need help asap Re:42pilot vs. moving needle clip

[platinum350]

Ok, here is my dilemma. I just received my HMF slip on and want to put it on now so I can have it jetted before I ride tom. While I was tearing the carb apart I figured I would put a 42pilot in it to make it easier to star while it is cold. Well, I am having a difficult time getting one right away w/ out spending too much money for overnight shipping.
I was told by HMF that by movin the needle clip to the second from bottom posistion would do the same thing. Is that true? I should just move the clip and forget about the 42pilot?
Any help w/ this is much appreciated, thanks.
Joe

[F-16Guy]

Moving the needle clip won't do the same thing as changing the pilot jet. The pilot jet controls a totally different fuel/air circuit than the needle. Changing the the pilot jet will affect idle to just above idle through richening or leaning the idle circuit, then the needle takes over as the slide starts to open and allow air in. You move the needle to make adjustments from about 1/8 to 3/4 throttle; anything below is the pilot jet or air screw, anything above is the main jet.

[cals400ex]

hey joe, his response sounds familiar doesn't it? ;)

[zlam27]

get either a #40 or #42 pilot, it will help out a lot. i have a 42 with my pro-circuit T-4 and my friend has the stock 38 with his HMF pipe and in the winter, mine will start and idle 10x better than his. it really, really helps out.

zach

[platinum350]

LoL, it sure does Cals...this was before we spoke. BTW, I ran w/ the needle in the second posisition from the bottom w/ a 165MJ and left the pilot alone(for now). She seems to be running pretty damn strong. The HMF, opened airbox, rejetting the carb and going w/ a 14t front sprocket really woke my 400 up.

[jahaiap]

i just got an hmf slip on. with stock jetting and a k and n it ran fine and i noticed a difference in power. the place i bought it from sent the main jet that hmf recomended. i decided to put it in. its a 165 i think. they also said to change the needle clip settings. the way i found it runs best is the opposite of the setting they recomended, i think. it is two clicks down from the top of the needle as it is positioned in the carb( the blunt short end). i also changed the air screw or fuel screw setting like they said to do. it needed a couple more turns than they said to run properly. it still has a small amout of popping when im decellerating. i dont know a whole lot about carbs, but the adjustment i did to the needle really seems wrong to me, but it makes it run right. does this jetting sound right? any clues how to get the popping to go away? im in sw fl, pretty much on sea level...thanks

[mattonln]

dude, the popping means you are lean..... change the needle to what they recommend.... they know what they are talking about.... if that doesn't work, go up 1 or 2 sizes on your main jet...

[cals400ex]

Originally posted by jahaiap
i just got an hmf slip on. with stock jetting and a k and n it ran fine and i noticed a difference in power. the place i bought it from sent the main jet that hmf recomended. i decided to put it in. its a 165 i think. they also said to change the needle clip settings. the way i found it runs best is the opposite of the setting they recomended, i think. it is two clicks down from the top of the needle as it is positioned in the carb( the blunt short end). i also changed the air screw or fuel screw setting like they said to do. it needed a couple more turns than they said to run properly. it still has a small amout of popping when im decellerating. i dont know a whole lot about carbs, but the adjustment i did to the needle really seems wrong to me, but it makes it run right. does this jetting sound right? any clues how to get the popping to go away? im in sw fl, pretty much on sea level...thanks


what slow jet are you running? how many turns out on the fuel screw are you? are you using the stock B44A needle?

[jahaiap]

im using the stock needle and slow? jet. do you mean pilot? anyway, im still going to check the plug to see whats really going on but if its not right im going to get a jet kit and have a shop jet it. i think im out about 4 turns on the screw.

[cals400ex]

yes, sorry for the confusion. i think what everyone calls the pilot jet is actually termed the slow jet.


i would put in a 42 pilot jet. also make sure your 4 turns out and not 2. the fuel screw needs to rotate a full 360 degrees for it to be considered one full turn. if your 4 turns out, you definatlely need a larger pilot. you should go to a larger pilot if you run more than 3 turns out actually.

i can't see how the bike runs right with the needle clip in the 2nd slot from the top. i would run it in the 3rd or 4th clip from the top so your not lean. you would have to be lean in the 2nd position.

[jahaiap]

i rode it today... this is what i did, i couldnt get a new spark plug so i cleaned up the one that was in it. i made sure it was gapped properly. i rode it for two or three minutes. at the end of that ride i was running wide open in 3rd and pulled in the clutch, rolled to a stop and checked the plug. my friend told me later i should have killed it while coasting right after i pulled in the clutch. anyway, i shut it off and pulled the plug. its brownish black. not brown and not sooty, kinda in the middle. so itsa little rich right. what do you think?

[cals400ex]

here is the jetting i would start with:

keihin 155 mainjet

3rd needle clip position in warm months, 4th clip position from the top in the cold months

42 pilot jet

2.75 turns out from lightly seated on the fuel screw


you could be rich on the fuel screw if your a full 4 turns out.
i assume your air box lid is on? also, the elevation and temperature you ride at is important to know so these were just suggestions that i gave you.

[jahaiap]

ok, i will most likely try that two weekends from now, but for next weekend i will ride it like it is. we are going out of town for a big riding trip. i think it will be alright until then. by the way... it never really gets cold here ( i think you are from a colder climate, the coldest i would ride in is about 60 anyway), and my evelations is practically nothing. i live in southern florida across the state from miami. i am about 8-10 miles from the shore, my elevation is only about 12 to 15 feet i think. thanks for the info, ill probably order a jet kit next week because the only jets i have are the stock main and a 165 main. i do have my airbox lid on. thanks