dial a jet

[beags86]

hey guys! i am new to this site. i have a '02 400ex, k&n filter and no airbox lid and fmf Titanium 4 pipe. stock jetting. i have read all the old treads on this site about the dial-a-jet but i see that that they are mostly older threads. so i ask all you riders out their again. what is your opinion on this product? thanks a bunch!!!

[beags86]

damn near a full day and no help (no replys) and i really thought this website was pretty cool with some cool info and guys on here. so what gives? i know people have used the dial-a-jet. i just wanted some up dated info on it, long term info, but nothing i have never been left out in the cold for a full day!!

[smelly$cat]

I have one on my 440. It was on there when I bought it though, so, I can't tell you if it improved anything. I've never really had to mess with it too much as the elevation changes for the places I ride are not too drastic. FWIW, I just have stock carb and a no choke and it starts easily if I use the stock CDI and it has excellent throttle response. Nice snap. The dial-a-jet is suppose to help with throttle response off idle per the literature I have. I think it's a nice mod. I think you still have to have your bike jetted right in the first place though. Just gives you the ability to make small tweaks to your jetting behavior without completely re-jetting. Did you have a specific question about it?

[smelly$cat]

I was reading one of the 400ex build up articles in the "reviews" section and it looks like they used one. They said they were able to adjust the jetting without changing the main jets at all, which was a bit of new info for me. Here is the blurb.

C&D Racing also supplied us with a product called a "Dial-A-Jet" that would help us tune the carburetor without the hassle of changing out main jets. The Dial-A-Jet works by adding fuel via a small tube installed in the airboot just ahead of the carburetor, using vacuum as a trigger.

[beags86]

was wanting to know if i had to rejet my carb or just use the dial a jet and if cold starts were easier and if the little box that controls the amount of fuel ever broke?

[smelly$cat]

Sounds like you don't have to re-jet, you just use the dial on the dial a jet to adjust the mixture.

I don't think it would have a negative effect on cold starts. Not sure if it helps or not. I know mine starts with out a choke.

I'm not aware of a little box that controls it. It's not electronic at all. It uses vacuum from the engine to suck the fuel in. It pulls the fuel from the bottom of the float bowl on the carb.

[beags86]

well i was meaning i guess the valve. where you adjust the mixture, and i was really hoping it would help cold starts....i live in northern il and the last three days it has been -10 to -30, three days straight (don't tell me that it's doesn't get cold in il!!) granted i haven't been riding but i do ride in the winter, and in the snow. i welded up some skis for the front and have paddles for the back!!, right now starting it a pain, it kills all the time, i can keep her lit if i go right away, but it's hard on the old girl so i would like to keep her at idle til she warms up. with the choke on full,half, or off she will aways dies within three minutes, so i wait and i refire.

[smelly$cat]

I have 2 EX's. The one without a dial a jet dies after idling for a couple of minutes. It can be pretty cold blooded. My other, with the dial a jet, doesn't die at idle when warming up. We might be on to something here :) I can't promise it's the dial a jet making the difference though.

I also have 2 trx 90's. One is a PITA to keep running when it's cold. It wants me to toggle the choke on and off every 5 seconds to stay running. Half choke or full choke, doesn't seem to matter, just wants to be choked and unchoked every 5 seconds. I usually just get it running, toggle it a few times, then put it in gear and hope it doesn't die and putt it around a bit. That seems to get it to idle after that pretty good. The other TRX 90 starts with the choke and will warm up and stay running for a long time without killing itself. Go figure. Both bought brand new. Both the same year/model and color. They probably differ by 1 digit on the VIN, but I haven't checked that :) Probably the tards that assembled one of them at the dealer didn't do something just right.

In my opinion, as far as warm up goes, 3 min is plenty as long as you are easy on her for a few more minutes. Keeping it to 1/4 throttle for a few minutes and I don't think you are hurting anything.

My 2 pennies.

[dave4881]

Originally posted by smelly$cat
I have 2 EX's. The one without a dial a jet dies after idling for a couple of minutes. It can be pretty cold blooded. My other, with the dial a jet, doesn't die at idle when warming up. We might be on to something here :) I can't promise it's the dial a jet making the difference though.

I also have 2 trx 90's. One is a PITA to keep running when it's cold. It wants me to toggle the choke on and off every 5 seconds to stay running. Half choke or full choke, doesn't seem to matter, just wants to be choked and unchoked every 5 seconds. I usually just get it running, toggle it a few times, then put it in gear and hope it doesn't die and putt it around a bit. That seems to get it to idle after that pretty good. The other TRX 90 starts with the choke and will warm up and stay running for a long time without killing itself. Go figure. Both bought brand new. Both the same year/model and color. They probably differ by 1 digit on the VIN, but I haven't checked that :) Probably the tards that assembled one of them at the dealer didn't do something just right.

In my opinion, as far as warm up goes, 3 min is plenty as long as you are easy on her for a few more minutes. Keeping it to 1/4 throttle for a few minutes and I don't think you are hurting anything.

My 2 pennies.

Increasing the size of the pilot jet is supposed to make the engine run better when cold.

[Snipe]

Do a google search the engine has to be lean or the dial a jet wont work if its rich its a waste of money.