[Kreylyn]

It was like this when I bought it, I have no idea about where the bike's from/ the exhaust on it.

*pic of a Kerker 4-1 aftermarket exhaust*

Okay, so to you...

It's always been doing it, it does have an aftermarket higher flowing exhaust, and you don't know the history of the carbs. Well, you will need to verify a couple of things first.

Stock airbox, or did someone put on pod filters. If stock airbox, does it have an OEM filter?

(remove the seat and gas tank. Does it have a big black box attatched to the carbs? )

Is it a CA model?

(At the forward most where the tank "hooks" on, just under that is there a couple of canisters there?)

Does it have a jetkit installed?

(remove the black cap top off of one of the carbs, CAREFULLY to not loose the spring inside. Pull the underlying rubber gasket/slide piece out also carefully. Inside that, there is a "needle". Push the needle up. At the top of the needle, is a "clip" around it, with 2 plastic pieces on either side. Larger one on top seats the spring. How many grooves are there in the needle? Is the tip of the needle gradualy smaller, or is there a definate abrupt change in size?)

Bring back that info, and we will probably be able to resolve the issue for you.

My GUESS off hand... it's not jetted, with the aftermarket exhaust... so your running very lean, and have alot of afterfire. Resolution to that, would be to instal a jetkit. Yes, running that lean could cause engine issues due to heat.

Krey

[notec]

Also check for exhaust leaks. Make sure all fittings are sealed. I use Copper Seal on mine.

[puryie]

Airbox is stock OEM filters, pretty sure I don't have a CA model, Posted a pic anyways.



I have 5 gooves and it's in the second to top goove, I'm guessing the needle is stock?




Sorry for all the pics ><

[ADyingBreed]

Airbox is stock OEM filters, pretty sure I don't have a CA model, Posted a pic anyways.



I have 5 gooves and it's in the second to top goove, I'm guessing the needle is stock?




Sorry for all the pics ><

That would be a jet kit. Stock needles only have one groove IIRC.

[Psycho1]

Definetly not the stock needles, so it has been jetted before, most likely that's where the problem is (unless it just has a spark plug fouling). Still need to find out for sure if the air filter is the stock plain white paper type element, or a K&N which would have a screentype mesh around gauze and should be oily looking.

[Kreylyn]

Factory Pro jet kit, probably set up as a stage 1.

Any hesitation or smooth acceleration?...

If it's smooth... your set up right, and the popping your hearing is normal.

Krey

[Psycho1]

would only be normal if he was only hearing it under deceration. He said it's popping at 50mph or so under steady throttle.

[Kreylyn]

would only be normal if he was only hearing it under deceration. He said it's popping at 50mph or so under steady throttle.

Then it's running lean, and it's afterfire... shim the needles ...

Krey

[puryie]

The filter is stock paper.

The bike hesitates a bit when it's under 4k, after that it clears up.

[Psycho1]

That's what I was thinking, drop the clip one notch at a time to raise the needles and see if it clears it up.

[Kreylyn]

That's what I was thinking, drop the clip one notch at a time to raise the needles and see if it clears it up.

Yes, you may need to be using a #4 brass washer to "shim" it, and go 1/2 steps to fine tune it, but I would start with a full step down.

Krey

[puryie]

Thanks guys, you really saved me on this one

So I moved all the clips down one and it ended up moving the afterfire into the 3-4k range as opposed to the previous 5.5k. Do I just keep moving the pins till the afterfiring stops?

On a sidenote, would messing with the A:F screw help to alleviate the problem?

[Kreylyn]

Thanks guys, you really saved me on this one

So I moved all the clips down one and it ended up moving the afterfire into the 3-4k range as opposed to the previous 5.5k. Do I just keep moving the pins till the afterfiring stops?

On a sidenote, would messing with the A:F screw help to alleviate the problem?

A/F screws mainly affect the 1-3k range, then there is a transition from the pilot jets to the mains (needles) from 3-4ish, then over 4k it's mostly the needles.

I would go down 1 more, test on all rpms... if everything is smooth, your set. If you see any issues for higher rpms (hesitation or surging) then drop back 1/2 slot. (go back 1 slot, and add a shim).

Krey

[puryie]

A/F screws mainly affect the 1-3k range, then there is a transition from the pilot jets to the mains (needles) from 3-4ish, then over 4k it's mostly the needles.

I would go down 1 more, test on all rpms... if everything is smooth, your set. If you see any issues for higher rpms (hesitation or surging) then drop back 1/2 slot. (go back 1 slot, and add a shim).

Krey

I was gonna post this in a new topic, but now is as good a time as any.
I have idle problems with my bike, if I drop the idle below 2k it'll idle at like 1.5k then drop down to 1k after like 10secs, and it'll drop again after that. My buddy said it might be a vacuum leak, but I figured I would ask you guys. Thought it might be related to the A:F, maybe?

[Psycho1]

ok if the idle is hanging, and you have checked for vacuum leaks around the intakes and carbs, you could start by checkign the a/f screws, hopefully they already removed the caps then they put the jet kit in. Set them at 2 1/2 turns out from lightly seated to start, and see if that helps the idle drop quicker.