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Ok, popping and back firing FIXED!!!!!!!!

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My bike would not start....the carb was all clogged up from bad gas, or who knows what. Anyway, took it to the dealership and the guys there were way cool. Worked on cleaning the carb for a long time and only charged me one hour and also let me hang out in service and check out what they were doing. (Anyone in the Orange Coutny CA area, go to Spectrum Honda to shop there) We got the bike started and running great but now it backfires like crazy when you let off teh gas. It seems to ride fine, but something is not right. Also, when idling, if you hit the choke, the rpms go way up. Not a normal amount, but a lot. I am thinking the pilot cicuit is lean, but the guy cleaned it out 5 times. So maybe a richer jet?....but why would jetting change all of a sudden?

Any thoughts guys? I am pulling my hair out here. I tried a different exhaust and CDI unit off my friend's bike, so it can't be that.

I think I will try his entire carb today to see if it really is the carb. :cry:

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It does sound like a lean condition. Make sure your fuel screw didn't fall out or back out. Also check the headpipe for cracks near the cylinder.

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Checked the fuel screw and tried a completely different exhaust. So it can't be a cracked header. Plus it seems to stop popping as soon as I pull out the choke.

It almost seems like it needs a richer pilot, but why would the jetting change all of a sudden. It ran perfect since I got it 4 months ago. Maybe the pilot circuit has an obstruction in it, but the guy at the dealership cleaned it like 5 times.

I am almost ready to light the bike on fire to give me an excuse to buy an 05. :cry:

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Hey,

It is definatly a lean condition. Kudos to you for checking the exhaust. The jetting will NOT just change with other variables staying the same. If the carb was gummed up, didn't run and then cleaned and it mostly fixed the problem, then it is still the carb. I would not just change the jetting because chances are that when you start changing jetting, putting a bandaid on your problem, you will get more frustrated with the bike!

Don't give up on the bike just yet. There are circuits in the carb that must be gummed up still. If it were me, I would pull the carb, take all the plastic and jets out, get some good carb cleaner you can completely submerge the carb in and soak it over night. This will get the gum out of all the channels. I believe that this will solve your issue...

Good luck, let us know what happens...

:cry:

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Sounds like a intake leak. While it is idling spay some WD 40 or carb cleaner around intake and see if idle changes.

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I feel like a jackass asking, but did you try backing the idle screw out half a turn from where it is?

If the popping stops when the choke is out, its 100% lean condition causing the backfire. Id take the jet out and make sure its not obstructed, or you could just put a new jet in that is the same size to be sure and try it.

You have to start eliminating things as problems.

Start with the air leak first, because its easiest. Then check/swap the jet. :cry:

Youre smart guy, you'll get it :cry:

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That's what I was thinking too, about the gummed up carb. I am going to try my friend's carb today and see if that solves the problem. If that is it, I will have to soak the crap out of my carb. What can I soak it in? Should I just buy carb cleaner in the can and spray it until if fills up a deep bowl? Is there anything I can buy that is in a bottle?

Also, I tried the intake leak test and the idle stayed steady.

I also tried a brand new jet of the same size to no avail.

Shawn, I am not far from you, come take a look at it this weekend if you got the time and inclination to do so. I will buy you lunch and an 18 pack of beer. You gotta let me help you drink it though!!! :cry:

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well the one thing you need to ck is make sure the ft plate on the slide is installed correctly------i cant tell you how many guys put them in upside down-------it can be corrected on the bike,-------when you take it out make sure the squair end in down not the pointed end --------this is more than likely the problem !!!

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I am sure that most of you guys know this, but for the benefit of the new members, bear with me. The fuel screws on 4 strokes are different than the air screws on 2 strokes. On a 2 stroke you are metering air, 4 stroke you are metering gas. If there is a lean condition in a four stroke in the primary circuit, then in order to richen the primary mixure, you have to back the fuel screw out in 1/4 turn increments. On a 2 stroke, you to richen the primary circuit, you have to screw the air screw in.

With that said, if the ciruit is clogged behind the fuel screw with a grain of sand or other obstruction, this could help break it loose. If the obstruction is behind the primary jet or in the jet, the fuel screw adjustment will just make it run worse. Make sure you remember where the fuel screw was to begin with. Good luck.

If I lived near you, I would come over for a PB&J and a Dr. Pepper!

:cry:

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That's what I was thinking too, about the gummed up carb. I am going to try my friend's carb today and see if that solves the problem. If that is it, I will have to soak the crap out of my carb. What can I soak it in? Should I just buy carb cleaner in the can and spray it until if fills up a deep bowl? Is there anything I can buy that is in a bottle?

Also, I tried the intake leak test and the idle stayed steady.

I also tried a brand new jet of the same size to no avail.

Shawn, I am not far from you, come take a look at it this weekend if you got the time and inclination to do so. I will buy you lunch and an 18 pack of beer. You gotta let me help you drink it though!!! :cry:

Sure, I can helpa you out! Seems like I like fixin stuff as much as riding.....almost :cry:

I'll pm my info to ya :cry:

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well the one thing you need to ck is make sure the ft plate on the slide is installed correctly------i cant tell you how many guys put them in upside down-------it can be corrected on the bike,-------when you take it out make sure the squair end in down not the pointed end --------this is more than likely the problem !!!

Kelstr makes a great point. But Id assume the shop knows, but then again :cry:

Its so easy to f that up... :cry:

Id know that sound 200 yard away though...so would the rest of the neighborhood :cry:

When I did that on my YZF, it was blowing flames out the muffler 2 feet long!

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I was in a hurry once and did exactly that...carb slide plate upside down. Don't assume the dealer got it right.

Check it...sure sounds like a good possibility.

Although when mine was in upside down it would barely start...

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Thanks for all the help guys. The quickest way to make sure that it is the carb is to use my buddy's. I will go get his at lunch today and swap it after work. If the popping stops, I will start going through my carb.

I will first check the slide, maybe the dealership dude messed up. Then, I will remove the fuel screw and clean the cicuit. Maybe the mechanic did not actually remove the screw when he sprayed out the circuit. We'll see. Finally, i will take the entire carb apart and soak it then clean it with the ultrasound clean between teeth cleaning thingy. :cry: If that does not work, I give up and will take up another sport, like hop-scotch.....NOT!!!!!!!!!!!!!!!!

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Although when mine was in upside down it would barely start...

Been there, done that....right after a top end rebuild. I thought I screwed something up big time. Boy was I relieved when I flipped the plate around and it fired right up.

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Although when mine was in upside down it would barely start...

Been there, done that....right after a top end rebuild. I thought I screwed something up big time. Boy was I relieved when I flipped the plate around and it fired right up.

Hahaha, same thing I did, it was just too long between removing it and putting it back together...funny though, it LOOKS like it SHOULD go in the backwards way...if you think like a 2 stroker would...hahah...live and learn.

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Dealer did in fact install the slide in upside down. The hole was at the top. Just to be 100% sure, the "M" that is on the slide should be right side up when installed properly, correct?

Thanks for all the help guys. I now ride again!!! :cry:

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