Jetting

[Rohr397]

Well with the weather change, my jetting is officially running lean. It's popping on decel a lot. I don't know what to do, I mean obviously rejet, but I am terrible with jetting. Last time I tried to get my jetting right I managed to completely mess up my carburetor and the jetting went way out of whack. That resulted in me taking it to the shop.

That being said, do I wing it and try to get it dialed in on my own or do I throw in the towel before things get worse and take it to the shop?

I know it sounds stupid but I really have bad luck with carburetors.

If I'm gonna give jetting another go, where should I start with my jets? I know that nobody can get it exact but a rough estimate would be good.

I'm constantly under 3000ft sea level, usually below 1000ft. I've got a Motoworks slip-on, stock header, K&N filter with the lid removed and the carburetor is bored with the choke removal mod.

Thanks

[pdpdrummer123]

whats main jet are you running right now and where is your clip at on the need what notch?

[Rohr397]

In all honesty I've never been into the carburetor since I bought the quad. Whoever originally built it did the jetting.

[pdpdrummer123]

okay well with the choke delete youll have to make sure the pilot jet is 48. And for the main jet I would get 152 155 157 and 160 kehin hex jets and mae sure your needle is three or four notches from the top and go from there don't be intimidated you can do it! =]

[Rohr397]

Alright I'll give that a go this week and see if I can get it worked out. I'll also take a look at what jets are currently in there.

[pdpdrummer123]

alright man sounds good let me know if you have any problems ill try to help you through them!!

[Rohr397]

Awesome thanks!

[Rohr397]

UPDATE:

Pulled the carburetor open. Checked all the jets, had a 165 main and needle clip at the 3rd position. My pilot jet however, was still a 38! :eek2: I threw in the 42 pilot, warmed it up and did a test ride. Not a single pop. Glad that was easier than my last jetting attempt.

[ajw2685]

How are people running a 42 pilot? Seriously.

When I had an open air box, FMF header and Lexx MXe exhaust with race tip, I still could NOT run a 42 pilot. It was just too much fuel. I could not tune it in at all. If you even blipped the throttle at idle it would belch, choke, cough and die. I put my 40 back in with around 2.75 turns out and perfecto.

[Rohr397]

I'm like right at sea level so that's why.

[JOHNDOE83]

You can jett anyway you like really, I have a easy and very good way to jet thats recommended by top name manufacturer's.

By jets in incriments of 5, from 155-185 " I doubt with a mostly stock 400 youll be over 185.

Start with 185, it "should" not fully rev out and break up from being to rich in the tope end, then go down in jet size till it stops breaking up and fully rev's out. "main jet is set"

For the needle, 3rd notch seems to be fine for even highly built motors.

For the pilot a 42 should be fine, a 48 is to much IMO. I ran a 42 with a 440 with no choke and it was perfect. "at sea level"

The popping on decel is from the pilot jet being to lean, you could turn you a/f screw out some more to compensate for that. I highly recommend the 42 pilot 3 turns out though.

[pdpdrummer123]

ya sorry about that i meant 42 i dont know why i put 48. lol I run an hmf full competition series exhaust with a choke delete. air box lid on with a outwears lid and sparks supercharger filter and my jets are 162 main 42 pilot and the clip three notches from the top also have a sparks timing key which was a great investment! highly suggest it! runs great!