dynojet / kehien conversion?

[dave07ex]

I have an '08 400 with a full exhaust, alum. airbox (no lid) w/ k&n, stock carb. DJ "recommends" a 170 main (their number) for this setup. I think this is way too big for my particular setup. Any idea what main (in DJ numbers) I should start my tuning with? I did purchase K-H 40 & 42 pilots, so I'm covered there.

[bkelley]

This should help you.

http://www.jetsrus.com/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm

170 DJ is way too big, that's a equivalent to a 190 Keihin. To be honest, I wouldn't even put Dynojets in. Stick with genuine Keihin jets. With your setup, you should start with a 155 Keihin main.

[honda400ex2003]

i would start with a 150 dj. I dont think you have a 150 in there and believe it is a 152 so go with that instead. needle on the 3rd clip, 42 pilot, 2.5 turns out on the f/a to get you started.

http://www.exriders.com/vbb/showthread.php?s=&threadid=445695&highlight=jetting+placement


steve

[bkelley]

A 150 DJ is still pretty big, Steve. That's a 165 Keihin. He needs to be at a 152 or 155 Keihin with those mods.

[honda400ex2003]

he is running a full exhaust with an open lid. it will be more than a 150 or 152 that is what people fun with a slipon and lid on without a filter. but hey he can do as he wants. mine is just an educated guess anyway. i ran a 138 with my slipon and the k&n with my filter on... steve

[bkelley]

I read over the full exhaust part, was thinking he was running just a slip on. In any case, a 170 DJ is way too big. And I still say he should stay awa from Dynojets. You and I both know it only leads to problems haha.

[honda400ex2003]

LOL WAY TO FREAKING BIG lol I love those wonderful dj directions. they blow... steve

[honda400ex2003]

if possible send it back and get a 160-162-165 and a 168 and you will be fine. i totally agree with B that nothing good can come from dj stuff. lol we both went around and around trying to get our 416s dialed with the dj crap. steve

[f4iracer]

Originally posted by honda400ex2003
LOL WAY TO FREAKING BIG lol I love those wonderful dj directions. they blow... steve

this goes both ways.

I have to say, i was buying the jets like you all suggested, so i bought a 152 keihen main and that wasn't enough. I ended up having to buy the dynojet kit so i could get the adjustable needle. Also, the kit comes with all the jets you'll need so you can easily tune once u get the kit.

My quad required an adjustable needle and the d shaped tool that came with the dynojet kit. Without this i would not have been able to tune it correctly. i did everything with the a/f screw and nothing worked.

I had it out yesterday and it was about 45 degrees out. It was popping a little on decel so i think i need to richen up my main jet one more step. Right now i have a 152 keihen in there, i'm hoping the conversion chart is somewhat accurate because i'm going to put the 155 keihen equivelent in dynojets. I believe it will be a 142 dj.

[dave07ex]

Thanks for the great input. I figured dj's recommendation was way too fat for my setup. Hopefully I'll get this thing dialed in mid-week. At least I have a sold starting point now. Thanks again.

[dalejiw25]

Popping on decel. indicates a lean pilot condition, also if you buy a rebuild kit for a '99-'04 carb you will get a slotted a/f screw and an adjustable needle included for far less $$ than you'll pay for a POS DJ kit. The older rebuild kits will work on the newer carbs. JMO.

[dave07ex]

Well the carb is off, awaiting the new pilot jets to arrive from rocky mountain. Gonna try a 165 main w/ needle on 3rd clip and a 42 pilot, 2.5 turns out on the screw, to start. Choke is gone now too. Should have the pilot in by Wed.

[f4iracer]

Originally posted by dalejiw25
Popping on decel. indicates a lean pilot condition, also if you buy a rebuild kit for a '99-'04 carb you will get a slotted a/f screw and an adjustable needle included for far less $$ than you'll pay for a POS DJ kit. The older rebuild kits will work on the newer carbs. JMO.

you sure my pilot is lean? it only pops after spanking it full throttle or when it's cold. once the quad is warm it rarely pops unless it's below 40 out.

i've got a 40 pilot and i'm 3 turns out on the a/f screw so there's no way i'm lean on the pilot with juust a slip on and an air filter.

I'm lean on the mainjet, i'm gonna throw a bigger one in and then i'll report back.

i paid 50 for my dj kit and it's got everything i'll ever need. i won't have to ever buy another jet again. like i said i had to have the adjustable needle anyway.

[dave07ex]

Agreed, I like the fact that the dj kit came with all those jets, the adj needle and the f/a screw tool.

[honda400ex2003]

just for future reference Jets r us has normal keihin jets in a kit also. You will find that even though there are a ton of jets in the kit, most of them will not be close enough to have it run correctly or shall i say at its peak. it will run fine with them but once you start to get into bigger bores and such where the bigger jets are needed the kit wont have them anyway. they are great for stock engines with an exhaust and filter though. steve

[f4iracer]

well i got the stage 1 and stage 2 setup so it's got like 8 or 10 jets, fine for me until i do a big bore which i probably never will.

it's not a bad option to buy the whole dj kit. in the beginning i read on this forum and everybody said just to go buy them cheap one at a time. i wasted time and money doing this because i STILL REALLY needed the needle and adjustment tool.

the jetsrus kit is not cheaper and it doesn't give u

[honda400ex2003]

i know what is in it... I have the same kit as everyone else sitting in my garage. as i said for the exhaust and such it is fine. actually it does a great job with a pipe and filter combo if you get the main right. it does blow that the new carbs dont have adjustable needles in them- way to go honda. that was along with those bold new graphics and fenders a few years back. These 2011 better be freaking awesome... thats all i have to say. they have quite a few idiotic moves to make up for. steve

[dave07ex]

No jets yet, maybe tomorrow or monday.

[dave07ex]

Got the 42 pilot in and it seems to be just about right at 2 turns out. Gotta do more breaking in before I can see where I need to go with the main. Got a 165 (dj equiv) in there now. Needle is on 3rd clip. We'll see...