I have a question about how my bike is performing it's NSR250 SE. My bike is derestricted , aftermarket pipes, stock jetting and stock airbox. When I'm riding it, it never feels peaky always flat when accelerating. I have ridden a friends R model and it feels like the front want to lift when it peaks( which I like ), but nothing like mine, his bike is also modified like mine. Actually I help him derestricted it. What should I be looking at ? It has 15,000 Km on it, new clutch, don't know the condition of the top end except it has around 125 PSI compression when I first got it. I have a new top end and jet kit, have not had time to install.
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Do you have spooge dribbling from the tail pipes? Sounds like the bike is rich to me and needs the jetting reducing a bit...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

I've check the plugs and they come-out nice and coffee brown. I would not say there is excesive spooge, looks normal amount to me !
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Hmm. Gearing differences? Dragging brakes? Worn chain? Duff battery? It's a bit difficult to diagnose from a distance!

If all the above check out ok, then I'm incluined to start swapping stuff like the PGM from your frinds bike to yours...

Oh, just one thing, maybe his bike has been ported by the previous owner? Have you had them both on a dyno to check the power outputs?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

All of what you mention is new or already checked. I guess I need to try another bike. I'm just no sure if this is the right power characteristics for my bike or any other NSR ? I have one other friend with a stock NSR but it's really a Rat, don't know if I would feel safe riding it.
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Hi jeff
What is your bike reving out to, if its under 8000rpm it could be that you rc valves are stuck from carbon build up or your servo motor has died
Regards k

I have check the servo motor and it is working and is set correctly (used the steps here in NSR-WORLD). Would the valves still not move or are they mechanical and must move with the servo ?
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The valves are connected to the servo cables. As long as the cables aren't broken, and the drive shaft not worn square, then the valve is moving with the servo. Pop the right fairing panel off and check...

Have you access to a dyno? If the bike is making more than 60hp then it's running fine and dandy - he's just got a better one!

Just a thought. What year is yours, and what year is his? Reason I ask is that in 1989 the NSR's got restricted, so if his is earlier, it'll be faster (I know you mentioned de-restricting, but it'll help to know the year all the same).
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

His is a 90 R model, mine is a 93 SE model. I'm sure I could get to a dyno, just need the time.
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I installed a crank and a new top-end in an early "R" a couple of years ago. It was on completely stock settings apart from a delimited ignition, and went like a bloody rocket! While apart I marked up the RC Valve back-plates so I could finely tune them on reassembly. Correct setting of the Valves makes a HUGE difference to the engine's performance.

My '92 21SE on the other hand has no real discernible "kick", just a smooth spread of power that gets a little stronger around 9000rpm. My SE is fitted with an HRC jet kit, Ramax filters, HRC head kit, Ethos pipes, and a delimited ignition.

1st gear is noticeably longer than the "R" models' that I mentioned and I think this has a something to do with the feel of the bottom end and low-speed pickup.

If you are still concerned, get a compression test done on both bikes. See if yours reads lower, which would probably indicate the need to fit that new top end!

Andy.
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