nitrous on a motorcycle

[1212FBGS]

why are you trying to screw with your jets? let me ask ya this..... why do ya think an 80hp shot for a 4 cylinder 4 nozzle kit is the smallest kit most of the NOS manufacturers sell?.... Ya think they have had, or know of problems with running a smaller jet? like freezing or plugging? smallest flare jet ive seen is .010 and funnel jet at .008.... NOS is tricky enough..... just put in the 18hp shot and run it....
kent

[Speed Limit 1000]

Kent Ya think you were clear enough  

[JoshH]

Racer X - just so you know NX makes jets .009, .010, .012, .014, .015, .016 - they use the tiny one's in RC cars

[wobblywalrus]

Nitrous is something I have not used, but I have done other similar goofy stuff.  One thing I learned is to take plug chops during the first runs and to look at the plug with a magnifying glass.  Look for any molten aluminum flecks.  Look down through the plug hole at the piston crown.  The carbon coating should be light tan to nipple brown.  Bare metal or pitting on the crown is an indication that it is time to do something different.     

[1212FBGS]

with nos you don't get a chance to do plug chops and look see how every things gettin along within your motor...... its usually everything is tuned up and fine then  blaaaaaaaa as it melts your piston and head or BANG as it tosses a leg out the cases.....your tune up can be good 1 day and junk the next...... 2 things are for sure with NOS, everyone gets greedy and you will blow something up...
Kent

[racer x]

Thank you all for the responses.

I understand you logic with freezing jets. and getting carried away with unrealistic expectations.Greed dose not play into it though 

  I have very specific goals and expectations.
I am not building a Hyabusa.it is a 3500 dollar started bike with a fragile 249cc engine. 
  I will eventually need to turn my engine 1000 rpm faster than it will turn now using one less tooth on the rear sprocket. Or 750 more RPM with two less teeth out back..not much to ask but a lot to do.
.

[Stainless1]

with nos you don't get a chance to do plug chops and look see how every things gettin along within your motor...... its usually everything is tuned up and fine then  blaaaaaaaa as it melts your piston and head or BANG as it tosses a leg out the cases.....your tune up can be good 1 day and junk the next...... 2 things are for sure with NOS, everyone gets greedy and you will blow something up...
Kent

ABSO-FRIKKIN-LUTELY... ya know that one more step up will make the back-up run fast enough for a record faster than the qualifier....

I don't think you will have problems with the little jets freezing closed, but you need to filter the gas, and put a Murphy switch on it so N20 won't come on unless you have gas pressure. 

If you are lucky the first indication of a problem will not be a big hole.... just a little hole or a burned valve... 

[Seldom Seen Slim]

Another way to put it (what Stainless said) is to try to run a big number on your qualifying run (at Bonneville, that is -- no two-run requirement at Maxton) so you can back it down a tad for your return run.  It's really a bummer to grenade the motor on that second run -- when you ran pretty well on the qualifier.  As usual -- don't bother to ask me how I know.  But -- for the record, see the Photogallery and the section called "Offerings to the Gods of Speed" and you'll see my plugs and a well-ventilated piston.  It took about 8 seconds from when I pushed the button -- 'til I needed some internal work on the motor.

Speaking of that part of the gallery:  Folks, if you've got photos of the parts that you've damaged and are willing to share 'em -- send them along and I'll get them into that section, too.  Not that many folks will be able to learn from your sad situation -- but once in a while we need a good laugh and a reminder that it's not all that uncommon to damage a motor or hurt the tranny (or whatever) when doing this land speed racing thing.

[racer x]

With Maxton you don't have to back up the last run. We race Five times a year. I need to BETTER the last run every time I go .

I dont think anything will freeze in North Carolina in June.

[1 fast evo 2]

I agree with Kent. Stop trying to over think and engineer the kit and the use of it,start with a known setup(the 18hp kit) test it and go race. I'm not a nitrous guru but I used to use it on my talon I used to drag race. As for the tune up I would use your box and pull the timing down a degree or two, jet the n20 so it runs a lot richer than you have been ruining(I don't know na numbers but I would guess somewhere in the high 12 to 1 afr), as good a gas as you can run per the rules, maybe a colder plug(non-projected tip), and last but not least I would start spaying it in 3rd or 4th gear.

All right you motor bike guys it's time to pick apart what I said to see if I'm even close on a bike.

                         Mike Reichen

[racer x]

I agree I should just go for the 18 hp set up . It is a lot but lets see what happens. I will drop the compression with a thicker head gasket.and adjust timing accordingly. I will balance the octane requirements of a low compression motor with the needs of the nitrous.

As for spraying in third gear. I am a little afraid to push nitrous in lower gears.The architecture of the engine is not robust.

How did the talon trans hold up?I fooled with them a while back. Seems like they had some trans problems.

[fredvance]

I'm not a n2o guy but I run high 12s afr. would think maybe mid 11s for n2o?

[1212FBGS]

you don't want to lower the compression for NOS... it will run like a dog turd when your off the button....a dedicated NOS motor is built way different than a gas motor but lowering static and cranking compression is NOT one of the changes
kent

[racer x]

That is good to know. I am at close to 13 to 1 now. M was going to use 12.5 to 1 for nitrous.

[joea]

racer....many ways to skin a cat.....

nothing in stone...all with a grain of salt...

i ran 8.5-1 and was one of the key features of our nitrous
motor...at bonn....for many years...