5k hump

[chris5150]

this is my first bike and i am not to sure what my problem is. i got it a couple of weeks ago.

this site has been very informative but i have not heard of any thing similar. 

it takes a little while for my bike to warm up(3-4min). and it is like i loose power around 5000 rpms but after 5k it is great. the longer i ride the less it can be noticed. after riding for about 20 minutes it can hardly be noticed.

my best guess is that i am not getting enough fuel. it also has a custom muffler on it and does not seem to have much back pressure. it looks like i have the stock air box.

i will post a picture tomorrow to show the muffler. please any ideas would be helpful

also this only happens when it is under load if i rev it is fine.

thanks

p.s. in a couple months i am planning a Vance & Hines super sport full system, Dynojet jet kit and K&N lunch air filter.

[Wrecent_Wryder]

I7

[natedawg120]

I'd bet it has the stock jetting, and with the exhaust mod you're running lean enough to get a "flat spot" there. What year is it?

You'll have to rejet for the V&H and/or lunchbox anyway. Most here would advise against the DynoJet kit, I know I would. Just buy jets.

+1
That is what I would guess as well, esp with the aftermarket can.  Check to jets, if stock rejet, and get a drop in K & N filter, that should straighten things out. 

[Crash-n-Burn]

I usually let my bike warm up for 5-10 mins, it seems to ride much smoother when it's warm.

[dchrist]

my bike takes a good 5 minutes sitting to warm up if the temp is less than 65 degrees. then another 5 or 10 riding before its smooth.

I bet the fuel system upgrade and dyno jet mod will fix your issue

I re jetted without dyno and have been happy. if you're looking for votes I say just buy the jets.

[chris5150]

i rode it over to a mechanic friend of mine and he agreed that is a jet issue.

thanks for the info within 2 months i will have new exhaust, k&n, and a jet kit.

after that i will post some video on youtube and let ever one hear what it sounds like.
for those people who are interesed in do ing the same mods.

[ducati_nolan]

Don't bother with a jet "kit" if you search this site and/or go to the wikipedia for the GS there is a chart telling you about what size jets and shims you'll need for your intake/exhaust setup. It'll save you some money and work just as well. doing the air filter/exhaust/jetting all at once is great and you'll love how the bike responds better.