[davesisk]

Hey guys...I've ridden my lady friend's GZ-250 to test it out, and I can only get it up to about 52 - 53 mph in 5th gear. Based on what I read here, it should be able to get up to at least 65-70 or so. (I weight about 170 lbs, so I don't think my weight is the issue.) It's a 1999, and seems to run well, start easily, and generally be in pretty good shape. It does seem to burn just a little bit of oil...maybe 1/4 quart every couple hundred miles. I don't know all the details of the stock exhaust, but there is the one stock opening in the cone-shaped muffler and looks like two additional 1/2" or so holes have been drilled into the back plate of the muffler. (I'm a Suzuki S40 owner, and drilling holes in the back of the S40 stock exhaust is a pretty common mod, so I wouldn't be surprised to find a similarly common mod on the GZ250). So, maybe if the exhaust has been drilled, then adjusting the fuel-air mixture to be a bit more rich would give it a bit more power? Just guessing here (the S40's run lean stock, so adjustment the fuel mixture to a bit richer is another common mod for the S40's...again I wouldn't be surprised if the GZ250 wasn't the same given they are both "thumpers".).

That said, any other ideas on what might be limiting it's top speed so much?

TIA,
Dave