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Discussion Starter · #1 ·
Ok, i hope this isnt too repetative, but i did search, and found nothing of interest really.

My bike has a K/N and Yosh bolt-on pipe. it is running lean in the low and mid range, especially when its really cold out, The idle goes slowly down when you let off the gas, etc... im taking these signs from my old nitro RC cars i used to race that we tuned. ANYWAYS.

I want to get the factory pro jet kit(supposedly no drilling, etc) but had a few questions. Should i do it myself or let the dealership do it? I have worked on a lot of cars in the past, but never anything with a carburator, i just dont want to get myself into someting im gonna regret. dealership wants like 250 for the install. I guess i am debating if i want to go through all the hassle, or just put in a stock air filter and forget about it.. i dont really do stunts/wheelies, etc i just like to ride but the extra power and resale value seems it may be worth the cost.

Some Qs i have:
Do you have to pull the carbs off the bike to put in the kit? from my repair manual it looks like the carbs can be played with with the tank and airbox off.

What tools are required to do this... i have a nic ecollection laying around but i like to know in advance before i start a job.

ok, thanks for all your help you guys!

=Scott M
 

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A jet kit is really not worth it on your bike. You may get 2-3 horsepower. I had a problem with the idle returning slowly on a 98 600 and all it needed was the carbs synced. Your low and mid range doesn't have anything to do with your main jets anyway. There are other adjustments in the carbs for those.
 

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Try tuning the mixture screws out about a turn or so. If the carbs have never been touched, you'll need to pull the plugs off of the screws and you'll probably need to remove the carbs to do it.
 

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Discussion Starter · #4 ·
supposedly the bike has had the carbs cleaned and resynced at about 12k miles. has like 16k on it right now.

oh yeah, the bike also stumbles when you get on it hard and it is a little cold outside, as in it sounds like its choking from not enough fuel, then it gives a sudden burst of power. if let at idle bike temp will rise to about 210-215, when riding it stays around 175-185 usually, low gear cruising gets it up to around 190.

i know the HP gain isnt much, im not really concerned about HP because its a bike, it goes fast... obviously LOL... what i really am looking for is a smoother powerband, more punch, just an all around smoother bike to ride.

thanks,

scott
 

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Discussion Starter · #5 ·
one more thing, the bike will "buck" when cruising in 2/3 gear at lower RPMs occasionally if the power is not kept modest. from what i found on sportbikes.net in a nice tutorial:

? NOTE: A rich problem gets worse as the engine heats up.
? If the throttle is lightly "blipped" at idle, and the rpm drops below the set idle speed, then rises up to the set idle speed, the low speed mixture screws are probably set too rich: try 1/2 turn in, to lean the idle mixture.

? NOTE: A lean problem gets better as the engine heats up.
? If the throttle is lightly "blipped" at idle, and the rpm "hangs up" before dropping to the set idle speed, and there are no intake leaks and the idle speed is set at less than 1000 rpm, the mixture screws are probably too lean: try 1/2 turn out, to richen mixture. Be sure there are no intake leaks and the idle speed is set at less than 1000 rpm!


the second sounds like my bike ( as well as my old cbr that had a pipe but no jetting).

>>How easy is it to adjust the mixture screws, and do they only adjust the low range and not the top end? also how many are there, one per carb or two for all 4 intakes, or what.

sorry for all the questions, but all my experience with carbs has come from very expensive .21cc mini race motors that had two adjustments on them - top and low end.

thanks again in advance.!!!
 

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It might just need a new set of plugs. It's worth a try before you spend $250. I had a 2000 600 jetted and dyno'd and I hated it. Ran better at the top end but power was not smooth and low rpm sucked major ass. Could have just been the tuning at the shop I went to but it wasn't worth the money for 2 horsepower. I would definately change the plugs first though if it hasn't had a new set yet.
 

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It might just need a new set of plugs. It's worth a try before you spend $250. I had a 2000 600 jetted and dyno'd and I hated it. Ran better at the top end but power was not smooth and low rpm sucked major ass. Could have just been the tuning at the shop I went to but it wasn't worth the money for 2 horsepower. I would definately change the plugs first though if it hasn't had a new set yet.
Agreed! I have a 98 600 now and I've never rode it when it was stock. It has KN, yosh full race, jetting is from factory pro. It has always been slow and sluggish at low rpms and has a sudden change of heart at around 5000 rpm. If I were you, I wouldn't change the jetting at all. It is not worth it for the problems you'll have for doing it. BTW does anyone have or know the stock size jetting (main,pilot) for 98 600?
 

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It might just need a new set of plugs. It's worth a try before you spend $250. I had a 2000 600 jetted and dyno'd and I hated it. Ran better at the top end but power was not smooth and low rpm sucked major ass. Could have just been the tuning at the shop I went to but it wasn't worth the money for 2 horsepower. I would definately change the plugs first though if it hasn't had a new set yet.
It was definitely the tuning. There's no reason whatsoever that the shop shouldn't have been able to smooth out the power curve, especially having a dyno at their disposal. I'd talk to them about that.

The main jets pretty much only makes a difference at the top end... you can have your cake & eat it too. The main needle, pilot jet & adjustment, slide, and other factors come into play in the low-mid range.

IMO - properly jetting a bike should focus around throttle response and smoothness first, HP second. But there's no reason why a shop with a dyno (assuming the bike doesn't have other mechanical issues) can't deliver both.
 

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Discussion Starter · #9 ·
ok looks like i will just toy around with the carbs to get them running the way i want. 600cc is fast enuf on the top end for me anyways, im not a speed deamon by any means! bike has 2 up in the rear sprocket so that adds some top end anyways.

i will take the suggestion and turn the carbs out a half turn to try to get it running a little richer on the low end. i asusme lefty loosy righty tighty? also, is it best to just turn them out a 1/2 or run them all the way in then back them off all to the same spot +1/2?

if i cant get it i may just take it to the shop to have the carbs redone and synced.

oh yeah one more thing, i tried to get on it today in 1st gear pretty hard from low rpm and the bike like bucked 3 times really hard then it took off, it was a pretty violent bucking, im assuming lean.

thanks in advance!
 

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Ok, i hope this isnt too repetative, but i did search, and found nothing of interest really.

My bike has a K/N and Yosh bolt-on pipe. it is running lean in the low and mid range, especially when its really cold out, The idle goes slowly down when you let off the gas, etc... im taking these signs from my old nitro RC cars i used to race that we tuned. ANYWAYS.

I want to get the factory pro jet kit(supposedly no drilling, etc) but had a few questions. Should i do it myself or let the dealership do it? I have worked on a lot of cars in the past, but never anything with a carburator, i just dont want to get myself into someting im gonna regret. dealership wants like 250 for the install. I guess i am debating if i want to go through all the hassle, or just put in a stock air filter and forget about it.. i dont really do stunts/wheelies, etc i just like to ride but the extra power and resale value seems it may be worth the cost.

Some Qs i have:
Do you have to pull the carbs off the bike to put in the kit? from my repair manual it looks like the carbs can be played with with the tank and airbox off.

What tools are required to do this... i have a nic ecollection laying around but i like to know in advance before i start a job.

ok, thanks for all your help you guys!

=Scott M
]


........... Take it to an experienced carbed gsxr mechanic. It's worth it.
 
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