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SMP 420
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Discussion Starter #1
I have a 1999 R6 that is acting up. When the bike is in Neutral it runs fine no issues and I can rev the bike up to red line with no issues. The problem comes when you go to ride it in first gear I can get it up to about 12K rpms and in second gear I can get up to 10K RPM in all the remaining gears it will not go past 8K rpms.Under hard acceleration it is like hitting a brick wall and I can keep the throttle wide open and it will just stutter along at those rpms and cruise down the road but won't produce anymore power. I can back off the throttle and ease it back up and sometimes it will climb to a higher rpm but not much higher. Has anyone else dealt with something similar?


Here is what I have tried so far with no luck.

Changed fuel filter, fuel pump, oil and spark plugs. I have cleaned the air filter, cleaned the carbs, jetted the carbs, I've tested the charging system with a voltmeter, I've tried running the bike with the headlights disconnected, I have looked for pinched air or fuel lines. I have checked the headers by spraying with water and all cylinders are firing, I have checked the coils with voltmeter and they tested alright but I had an extra set of coils in another running bike so I swapped them out for shits and giggles. I'm sure I am forgetting something but even after all of this there has been no significant or noticeable changes! :mad::bash I'm running out of ideas and I really want to get this bike running!
 

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Parts Pimp
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26,473 Posts
The slides in the carbs are probably not lifting. I can't imagine the jetting being so off that it stops at 8k. But from 8k to redline the slides are supposed to be up fully and allows you to keep ripping.

You should lift off the black caps on the carbs and inspect the diaphram that is attached to the slides. If any kind of cleaner or gas has gotten onto them, they are probably destroyed. In the corner of each one where it sits under the cap is a small brass pin. that has an o ring around it too I believe. This is what creates the vacuum to lift them.

Get back inside the carbs and target your search at these slides and the diaphragms.
 

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SMP 420
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Discussion Starter #3
Alright I will take another look at the carbs tomorrow. Do you think adjusting the needle heights could help fix the issue?
 

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Parts Pimp
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Alright I will take another look at the carbs tomorrow. Do you think adjusting the needle heights could help fix the issue?

If everything looks good with the slides then yea I would adjust the needle height for sure. The issue is slide related. Whether they just aren't lifting at all or if the needles are so off that when they do lift the bike bigs or goes super lean.
 

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SMP 420
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Discussion Starter #5
Alright after checking the slides I found that the 3rd one from the left is not opening up all the way it is only opening up about 3/4 of the way. I am going to fix that and test it again and if it is still acting up adjust the needle height. I'll let you know how it goes.

Thanks
 

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Parts Pimp
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Alright after checking the slides I found that the 3rd one from the left is not opening up all the way it is only opening up about 3/4 of the way. I am going to fix that and test it again and if it is still acting up adjust the needle height. I'll let you know how it goes.

Thanks
:cheers
 

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SMP 420
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Discussion Starter #7
Alright I fixed the slides they are all working properly and adjusted the needles from the second slot to the second to last slot and the bike is still doing the same thing. Plus all the needles were already shimmed. So back to square one on that. I did notice that the idle was a little rough after adjusting it.
 

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Maybe some coil make trouble?
Is the engine don't reving up - without any special "blipping" noise? It sounds like leaning out?
Or do you hear some bangs from the exhaust? (= ignition trouble)
 

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Have a very similar problem. Please has anyone solved this issue?
I been told that because mine is a grey import that it set like that for the specific country it was built for. Anyone heard of this before?
 

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How would one check that?
Carbs have been cleaned, serviced, and balanced.
Airbox is k&n filter. Cleaned and lubed.
New plugs. Coils checked.
Idles smooth, pulls through revs nicely, but not going past 10k rpms.
Was told r6 such a super good bike. Starting to think I bought a dud.
Every manual i have found shows a different wiring diagram for coil wires. If i try any of those configurations bike wont even fire up.
 

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I don't have a specific idea as such, just to make sure the ram air ducting is clear from the nose of the bike back thru into the airbox. Sounds a lot like a fueling or air problem, but my 99 has not acted up in this way.
 

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Revs freely past 10k with no engine load.

Won't rev past 10k with engine load.

Sounds like it's not able to generate enough power under load.

Potential causes for low power output are many. Air is pretty much guaranteed. If it's not missing and the spark plugs are properly gapped, good on appearances (not fouled for instance), then that leaves timing and fuel to check.
 
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