Hey guys i'm new here and am in desperate need of some expertise. I have a 98 300 4x4 that will not idle with the choke off. It runs like a dream on half choke, it will run up and down the road on half choke and with the choke off, but won't idle at all without choking it. When you turn the choke off its as if you hit the kill switch. I have taken the carb apart 3 times and cleaned it the best I know how. I'm no mechanic so it's possible I could have missed something. I was wondering could there possibly be something wrong with the choke? Thanks in advance for your help. FYI I let the bike set up for over a year.
Rebel36
Welcome to the forum. There are free downloadable manuals on here, somewhere, I forget where exactly, lol.
I'm guessing the air cleaner is clean, carb boot clamps, all vent lines clamped and unclogged?
It sounds to me like you have a vacuum leak or wrong air/fuel adjustment. I would recommend double checking the carb, and resetting the mixture to factory spec per the manual. (remember 1 turn is a full 360, some folks only go 180, easy to mistake when your going quick) Also might try bumping up the idle some. That should be a good starting point...
I'm guessing the air cleaner is clean, carb boot clamps, all vent lines clamped and unclogged?
It sounds to me like you have a vacuum leak or wrong air/fuel adjustment. I would recommend double checking the carb, and resetting the mixture to factory spec per the manual. (remember 1 turn is a full 360, some folks only go 180, easy to mistake when your going quick) Also might try bumping up the idle some. That should be a good starting point...
Welcome to the forums. My guess is that you've still got some dirt or debris in the pilot circuit of the carb. When you cleaned the carb, did you remove the all the jets and clean them, so that you could hold them up to light and see through them? Also, did you remove the pilot screw and spray carb cleaner in all the passageways in the carb body and blow them out with compressed air?
Thanks Dan
I only know of the one vent line that runs under the tank to the handle bars, and it's clear. Clamps are all tight and I don't really know much about the air or gas adjustments on the carb. I just can't understand why it just dies the instant you take the choke off. Again i'm not a mechanic so do be afraid to treat me like an idiot.
I only know of the one vent line that runs under the tank to the handle bars, and it's clear. Clamps are all tight and I don't really know much about the air or gas adjustments on the carb. I just can't understand why it just dies the instant you take the choke off. Again i'm not a mechanic so do be afraid to treat me like an idiot.
The pilot screw is located in front of the carb bowl and screws up into the bottom of the carb. Before you take it out, screw it all the way in until it's lightly seated, while counting the number of turns it takes. Remember how many turns it takes so you can put it back where it was when you reinstall it. Be careful that you don't loose the tiny o-ring, spring, and washer when you take it out.
Here's a brief writeup of how I clean a carb.
First, you need to take the carb off. Next, remove the bowl and remove the float and float valve. Now, remove all the jets and clean them and make sure the hole in the jets isn't clogged up. Hold them up to light and make sure you can see through them. If they're clogged up, use a piece of wire from a wire brush, the wire from the inside of a trash bag tie, a small sewing needle, or just anything small enough than you can poke through the jet and remove the clog. Don't use anything big enough to damage or wallow out the holes in the jets. Soaking them in carb clean will help if you have a hard time unclogging them.
Now, turn the pilot screw all the way in while counting the number of turns it takes to turn it in. Remember that number because you will need it to be able to put the pilot screw back to where it was. Just turn it in until it stops. Don't tighten it or you will damage the end of the screw. Now, remove the screw completely. There will be a spring, washer, and tiny o-ring on the screw, so don't lose them. The washer and/or the o-ring will probably stay down in the hole and you will need to dig them out with a tiny screwdriver or pick. While the pilot screw and all the jets are out, spray carb cleaner and blow air through all the passageways in the carb body, especially the ones that the slow jet and pilot screw go in. Don't forget to blow air through the fuel inlet to the carb bowl and out the hole where the float needle goes.
Next, clean the inside of the carb and the carb bowl with carb cleaner and remove any buildup in the bottom of the carb bowl. Get the cleaned pilot screw and put the spring, washer, and tiny o-ring on in that order. The washer goes next to the o-ring, not next to the screw head. Be careful that the o-ring goes into the hole straight and square and put the pilot screw in and tighten it all the way in to the lightly seated position. Remember, don't over tighten or you will damage the end of the screw. Now, back the screw out the same number of turns that you counted when you turned it in earlier. Check the end of the float needle for damage and also check the hole where the needle seats for any damage or dirt buildup. Reinstall all the jets and reinstall the float and float needle and put the bowl back on. Reinstall the carb.
