insufficient oil.
Since it goes bang I would consider the damping being faulty. Check the amount of oil is correct. If that doesn't fix it, strip and check the assembly against a parts diagram to see if he has put it back together incorrectly.

I was thinking along the same lines that it may be a damper issue as the rebound is fairly instant without much control. In terms of fork oil grade, I know may people use atf fluid but I'm unsure what SAE that is compared to conventional 10 or 5W.

I see that Suzuki specified SAE 30w for the forks, I presume using a much lower weight oil as has been used in my bike would result in the poor rebound damping I'm experiencing . Any advise would be welcome.

The GT250 had rebound damping? The GT380 of the same era didn't. That is why so many guys modify their shocks to give them a little.
Dollydog is the resident GT250 expert on here. He might be able to tell you if they had rebound damping or not and how to counteract your problem

Well when I said 'Rebound damping', what I meant was returning from compression!......Think I've found the issue, only 100cc of oil in each leg, think its supposed to be 220!

Tapnell wrote:Well when I said 'Rebound damping', what I meant was returning from compression!......Think I've found the issue, only 100cc of oil in each leg, think its supposed to be 220!

Yes according to Suzuki service manual 220cc is correct. Glad you found the solution!
I knew what you meant by rebound damping. According to this guide http://www.ozebook.com/compendium/suzi/ ... AtHome.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
"Compression damping on the mid-sized Suzukis is fine, but rebound is way too light."
From that I would assume most of the Suzuki bikes of the era were similar. However, that doesn't mean to say they can't be a lot of fun!