dynojets vs bigger main jet

[Buffalo400]

Whats de difference between a dynojet kit and a bigger main jet???? There are 100 box between us... and if a bigger main jet bring more gas, a dynojet bring also more gas.... If a bike run richer with a big main jet, there are no advantage to buy a dynojets???
p.s. I have a k&N filter

[Texan32]

The concept behind the dynojet is good for those who ride/race in weather conditions that change on a day to day basis. The dynojet is like having an adjustable main jet. You turn the screw one way= more gas, turn the screw the other way= less gas.

2 stroke motors can be tempermental to weather conditions. 4 Strokes however are like mules! The can handle different climates MUCH better.

The question is this. Do YOU ride live in an area that the temp changes 30+ degrees (mainly for 2 strokes) from day to day? Does the humidity change +/- 50% on a daily basis? Do you have a gas sniffer to tell you the mixture ratio you are running at any given time?

For me...NOT WORTH IT. I have had my jets set for over a year and a half. I have riden in -10 degrees all the way up to 100 degrees. In the winter, i just put the lid back on the airbox. I'm not a pro. I don't have a gas analizer. I don't know if i am running "perfect" jetting.I can tell you this. I have never had a bad spark plug reading, and never had a problem with the butt-o-meter. 100 bucks for a dynojet or 5 bucks for for a jet and 10 minutes of time IF you need to change it.

[northeast400]

no he means dynojets not dial-a-jet

[Texan32]

OHHHH...yeah, i guess i should have read what he actually wrote and not what i thought i saw:rolleyes:

[toby400ex]

Dynojets just use a different number system to than the stock keihen jets. They are a different shape also, no big diff, the stock style jets work just as good, its just the kit that dynojet has that makes some people buy it.

[White_Knuckles]

Dynojets average 1 size larger than Keihin so.. you're right, jetting with any will work as long as you know the size increments. Dyno claims to have better flow charactoristics than Keihin. They have more of a taper to the jet bore and also match their jet needle taper for "optimised flow". I just use Keihin jets and buy 2 or 3 step sizes at a time to dial it in. Some guys swear the Dyno's are great I just don't want to pay $50 for several in the kit I'll never use.

I believe the engineers at Keihin would switch to a similar design bore if there was such an improvment to be had. The Dyno's look very close to Mikunis jet design so it's really nothing new.

Dynojet and K&N jet kits are both made by Dynojet. Dyno also recommends K&N filters, this is a marketing partnetship. The kits including filters and jets are way over priced ($100+) I did a pipe (slip-on Pro Circuit), a UNI filter, UNI airbox pop-in filters and jets for under $250. Results - very noticable improvement cheap. :D