flat spot

[lroy]

Hi all i have a gsxr 600 srad track bike it has a really bad flat spot between 7000rpm and 9000rpm its fine up to 7000rpm then goes really flat and struggles to get to 9000rpm then it clears and is fine again the exhaust has soot on the end can i think the carbs need setting up does anyone no about this or have any info many thanks

[temeluchus]

Youll need to take a peek at the sparkplugs really as soot on an exhaust silencer is normal.

Try a plug chop-this could be tricky on a full faired bike but can be revealing. Find a quiet bit of road, get it up to 8000rpm and kill the engine. Coast to a stop and check one of the plugs.

Once you get the plugs out and establish if its a rich or lean flatspot, youll then need to get some adjustment done-I dont know which GSXR600 you have, so not sure whether you are carbed or injection. Rich is black and sooty, lean is very light grey or white.

If you are blessed with carbs, you can adjust the needles-higher for richer, lower for leaner. Messing with the mixture screws will make little difference as they are for idle.

If you still have issues and its running rich, one thing to check is the air filter-this can become blocked and cause rich running.

If lean then make sure everything is fitted properly and there are no air leaks in the inlet.
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Some shite cruiser. Now with guns and FREEDOM!

[lonner]

hi


more than likely its just not dyno'd to run the race can you probably have as you nearly always get a flat spot somewhere in the rev range so try it with a standard can or a baffle and see if that cures it.

then you will know its the can as most likely cause as it runs well every where else.

hth

[Ben.]

get you carbs done, its either under/ over fueling because youve changed the air fileter or can or something like that, or the needles worn and needs replaceing.
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follow my racing season
Race bike - R6
Road bike - sv650

[temeluchus]

[Ariel Badger]

At 9000 RPM it will be needle hight, after that you are on main jet.
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[temeluchus]

lol yeah thats what i said!
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Some shite cruiser. Now with guns and FREEDOM!

[lroy]

i have booked it into the garage today they have a dyno so they should sort the problem out they said it sounds like a fuel/carb problem thanks alot for all the info and help

[Blue_SV650S]

When was the last time you chanced the airfilter?

Are all the 'ram air' ducts secure/sealed?
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The purpose of life is to fight maturity.

[lonner]