sputters on lowend/need help with pilot

[ridein'red7]

as the title says its just sputtering when u hold it before 1/8 throttle do i need to just keep playing with the air fuel screw? is it lean or rich it goes away when i give it gas im leaning towrds it is rich because wth the choke it stalls out haha

[honda400ex2003]

sounds too rich to me. what did you have in it again? go one smaller or go down some more on the f/a screw. you could go in half a turn and see how it does. you gotta be getting closer with that thing huh? steve

[honda400ex2003]

possibly 3/4 turn. you had a 42 i think, so around 2.5 turns out would be a guesstimate. lol steve

[ridein'red7]

its a stock slow jet and that is the only thing holding me up well beside the stupid electric start

[honda400ex2003]

did you try the f/a stuff at all. it will probably need a 40 or 42 pilot then. steve

[ridein'red7]

i tryed adjusting it out ade a lil worse than got a 300$ fine for loudness and un permissional exess when i do and they said iout ran them when iv only riddin the damn thing 2wice lol but do i need to bring the a/f screw in?

[honda400ex2003]

bummer on the ticket. lol yeah go in then go a quarter turn at a time till it goes away. ill get the correct adjustment procedure for the f/a screw. it is also in the manual if you have it. steve

[ridein'red7]

all right ill try it tomaro and i putting my quiet core in now haha if not do i need to richen the pilet

[honda400ex2003]

heres one version

OK. On to the procedure!


1) Warm up the engine to full operating temp.

2) Turn up your idle a few hundred RPM using the throttle stop screw (basically you want a fast idle). This will make it easier to hear small changes in RPM. Watch for overheating--pointing a big shop fan at your engine will help it from getting too hot during the fast idling. The whole procedure shouldn't take too long though.

Each time you change the screw setting 1/4 or 1/2 turn or so, wait about 5 seconds to let the idle speed normalize. It usually take the carb and engine a moment to react to the change.

3) Turn the fuel screw IN until the idle starts to drop and miss. The engine should die if you bottom out the screw. Your pilot jet is too big if it doesn't die when the screw is bottomed out--it should die before it gets that far in.

4) Then begin turning the fuel screw OUT. The idle should peak and become smooth. Keep going and look for the idle to begin to drop/miss again.

5) The goal is to find the setting that provides the highest and smoothest idle. If it's unclear exactly were that point is then set to the midpoint between step #3 and step #4. For example, if the idle starts to drop at 1 turn out and starts to drop at 2 1/2 turns out then 1 3/4 of a turn out should be the correct setting.

If the peak/smoothest RPM is reached somewhere between 1-3 turns then your pilot jet is correct (the 1-3 turns applies to most carb types). If you end up less than 1 turn out then your pilot jet is too big and you need a smaller one. If you end up more than three turns out or the fuel screw seems to make little difference as you continue turning it out than you need to go up (bigger) on your pilot jet.

To re-emphisize: If the idle never drops when you're turning the fuel screw in, you need a smaller pilot jet. If the idle never drops when you're turning the fuel screw out, you need a bigger pilot jet.

Typical fuel screw settings are in the 1 1/2 to 2 1/2 range.

6) Once you've got the fuel screw set, re-adjust your throttle stop screw (idle screw) to an appropriate idle speed.

And that's it! Your pilot circuit is now VERY close to ideal. From here you can experiment with how small adjustments affect low-end (i.e. small throttle openings) response and make adjustments for weather. The hardest part is usually gaining access to the screw while the engine is running. Also, you may really have to listen carefully to detect the rpm changes in the idle. 100 or 200 rpm differences can be tough to detect when the change happens over several seconds.

steve

[honda400ex2003]

same thing from the manual. 3rd post.
http://www.exriders.com/vbb/showthread.php?s=&threadid=413556&highlight=fuel+screw+adjustment


if it ran worse with the f/a turned out i would say that you dont need a bigger pilot. does it pop excessively when you are going pretty fast and let off the gas? steve

[ridein'red7]

it doesnt seem to pop a lot maybe once and a great while just when u just give it the slightest gas its boggy bad and quits out unless u pump it

[honda400ex2003]

those two descriptions seem to imply 2 different things. one says rich other says lean. the pumping has me worried about being lean, while the f/a out has it shouting rich which is hard to believe on a 38 pilot. Are you doing this when the machine is fully warmed up? All of this seems to be leading me to think that you will indeed need a bigger pilot but you said it got worse when you went out on the f/a screw. if you have a 42 try it out. go 2.5 turns out and see where it leads you with the 42.. you can then do the above procedure with that. really with that procedure you should be able to run almost any size pilot and have it come out close. if you dont have one, do the procedure above and see how it runs. i ran a 48 pilot at one time lol i was at around 1.25 turns out on the f/a but it worked. lol this could also be leading toward the needle being dropped but you said it runs good after that so it limits that. steve

[ridein'red7]

yea i am doingthis when it is warm but see i cant keep it at idle because the idle line broke so its adjust but i think the piolet wont let it idle and if it stalls i have to push start it again and that starter is pissing me off is itbecause i have no decomp?

