Why install jet kit?

[shredex]

I'm doing my Senior project on installing a stage 1 jet kit.
Can anyone give me any links to sites that have information on jet kits and what they do?
Wikipedia does not count as a real source.
I need to prove that a jet kit improves performance on your motorcycle, so links to help me prove this point would really help.

thank you.

[1BadFZR600]

I dont know of any site except http://www.dynojet.com & www. factorypro.com ,maybe they have a chart..But a jet kit deffinatley increases the engines hp and tq. From the factory they set the bike at an average to run good at sealevel or 5k ft. When you jet your bike you slowly increase the jet size til it runs great. Immediatly when you install a slip-on exhaust your engine is running leaner, and when you install K&N Pods they allow more air less (vaccum) pull..So you have to increase jet size to compensate...A stock air filter will pull more fuel from a 118 jet than K&N pods will...maybe you are following me....On my bike ive got 140 mains float at 22.5, stock needles, K&N Pods, Supertrapp exhaust with 16 dics..im flowing alot of air through my engine.....

[shredex]

I dont know of any site except http://www.dynojet.com maybe they have a chart..But a jet kit deffinatley increases the engines hp and tq. From the factory they set the bike at an average to run good at sealevel or 5k ft. When you jet your bike you slowly increase the jet size til it runs great. Immediatly when you install a slip-on exhaust your engine is running leaner, and when you install K&N Pods they allow more air less (vaccum) pull..So you have to increase jet size to compensate...A stock air filter will pull more fuel from a 118 jet than K&N pods will...maybe you are following me....On my bike ive got 140 mains float at 22.5, stock needles, K&N Pods, Supertrapp exhaust with 16 dics..im flowing alot of air through my engine.....

I tried them but they had pretty much no info on the kits.
I found info on them at Two Brothers website.

thanks for the info though! it really helps

[1BadFZR600]

What are you really looking for? Documented paperwork where jetting a carb really does actually increase hp and tq? A dyno sheet? Before and after?

[haunter]

factorypro.com

[Speed Demon]

to start with, the original factory installed jets are installed to ensure that the bike will run thru a large (acceptable) range of air densities or altitudes with the stock airbox and exhaust. When you change altitude the amount of available oxygen changes also(oxygen is the component that allows the fuel to burn) lower altitude=greater density=more oxygen higher altitude=less density=less oxygen. So when you get a bike you can dial in the air fuel mixture it to give your bike the best mixture for the altitude you are running at. It is best done at a shop where they can dyno the bike to give you the best performance. They usually will change out jets with no charge to you and set it perfectly to give you the optimum settings, where as if you do it yourself you have a lot of trial and error and you may need to purchase various jets (in sets) to get it to run its best (and that can be expensive at about $4-7 each).

If you do anything to change the flow of air thru your engine, then you change the fuel mixture unless you compensate. These include changing the exhaust and or the airbox to pods or both. Doing any of these will lean out your air fuel mixture and it will run hotter. This can cause you to burn your valves and melt pistons. So you need to compensate by increasing the jet size to allow more fuel in to richen the mixture and cool down the combustion process.

there are 3 stages. Stage 1: is just to optimize your stock configuration. Stage 2: use when adding an aftermarket exhaust and Stage 3: when using an aftermarket exhaust and pods

somtimes instead of using a larger jet you actually need a smaller one, and also sometimes just switching to a K&N filter in your stock airbox is enough to change the need for rejetting

if you want actual numbers, that will depend on the dyno, the bike, the altitude, and the way you ride it. I wouldn't worry to much about the numbers if I were you. if it is stock you would be fine without unless you want to optomize performance. But, it you add an exhaust or new air filter or pods, it will cost you a lot more when you can't start it anymore because you burnt the intake valves or you have melted the piston. (sometimes a slip-on will not change the airflow enough to necessitate rejetting. But I had a new 96 YZF600 with a slip-on from the dealership they said it was fine and it became hard to start after about 6k and had to replace the intake valves. Luckily they admitted that they did not rejet it and covered it under warranty. )

[Speed Demon]

where are you located in Florida? I see that you have a Yoshi exhaust. you will need a stage 2 kit. If you are near Orlando I know the best place around there you can take your bike to get the work done.

[shredex]

where are you located in Florida? I see that you have a Yoshi exhaust. you will need a stage 2 kit. If you are near Orlando I know the best place around there you can take your bike to get the work done.

i live in between tampa bay and new port richey. I have a place called R & B motorcycles that I can bring my bike to.
So im going to need a stage 2 because of my exaust? on the dynojet site, they only sell stage 1 & 3 for my bike. or is it all included in it?
thanks for the info!

