Hi all,

Took the NSR300 out for a ride today. I noticed when I went to start it that it only starts and runs on the top cylinder to begin with, but after about 30 seconds the bottom cylinder wakes up. Nothing out of the ordinary there from my experience with this bike, but it may be a clue...

Anyway, on hills it was dying in 5th and 6th gear, and you really had to get it in to the powerband to make it go at all. A real misfire about 7,500 RPM. The engine was also making a choofing sound, instead of the smooth sound it usually makes. I decided to pull over and check the spark plug on the front cylinder, as access is easy but it appeared to be burning well. So, I changed the front coil with a spare XR600 coil I carry with me. The bike ran about 50% better, but it was still misfiring about 7,500 RPM and choofing. On the way home I noticed the tacho started to drop out briefly, for about 30 seconds at a time.

Next up I shall probably get new spark plugs and see if that rectifies the problem. From the symptoms I'm describing, does it sound like it could be anything in particular which I should look first at?
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MC21 Honda NSR250. TYGA 300 conversion.

Check Your battery voltage and maybe charging. The NSR is hypersensitive to low battery voltage
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

I checked the battery this morning. It's holding 12.8 V. Checked the voltage with the engine running and it's as high as 14.4 V. Is this too high?
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MC21 Honda NSR250. TYGA 300 conversion.

anonymous.shyster wrote:I checked the battery this morning. It's holding 12.8 V. Checked the voltage with the engine running and it's as high as 14.4 V. Is this too high?

That looks good. 14,4 is on the upper limit but probably not the cause of your problems.
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

Maybe I should have put this in the 250 section as it's got few answers. Ordered some new Denso spark plugs, hopefully this will help. Let me know what you think.
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MC21 Honda NSR250. TYGA 300 conversion.

I received the new Denso plugs in the post and installed them, bike runs a LOT better now. It still has the issue of the tachometer dropping out randomly, though.
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MC21 Honda NSR250. TYGA 300 conversion.

CHECK THe wireing to the cdi where the loom plugs into it or at the plugs where the clocks plug into the loom
could be a bad connedtion