[honda400ex2003]

if you have a stage 1 or 2 you wont need a decomp mechanisms with the spring and plunger. they are actually supposed to be out so hopefully they are. i would get that other stuff fixed first, then you can get it dialed in. it will be much easier to work on when you can hit the button and adjust the idle up high enough to keep it running. lol steve

[ridein'red7]

it is a stock cam with the de comp lobe off and oil holes welded because i lost the spring but when the starter has no gears it spings very fast and acts normal

[honda400ex2003]

lol i still think you need a new one. just because it spins with no torque on it doesnt mean it will when there is. as for the cam, im not sure about that one. lol steve

[ridein'red7]

yea its a stock cam i posted earlier and someone said press the lobe off so i did and than tigged the holes shut and ill try my buddies motor and i rode it to day and when ijust baley give it gas and hold it for a second than goose it it bogs than goes like it is lean

[honda400ex2003]

preobably is but you can keep it running lol. get a 42 and stick it in there. steve

[ridein'red7]

k steve all see what i can get lol and it smokes a little for about about a min til its warm and its fresh rebuild and fresh valve seals!?!?!?!

[honda400ex2003]

i think it is a series 16 that will work if you have to buy them. take the one you have with you to compare them. the 16 is a bit longer head but still works fine. steve

[ridein'red7]

for the slow jet? and do u know y it smokes is it becasue its not realy alot of run times?

[honda400ex2003]

nah lol i was just talking about the pilot jet series. lol not sure on the smoking. Hopefully it will be cleared up with the bigger pilot. lol hopefully your rings are seated fully, they may not be yet causing some blow by into the cylinder which is no big deal it would jsut need to be ridden enough to get the seated. it all depends on amount of time and how it was broke in or if it is not broke in. hard to say. steve:confused: :confused: :confused:

[ridein'red7]

ok and i littlealy have gona easy thre w the throtall never full for a time just a split second and maybe done it 3 times but loads on it

[honda400ex2003]

you gotta get one issue done at a time instead of trying to work on 4 all at the same time. too many variables to mess with and have problems with to do anything with jetting imo. pop starting a fresh engine is probably not a suggested break in technique or good for it in general. not being able to adjust your idle makes tuning your pilot circuit near impossible, having a fresh engine that gets revved without a load on it probably isnt real good either the rings seat from building pressure in the chamber and without a load on it, it is hard to stress the engine and create high chamber pressures. anyway, i guess ill keep trying to help out lol. only so many things i can do though without being there to work on it and ride it to see how it runs. i ran my 416 for 2 years on the 38 pilot at 3.5 turns out on the f/a screw. each engine is different and will require more or less gas and air depending on where it is and what is done to it. I didnt run a 48 or 42 until i took my choke out for the summer. i ran 1.25 turns out on the f/a with the 48, around 2.5 with the 42 for a few weeks. i then put the choke back in and went back to the 38 and 3.5 turns out for the winter. yours is giving mixed signals, (it is probably a woman) and is saying one time it is rich, the next is lean. when it runs worse with the choke on it is too rich, but when it is popping on decel and smoking white is shouts lean. imo it has to be full operating temp which can not be achieved from only riding 10 minutes, it would have to almost idle that long. I ride for 15-20 minutes before 200 degrees is reached. this for me is right around full operating temp. you could start testing at around 150 but it is still on the cold side for any real diagnosis. the engine richens up when warm so it could pop and such when cold and be perfect when it gets warm. this is really what the choke is there for, to cover the lean conditions of starting until it warms up. no offense to you cause this is not toward you. just a common ideal of mine and how i feel about what goes on in an engine. just my opinion, steve

[ridein'red7]

i am just not a four stroke guy and i mean load by like no hills or jumps just feild runs haha and ithank you for what u have done i am gona try a diffrent starter motor because that would really hel p allot thhem i can tune!

[honda400ex2003]

i go by the practice style moto type riding with varying rpms for 15 minute intervals.

http://www.mototuneusa.com/break_in_secrets.htm

i did about 6 of them though instead of 3 sets. I let it cool down good inbetween each of run and do it again. even with it lean on the pilot it wont hurt it. the majority is close enough to be fine for 15 minute sets. That is just enough to get it up to temp and run it for 7-8minutes when at full temp when riding on the hard side I would be more worried about getting it broke in first. i dont usually ride hard when first starting to allow time to warm up but when you are breaking in there isnt really alot of time for that. no problem on the help you know that. lol i am on to do just that i guess. lol you gotta get it to start up then you can get it going from there. you could probably test the starter if you take it to auto zone or something. they can tell you if it will take a load or not. steve

[ridein'red7]

thanks steve the nirgbor kid has a stocker so im gonna rob his and try it hahaa