HMF Slip on and Jetting advice/help

[ben300]

ok, i know theres a bunch of threads on here about jetting help and guide lines and honda400ex2003 (aka steve haha) even posted a recommended guide line chart for different jetting applications, depending on pipe, and air box and yada yada...but what im looking at is what you guys are running.

i recently decided to do some mods on my basically bone stock 400......i purchased a used dg exhaust off a buddy. had to clean the exhaust up and repaint it cause it looked like ****! anywho, i ran that wth stock air filter and airbox lid on.....and i rejetted it from the stock 148/38 to 152/40 (main/pilot)

i then wasnt satisfied with it enough so i ordered a unit filter/and outer wear, removed the air box lid, and following the advice i got from on here, wiht a little testing, i increased the jetting to 158/42..

so..yet again, is till wants happpy enough. i just felt the DG looked like ****, and it didnt quite bolt up right. had some special monting brackets that looked ghetto rigged and didint quite fit right over teh head pipe.....i then determined that this exhaust wasnt probably for a 400ex, and was for somethign else or was a universal honda pipe (leave it to dg to make such a thing:rolleyes: :huh )....

any way, i decided to not be a cheap *** and bought an HMF performance series slip on brandnew from HMF...they recommend running 165-170 main jets!:eek2: , and give no advice for the pilot or the fuel screw......


so what i am asking, is you guys, CJM, honda400ex2003, dxcody...whoever else wants to chime in....what do you guys think you would run? do you any of you guys have experience wiht this slip on or have run it in the past? currently? i know ill have to play around with the jets, but im just trying to get a baseline to see waht jets i may need to purchase..... i currently have a 148,150,152, 155, 158, and a 160 mains, and i have a 38, 40, 42, and a 45 pilot...

ill be running slip on, stock head pipe, air box lid removed, unit filter, outerwear, and possibly have he snorkle removed with the hole plugged (currently have snorkle removed, no plug)

[CJM]

Id start at 165 and see what happens from there. Chances are you wind up at a 160ish main. Its honestly hard to say b/c of elevation, air temps, etc. In my case Steve may live halfway across the country but the temps and elevation are actually close enough that whatever he runs I can run the same.

I would also put the 42 pilot in as well. You will probably windup at 2.5 turns for the fuel/air screw.

Reading the plug would be key, of course you want the tan/brown color.

[ltz480]

I run a 42 and a 165 main with airbox lid off and 2 and a half turns out bike runs great

[erik420]

I am jetting my ex for basicaly the same mods. I have a 42 pilot and a 160 main. I have not touched the air fuel screw. I have a slight bog somethimes. Going to adjust the screw some to see if that helps. If not im going to drop it down to a 158. Im curious as to where you end up. Subscribed !

P.S. Do u go clockwise on the screw to lean it up some?

Erik

[ltz480]

lean is in rich is out

[ben300]

thanks for the responses guys.

i went and re-jetted it tonight. i only had up to a 160, so i stuck that in and i already had a 42 pilot in.

before the hmf, with the 158 main and the 42 pilot, it ran real good at the top end with the dg, but was bogging just slightly on the bottom end...

with the hmf, it was perfect on the bottom end...no bog, not lean, would pic the front end up no problem...however, it started to get lean in the mid range to to the top end with 160.

so i have a 162, 165, 168, and a 170 on the way from rocky mountain... that should be here Thursday, so this weekend im gonna ago with what you guys say and try out the 165 and play from there..

i may even throw a 45 pilot in, since i have one, and see from there how it reacts...... and ill probably play with the fuel screw i suppose


thanks for all the responses

[CJM]

If its bogging in the mid range your needle needs to be adjusted. 3rd notch should suffice. Id try upping the jet one or two more sizes just to be sure however before you mess with the needle.

Upping the pilot will make it bog down low if its too rich.