what else couldit be??

[ryder_trig]

Last week I added a yoshi rs2 slip on. I already had the k&n w/out the lid and sperks +6*. Jetting was 42 pilot & 150 main. I bought a 152 & 155 main and 45 pilot and have been messin with it for a few days but havent had any luck. I searched this forum for a few days lookin at all your set ups and thought I was in the right ball park. Iv torn the carb apart and cleaned it thourally. It wont idle, pops and dies at just about any throttle and when it does rev it pops and back fires. :grr: Am I too rich? What else could it be?

[hypersnyper6947]

you have to ride it and tell us what it does to correctly diagnose your jetting, revving it wont tell you anything

[hypersnyper6947]

make sure to take mental notes as to how it performs at all levels from zero to WOT

[bigbad400]

there is no way you should have a 45 pilot in there with those small mods i have a 11:1 440 ported and polished with a full pipe and i have a 45 in mine you prolly really didnt need to mess with the pilot at all, id put the 42 back in and the 152 and run it down the road once and see were it stumbles or what it does. you never change more than one variable at a time, start with your main and then when its close use the air/fuel screw to fine tune it.


in the most popular ex threads at the top of the page there is a jetting help section. i suggest you read it thoroughly, it will help alot.

but you only added a slip on pipe. maybe one or two bumps up on the main and you should be good.

[ryder_trig]

Nice. Ok I'll put the 42 and the 152 back in and a new plug I just picked up and run it down the road (time to annoy the nieghbors again, lol). I'll have to do it friday and get back to you guys this weekend.

[honda400ex2003]

warm it up on the old plug then change it to the new one and ride it. then do a plug chop on it to see how it is doing. steve

[tri5ron]

Originally posted by bigbad400
you never change more than one variable at a time, start with your main and then when its close use the air/fuel screw to fine tune it.
I have always been under the impression that the A/F screw was for fine tuning the idle circuit only, and had no effect at the main jet, circuit functions.

am I wrong here ???

[honda400ex2003]

i would say you are correct, the f/a is mostly for fine tuning. it can also be used to help regulate the pilot circuit too as far as i have understood. I am interested now. it doesnt do anything really to the main or anything to make a significant difference in any of them. steve

[jasonwayne222]

so it ran fine until u changed ur jettin or when u changed the slip on? it will pop and even blow a little fire on decel when u have an exhaust leak, have u done any valve adjustments or reset your timing incorrectly

mostly im unsure about if it ran fine until u changed ur jettin or when u changed the slip on

[katch26]

Ive got the same mods on mine and run a 45 pilot.......def test both yourself and choose yours for yourself. I tried both and (for me) the 45 didn't pop....the 42 was only slightly better than the 40.

[ryder_trig]

Well I was running the stock pipe with a k&n and 6* adv key with a 40 pilot and 150 main and it ran great no popping on decel either. I put the yoshi on and raised the slide needle up to the top clip and it ran smooth but the power wasn't all that great. That's when I started swapping to the fatter jets and it's been lousy ever since. It makes no sense why it ran smooth with just raising the clip but it did. I ran it through the neighborhood with ,like I said, not much power.

[honda400ex2003]

i would go to a 155 then go down to the 3rd clip again, you leaned it out more by raising the clip then added the slip on which made it even worse. leave the pilot alone for now and try that. you should be really close with this. how does the plug look? white? black? brown? white is lean, black rich, brown, you are good. i would say you are too lean right now. just am option for you to try, steve

[ryder_trig]

Ok great. Thanks Steve I'll run that set up and let you know what it does

[honda400ex2003]

good luck, it may need a bit of fine tuning but maybe it will be better than it is now. once you change it, warm it up, change the plug after it is warm and take it for a good 15 minute ride if it seems to be running decent then check the plug again and see how it looks. if you have a few plugs you want to destroy you can do a plug chop at ide, mid and main, to see how each is. just take it for a ride at that throttle position in question then Simultaneously pull the clutch and kill the motor and stop. take out the plug and see how it is.

steve

[honda400ex2003]

found one from another thread

I was looking up a search on "Plug Chopping" And I think this will help you....


plug chopping
the plug chop is an essential step in setting up jetting. not only does it help you get good performance, but more importantly, it helps you make sure yr bike is not running so lean that it will blow up!

1. wind it out! . warm the bike up well (5-10 min) with a new or fairly clean plug, correctly gapped, then wind the bike out in a gear. generally, i like to do this in 3d, but it depends how fast yr bike goes in each gear and where y'r doing this test (trying to run a bike out in 4th is not advisable in, say, a school zone). at least get into 2d.

2. hold it there ... even though you will be nervous, hold it in gear at max rpm for a while... what you are trying to do here is simulate the hardest use the bike will ever conceivably see. if you jet for the most stressful conditions, then yr normal use will be well within safe margins. keep yr hand on the clutch, as you could (doubt it, though) seize if you are jetted too lean to begin with. as always, use yr own judgment!

3. kill it. simultaneously hit the kill switch and pull in the clutch. hitting the kill stops the plug sparking; pulling the clutch stops the clutch from turning the engine over (bringing in more unburnt fuel). thus, you get a perfect picture of what the sparkplug looks like at the moment you hit the kill switch.

4. pull over, pull the plug out you will want to have gloves or a set of pliers, cause the plug will be fking hot!!!

5. read the plug. if the plug is:

black and wet: yr jetting is too rich

chocolate brown: yr jetting is right on!
white and burnt smelling: yr jetting is too lean! upjet now . you might also notice a blistered insulator. this is real bad. you are lucky you haven't hurt yr bike worse!



steve

[ryder_trig]

I pulled the plug this morning when I had a free min to start fresh with a new one. The plug looked black and sooty definitely running rich or not burning all the fuel. Maybe the plug is about to foul, Im about to go back out and mess with it.

[ryder_trig]

Alright here it is. the set up now is 155 main 42 pilot needle clip 2nd down from top and a/f 2 turns out. The idle and throttle response SUCKS up to 1/4 throttle. It wants to idle smooth but it just won't stop popping every 3-5 seconds. So I warmed it up on the old plug then put the new one in while the motor was still hot. I wound it out in 3rd then pulled the clutch and shut it off. I pulled the plug and it looks like an off white so I know Im close maybe it's running a little lean on the main. Now for the pilot I tried the 45 and it was horrible, wouldn't even idle. I called Yoshi yesterday and they recommended the stock pilot jet.:confused:

[honda400ex2003]

i second the stock pilot to see if it gets any better, go in a bit more on the f/a and see if that helps i guess. steve