View Full Version : Which jets do i buy?
Ghostv2
03-28-2014, 02:25 PM
So i am looking to buy some jets for my 225dx.
Here is a link to the page with all the jets and such. http://www.bikebandit.com/1985-yamaha-tri-moto-225dx-ytm225dxn-carb-kits-parts-accessories-universal/n1137?m=146955
I have a 120 main but i feel a 115 is what i need. So i will need one of those. I am also looking to go up a size with my pilot jet. I have a DG exhaust on it but still have a air box on it and all so which one should i buy? It runs fine now but just will not idle at all. So thats what leading me to believe i need a bigger pilot jet.
Im just not experienced with jetting what so ever so i dont know what to buy and with all the different jets they show i feel lost.
Here is a chart with stock specs, trying to make this as easy for you guys as i can.
http://i281.photobucket.com/albums/kk237/coloredname1/jets_zps22f5feb3.png (http://s281.photobucket.com/user/coloredname1/media/jets_zps22f5feb3.png.html)
Unless someone has these jets they dont use, i will buy them.
Ghostv2
03-29-2014, 12:43 PM
Nobody? I can figure out the size, i just dont know which ones to buy. There is 4 pages of jets and various parts.
ironchop
03-29-2014, 01:02 PM
I asked a member a similar question this week and he couldn't help me though he builds motors regularly. I did some research last two days about how carbs work and Bernouli's principles and now I know why he and most others cant help. No two machines even with identical setups require exact same jetting. Add to that humidity, altitude, load on the motor, intended use, octane, and many other variables like motor and accessories and its impossible to jet something over the net or the phone. A quick call to Sudco confirmed this. Thats why its tough to get anyone to tell you what jets to buy especially with the possibility they might be wrong and you waste money.
Ghostv2
03-29-2014, 01:15 PM
I asked a member a similar question this week and he couldn't help me though he builds motors regularly. I did some research last two days about how carbs work and Bernouli's principles and now I know why he and most others cant help. No two machines even with identical setups require exact same jetting. Add to that humidity, altitude, load on the motor, intended use, octane, and many other variables like motor and accessories and its impossible to jet something over the net or the phone. A quick call to Sudco confirmed this. Thats why its tough to get anyone to tell you what jets to buy especially with the possibility they might be wrong and you waste money.
I can figure out the sizes myself, i already know nobody can help me as much as i would like. I just need to know which ones to buy. I need someone to show me which jets are for the 225dx. There is 4 pages of various jets. I suck with carbs. Get what i mean?
There is a good writeup on jetting that is a sticky hear, start reading! Get a better understanding of how they work and it will be much much easier for you to figure out. You should be able to balance your idle between your idle screw and air/fuel screw..make all adjustments at operating temputure. Small increments. If you find either screws maxed in or out to achive proper idle then it will be time to change pilot jets dependent on wich way the screws are, im not familiar with your perticilar carb but being a 4 stroke. out on the air/fuel screw should be more fuel in less. Pull your jets to figure out what you need..will probably be the itybity short ones, its easy to see the differnce, or call sudco.
Dirtcrasher
03-29-2014, 01:26 PM
If you suck with carbs, you need to get more comfy cozy with them.
Did you read the "sticky" about jetting. I think DaMMIT! made one.
Then tell us what you changed and at what throttle position? it no longer works??
Main? Pilot? needle? starter? air screw?
Ghostv2
03-29-2014, 02:03 PM
I appreciate the willingness to help and get me going in the right direction but I just need to know which jets to buy. I've been messing with this carb for the last month trying to get it running 100%. I've adjusted the needle clip, I've tried the idle screw. I've done most of this. I will admit the only thing I didn't do is mess with the air mixture screw. I will read up what you suggested about the carbs.
I know for a fact it is jetted wrong. It has too big of jets in it. It had a DG exhaust and the air box removed with a clamp on filter in place. I have put a air box back in it. I'm sure it requires it to be rejetted. So if anyone with a 225dx understands what I am asking I appreciate any insight on which jets to buy. Soon I'll go down and take a picture of the jets so someone else could help. I don't mean to sound rude of I am, I just simply need to know which jets to buy.
Toaster556
03-29-2014, 03:00 PM
You need Mikuni round style jets for the main, and the pilot jet should be a VM28/486 style, but I'd like a picture to confirm. Both are common, easily available online, or thru your local dealer.
I use Niche Cycle Supply for most of my jetting requirements, the pilot jets you need (provided they are indeed VM28/486) are found HERE (http://www.nichecycle.com/ncs/index.php/frontpage-slider/vm28-486-vm28-486-pilot-jet-by-mikuni.html), main jets HERE (http://www.nichecycle.com/ncs/index.php/categories/fuel-air/jettting-tuning/main-jets/n100-604-n100-604-main-jet-by-mikuni.html) on their site
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