[1BadFZR600]

Its all in the kit...the biggest jet that is in there is a 130 main...If you have stock air box you wont have to go that big.......I believe stock airbox and slip-on exhaust is 118 main? Maybe that helped....

[shredex]

Im thinking about getting the K&N individual air filters and a Flo-commander kit also.
I do not know how much the flo-commander kit is, but the air filters are about $80.
The jet kit it $125
Im going to be spending almost like $300 bucks on my senior project.
So I might need the 130.
or ill just go with the stage 2.

And I need to know, do bike mechanics make alot of money? like how much a year. I would like to go into this trade after high school.

[yamaha_george]

I'm doing my Senior project on installing a stage 1 jet kit.
Can anyone give me any links to sites that have information on jet kits and what they do?
Wikipedia does not count as a real source.
I need to prove that a jet kit improves performance on your motorcycle, so links to help me prove this point would really help.

thank you.

Shredex,
Look for papers by Blair from Dublin UNi on air flow thro engines, see if you can source books by Gordon Jennings, John Robinson (he of late Performance bkles mag) also John Bradley's race bike design books. Web wise there is Mc Dizzy archive on engine tuning.

There is also the engine list at micapeak.com who have some REAL gear Heads on it.

There was also work coming out of NASA labs as well at one point
HTH
Geo.

PS if you want ISBN numbers let me know I have all the books I mentioned and some others besides :-} Nerd

[shredex]

Shredex,
Look for papers by Blair from Dublin UNi on air flow thro engines, see if you can source books by Gordon Jennings, John Robinson (he of late Performance bkles mag) also John Bradley's race bike design books. Web wise there is Mc Dizzy archive on engine tuning.

There is also the engine list at micapeak.com who have some REAL gear Heads on it.

There was also work coming out of NASA labs as well at one point
HTH
Geo.

PS if you want ISBN numbers let me know I have all the books I mentioned and some others besides :-} Nerd

That would be great!
yea, send me all the ISBN numbers for the books, Ill have my library order them for me .
just put the name of the book next to the number if you can.
thanks!

[shredex]

Its all in the kit...the biggest jet that is in there is a 130 main...If you have stock air box you wont have to go that big.......I believe stock airbox and slip-on exhaust is 118 main? Maybe that helped....

well, my bike gets up to 210 degress when im riding for awhile and just sitting at a stop light in the heat.
when Im riding it though around 50 mph, it cools down to about 175.
I dont know if this is to hot or not. I would like to get K&N individual air filters

[yamaha_george]

Shredex,
Look for papers by Blair from Dublin UNi on air flow thro engines, see if you can source books by Gordon Jennings, John Robinson (he of late Performance bkles mag) also John Bradley's race bike design books. Web wise there is Mc Dizzy archive on engine tuning.

There is also the engine list at micapeak.com who have some REAL gear Heads on it.

There was also work coming out of NASA labs as well at one point
HTH
Geo.

PS if you want ISBN numbers let me know I have all the books I mentioned and some others besides :-} Nerd

That would be great!
yea, send me all the ISBN numbers for the books, Ill have my library order them for me .
just put the name of the book next to the number if you can.
thanks!

S,
Ok here goes, bear in mind that what is two stroke is the same theory as 4 stroke but simply stated:-

Gordon jennings "2-stroke tuners hand book" isbn 0-912656-41-7

A.Graham.Bell "2 strokeperformance tuning" isbn 0 85429 329 9 OR 2nd edition 1 85960 619 9

k g draper "2 stroke engine its design &tuning"

John Robinson "motor cycle tuning 2 stroke " isbn 0 434 91741-9

John Robinson "motor cycle tuning 4 stroke " isbn

Roy Bacon "2 stroke tuning "isbn 0 8518 4039 6

Kevin Cameron "sportsbike Performance handbook" isbn 0 7603 0229-4

John Bradley "the racing motorcycle a Technical guide for constructors" VOL 1 isbn 0 9512929 2 7

John Bradley "the racing motorcycle a Technical guide for constructors" VOL 2 isbn 0 9512929 3 5 (note this is more chassis fabrication etc than engine related but a damned good read for a budding modder or bike builder)


Each of these books has a chapter or more on engine basics with regard to thro put of fuel some the whole book is very specific about the interelationship of all the bits from airbox to exhaust being the some of all the parts .

John Robinsons 4 stroke book should be your first priority and dig for references to Prof. Blaires work on engine development from Dublin Uni.

also take a look at McDizzy's web site which is wealth of tech knowledge & software for engine tuning (I wish I had found it earlier then I would not have written my own software for tuning DOH )

[shredex]

well, I am unable to find any John Robinson books. I cant find them on amazon or anything.
do you have a second choice?

I found a book called "101 Sportbike Performance Projects" but im not sure if it will have anything about jetting in it.


BTW, thanks for all the help.