Hey all,
i know no one likes to give out their jetting secrets, but here goes
mc21 stock airbox, tyga dual side pipes, carbon reeds, oil injected

This is gonna be a street bike and i want it reliable
not supertuned so that if the temperature is off that day i am gonna seize

i live in southern maine so im thinking ill have 2 differnt setups that i ride with.. spring/fall 60-70's(colder setting) and then change to a warmer jetting for the midsummer 70-high80's- then back to the previous for fall

ive looked at the tips on jettin here etc.. ive jetted two stroke dirtbikes before, but this will be my first adventure into the carbs of an NSR

Can anyone give me an idea of a ball park jetting, or a set it and forget it setup that is based on the temperature / general elevations of my area. i dont care if im down one horsepower to what my ultimate could be
as long as it runs good and is reliable.

better to just buy the few jets i need? or get the HRC jet kit... from what ive read that only seems good if you are premixing...

any help or part numbers would be appreciated.

Email me at corn_pop45@yahoo.com if you dont wanna share your jetting specs openly..

Thanks
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Koren
2 Strokes and I'm Off

When I had my street NSR with TYGA pipes, and stock intake I ran stock jets.

It wasn't until I switched to the jHa AirForce Air box lid when I changed my jetting. Don't remember what I set it at then, and the bike is gone now.
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Charles Gallant

I think you'll find the HRC kit way too big for your setup. The smallest jet is a 180 (in my kit anyway) and I doubt you'll need any more than 160. More like a 150 I'd say.

Best thing is a dyno setup if you can afford it.
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Hey, I have the same set-up but also Tyga mod airbox lid, Dayton filter, HRC jet kit, using B kneedle, 150 mains, and everything else stock settings. Can't remember were the clips are set, but that's easy to adjust. And you can see I'm in your area. Started out with stock jetting and pipes, and it ran fine. I think if you haven't messed with the air box your close with stock, probably a good idea to see what you have for jetting anyway seeing as you are not the original owner. Have you derestricted the bike ?
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yeah its de restricted
i dont mind running stock jets, if it is as long as it wont blow my motor
i just dont wanna start it up and have it sieze right off due to stock jetting

sounds like you guys think id be okay with stock
and then adjust it a bit more if i want?
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Koren
2 Strokes and I'm Off

Run it up a couple of sizes to be safe, I'd say. You can always go back down, but if you start too small, then you may not get the chance to experiment!
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Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

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And that my friends is hard won advice...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

okay so this weekend if i have a chance i will pull the carbs and see what i got in there. sounds like 150 might be a good place to be?

where can i order single jets for NSR's in the USA.
i have seen places to get the whole hrc type kits
but i should just be able to order a few mains from 145-165 or so i would think.

Can honda get these for me with just the part numbers or is this another only available in the UK or Japan deals?

Thanks! for the help
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Koren
2 Strokes and I'm Off

you could try your local motorcross shop for the jetts.

NSR.wayne is right. Most decent shops will have a supply of jets. No need for an HRC kit if you're going to keep the injection. Just get a decent range of jet sizes so you'll have them handy.

I was able to order individual Keihin jets from my local honda shop - in fact, they had some in stock. My suggestion would be to bring in the stocker from the bike so they see what type it is. Can also look here for part numbers of individual jets (http://www.sudco.com/keihinjets.html). Cost approx. $3 per.

FWIW, if you are running stock (unmodified) airbox, stock motor and injection, with Tyga pipes, I think 165s will be way rich. My experience with MC21 with that exact set-up (but including M-Max de-restricted) was that 145 was too rich (bogged at 10k). Took it to 2-stroke race expert and he dynoed etc. and came up with 122 mains (!) and slightly richer pilot jets. Bike ran well but I was too nervous about it and in the end put 128s (stockers) back. Still runs well, and I may go up to 132s when I have a chance, though it made it through the cold (for San Diego) season without issue. Just some data for reference. hth.
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-Jim
'93 MC21