If the carb was real dirty and the passageways were stopped up in the carb body and you couldn't get them unclogged by spraying carb cleaner in them and blowing air through them, then you will need to soak the carb in carb cleaner. You can buy one gallon buckets of carb cleaner from the auto parts store with a basket to hold the carb. Make sure you remove any rubber parts, such as o-rings before spraying carb cleaner or soaking the carb in carb cleaner. The carb cleaner will melt the rubber parts.
Also, see Shadetree's thread on cleaning carbs.
http://www.hondaatvforums.net/forums/repair-maintenance/11134-how-clean-carb.html
Here's a brief writeup of how I clean a carb.
First, you need to take the carb off. Next, remove the bowl and remove the float and float valve. Now, remove all the jets and clean them and make sure the hole in the jets isn't clogged up. Hold them up to light and make sure you can see through them. If they're clogged up, use a piece of wire from a wire brush, the wire from the inside of a trash bag tie, a small sewing needle, or just anything small enough than you can poke through the jet and remove the clog. Don't use anything big enough to damage or wallow out the holes in the jets. Soaking them in carb clean will help if you have a hard time unclogging them.
Now, turn the pilot screw all the way in while counting the number of turns it takes to turn it in. Remember that number because you will need it to be able to put the pilot screw back to where it was. Just turn it in until it stops. Don't tighten it or you will damage the end of the screw. Now, remove the screw completely. There will be a spring, washer, and tiny o-ring on the screw, so don't lose them. The washer and/or the o-ring will probably stay down in the hole and you will need to dig them out with a tiny screwdriver or pick. While the pilot screw and all the jets are out, spray carb cleaner and blow air through all the passageways in the carb body, especially the ones that the slow jet and pilot screw go in. Don't forget to blow air through the fuel inlet to the carb bowl and out the hole where the float needle goes.
Next, clean the inside of the carb and the carb bowl with carb cleaner and remove any buildup in the bottom of the carb bowl. Get the cleaned pilot screw and put the spring, washer, and tiny o-ring on in that order. The washer goes next to the o-ring, not next to the screw head. Be careful that the o-ring goes into the hole straight and square and put the pilot screw in and tighten it all the way in to the lightly seated position. Remember, don't over tighten or you will damage the end of the screw. Now, back the screw out the same number of turns that you counted when you turned it in earlier. Check the end of the float needle for damage and also check the hole where the needle seats for any damage or dirt buildup. Reinstall all the jets and reinstall the float and float needle and put the bowl back on. Reinstall the carb.
If the carb was real dirty and the passageways were stopped up in the carb body and you couldn't get them unclogged by spraying carb cleaner in them and blowing air through them, then you will need to soak the carb in carb cleaner. You can buy one gallon buckets of carb cleaner from the auto parts store with a basket to hold the carb. Make sure you remove any rubber parts, such as o-rings before spraying carb cleaner or soaking the carb in carb cleaner. The carb cleaner will melt the rubber parts.
Also, see Shadetree's thread on cleaning carbs.
http://www.hondaatvforums.net/forums/repair-maintenance/11134-how-clean-carb.html
In case someone else has this same problem and is interested in the outcome of this thread, see the link below.
http://www.hondaatvforums.net/forums/honda-trx/13663-thanks-helmut-shadetree.html
http://www.hondaatvforums.net/forums/honda-trx/13663-thanks-helmut-shadetree.html
Welcome to the forums...Free downloadable manuals in the Schematics/Manual help section in the Technical discussions ...
Might have a piece of dirt in the idle jet of the carb. I recommend you start a new thread—give brief model info and describe your skill level. If you’re not confident about your ability to clean or rebuild the carb you could have the Honda shop do it—meet some new friends that way. About $275 for rebuild.
Download the service manual and click my parts links in my signature block below
Always buy OEM parts
Download the service manual and click my parts links in my signature block below
Always buy OEM parts
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