I'm almost stumped and I thought I would get the opinion of the before I waste too much more time.

The last time I rode the NSR, a few months ago, I noticed it was not idling as smooth as it had been, but it seem to run OK in the mid range.

I think I have a problem with the front cylinder. It smokes more than the top cylinder and when I put my hand over the exhaust or intake the motor does not die, like it does on the top cylinder. It also seem the front cylinder is running colder than the other. I cleaned checked the plugs and the front looks leaner than the top. I took the carbs apart but maybe I missed something. The vacuum meter is also reading allot more vacuum on the front cyclinder and I can't tune it out. I also checked with a timing light to make sure I was getting spark.

Any Keep in mind this pretty much happened instantly.

Anybody have any clues for me to check. I'm off to check compression and the reed valves.

TIA
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james
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I have exactly 100 psi on both clyinders.
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james
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Not that I think this is the problem, but I did notice something weird.

I bought the HRC reed blocks and stuffers from Tyga. It appears that one is actually 2-3 mm taller than the other. Also, the kit came with two different types of stuffers. One has pointed ends, and the other is blunt and looks like the stock stuffers. The stuffer with the pointed ends will only fit in the shorter reed block (which is the same size as stock). The blunt stiffer fits best in the longer reed block. Is this totally weird and does it matter which reed block goes in which side?
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
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RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

I had an idling problem the same as this on both of my bikes. After cleaning the carbs I balanced them by eye with the spring loaded screw in the centre of the throttle slide shaft. After starting the bike it wasn`t running on one cylinder on idle. I then adjusted the slide balance screw whilst the engine was running, until I got an even idle from both cylinders. You`ll find you have to back off the idle adjuster as you get the non-running side firing. You should be able to achive an even idle this way.

Put the original stuffers and reeds back in and try the motor?

Chester362 wrote:I had an idling problem the same as this on both of my bikes. After cleaning the carbs I balanced them by eye with the spring loaded screw in the centre of the throttle slide shaft. After starting the bike it wasn`t running on one cylinder on idle. I then adjusted the slide balance screw whilst the engine was running, until I got an even idle from both cylinders. You`ll find you have to back off the idle adjuster as you get the non-running side firing. You should be able to achive an even idle this way.

I tried the balance screw and still could not even get the balance close.
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

bushman wrote:Put the original stuffers and reeds back in and try the motor?

It was running fine on these reeds, and there does not appear to be anything wrong with them, but I may give it a try.
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Check the slow jet hasn't been blocked by something.
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Andy.
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Andy wrote:Check the slow jet hasn't been blocked by something.

That's sort of what I was thinking and I will check them again. I also checked the PJs to make sure they were still blocked.

I'm also checking the AJs.

Keep in mind both cylinders are pulling equal vacuum in the mid range.

Andy, what is your take on my reed valves?
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
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RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Well, I put it back together again. Its pulling an equal vacuum on both cylinders, and seems to be running about the same on both cylinders, but it just does not seem to be a smooth as it once was. It barely wants to idle.
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

Because I felt it was running rough I have continued to play with it. Turns out that now the upper cylinder seems weak, but not as bad as the front cylinder was. I don't know what I could have possibly done, but I seem to have moved the problem. All other indications are normal.
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm