puzzled

[almiester3]

Hi all,i have a 2005 gs500 naked. Has drop in k&n filter,stage 2 jet kit,high perfomace coils,pipe, standard gearing. Compression is spot on but i cant get more than 150kph out of it,rider is 84kg. I've checked for restictor washer on carbs etc but nothing. It runs perfect apart from that, i cant think anywhere it could be restricted

[Bluesmudge]

150 kph is ~93 mph. That's around the most I've ever seen out of my fully faired GS. I think I saw 105 on a slight downhill once, which would be 94.5 mph after accounting for spedo error. Are you seeing 150kph on the speedo or GPS verified?

[almiester3]

Thanks, on a gps speedo. Is just ive seen videos of people getting 180-200kph on them

[Bluesmudge]

Are you trying to hit the top speed in 5th or 6th gear? I think with the stock gearing you will see a higher top speed in 5th gear.

Your top speed sounds about right for a stock GS. I would expect a little more with your tuning. Maybe time to get it on a dyno to see what your air/fuel ratio is doing at high rpm.

[almiester3]

the fueling seems bang on by the colour of plugs & no glitches or flat spots. only thing i havent checked is the needle setting on the carbs. Going for it in 5th gear, upto 140kph its really quick sub 6seconds easy

[Bluesmudge]

The color of the plugs doesn't tell you much about how its running at high rpm unless you are cutting the ignition in the middle of a high rpm run. In the days of old it was a good indicator of how the bike was running at idle, but with modern gasoline its very difficult to tell much from the plugs. A rich running bike might look correct or slightly lean with modern gas.

[herennow]

I managed to hit the ton once but that was about the limit, 180 to 200 seems a bit "aspirational"