How to Set Up the Carburetor - Need help ASAP - Page 2 - Honda Foreman Forums : Rubicon, Rincon, Rancher and Recon Forum

jode · 07-22-2009, 05:16 PM

OK, so I now have it to the point where it will run. The fuel lines all checked out and I bled some air out of them to make sure they were not a problem. I also hooked a tube up to the carb and blew into it to make sure that there was a good passage-way for the gas - there is. So it is running now, but not really good. Here is what it does:

It idles just about right, but once every 10 seconds or so, it misses and you can hear the slack come out of one of the rods in the engine (a little "tink" sound)
If you hit the throttle hard, it revs up good, but backfires just a hair on the way back down (not a full backfire) but usually, it won't come back down to idle speed - it comes down to 2 or 3 times as high as idle speed. In order to get it down to idle speed, I have to just give the throttle a little "blip" and then it comes down to idle speed where it continues to run, but misses occasionally.

One thing of note here - the o-ring on the air/fuel mixture screw is actually broken. I did just throw it back in there with the break in it and I figured it would work fine that way, but maybe I was wrong? Any other thoughts?

**toodeep** · 07-22-2009, 05:29 PM

Did you end up soaking this carb in a carb cleaner (I always called it to cook/boil out the carb) or was it just sprayed out with carb cleaner in an aerosol can? There might just be enough varnish left in the passages of the carb to be messing with you.

jode · 07-22-2009, 05:34 PM

I did soak it in B12 from a 1 gallon can for about an hour and then I blew out all the passages with compressed air. I looked through all the pieces I could to make sure I could see light coming through the other side. I thought I had it pretty well cleaned out.

nocturnal396 · 08-03-2009, 11:46 AM

I've been having almost exactly the same problem. After thorough carb cleaning I have gotten to the point where it idles on it's own and drives fine but has the slight miss and some valve noise as you described at idle, revs up nice but pops a lot on the way down again as you described.

A few things I have been thinking may be causing it are incorrect float levels, need of a valve adjustment or air/fuel screw not set right.

I don't know if this is right, but a friend of mine told me that the best way to adjust the air/fuel screw is to set the idle speed screw to your desired idle RPM, then adjust the air/fuel screw till the idle raises and you get it to the fastest idle possible. When the idle is at the fastest RPM, bring down your idle speed screw back to your desired idle and the air/fuel screw is then adjusted right. Don't know if this is true or not but im going to give it a try. I'm also going to check all the grounds on my bike, clean em off, clean the contacts on the coil ect... as there is a lot of dirt and corrosion. I ordered a remanned carb for 50 bucks, so after all this is done and the new carb is on...if i still have the problem im moving to the valves. Figured i'd share as it seems like our bikes may have the same issue.

jode · 08-03-2009, 12:13 PM

Just a little update on the problems I was having:

1: I now have the carb adjusted at 1.5 turns out and it runs fairly OK
2: I had to shave down the brass throttle ramp thingy that rests on the idle speed screw. I think the erratic fast, then slow idle problems were caused by the fact that the idle screw had worn a groove into the brass throttle ramp thingy so that it wasn't always coming to rest in the same spot on the idle screw. I used a file to smooth it out again and it seems to have helped.

It now idles OK sometimes and sometimes not and it still backfire-gurgles on the way down. I am at about the same point where I think it has to be either air/fuel mixture or valve adjustment or both. Is there someone who can post the valve adjustment procedure and specs from a FSM?

On a separate note, mine is also having this problem where it seems to build up pressure in the carburetor when it gets real hot. I'll be riding around for 1/2 hour then it will suddenly just not have any fuel. It seems like the air pressure in the fuel line stops the gas from coming down the gas line into the carb bowl (and I can see bubbles coming up out of the carb up the gas line. If I open the line and let the pressure out, then it will go again. It is a really weird symptom that I may be misdiagnosing. Maybe I am just still getting limited flow through the in-tank gas filter, but how can I replace that? Do I have to buy a complete new fuel/reserve valve?

Kipes · 08-04-2009, 10:41 AM

Hey jode can you take the petcock off the tank? If so just spray it and blow it out with air and if I remember correctly there is a screen in that petcock that can get plugged up. I have had to poke a wire into them before and break the screen to get proper gas flow but if you do that make sure you put a filter inline to take its place. As for valve adjustment, I never did a Recon but it shouldnt be much different than any other Honda, biggest thing is getting to the valve cover and removing the threaded caps for the valve adjustment holes. On a couple of years they didnt put the threaded caps on and you had to remove the valve cover which is no big deal (4 bolts). I dont know what setup is in the Recon. You can look at the valve adjustment procedure in the Foreman section just to get an idea whats all involved. Most Hondas are .006 +-.001 so I usually set them at .005 ON A COLD ENGINE. And also you must have the piston at top dead center on the ignition stroke. Some guys use a screw driver in the spark plug hole and turn the motor over to find it or there should be a plug on the side of the motor you can take out and turn the motor over until you can see a "T" on the flywheel. Hope this info helps you get it back on the trail. Good luck.

Kipes · 08-04-2009, 10:50 AM

Sorry jode it was in the how-to section here
http://www.hondaforeman.com/index.php?showtopic=2663

08-04-2009, 10:41 AM	#16 (permalink)
Kipes Honda Red Wing Rider Join Date: May 2009 Location: Upper Peninsula of Michigan Posts: 2,597	Hey jode can you take the petcock off the tank? If so just spray it and blow it out with air and if I remember correctly there is a screen in that petcock that can get plugged up. I have had to poke a wire into them before and break the screen to get proper gas flow but if you do that make sure you put a filter inline to take its place. As for valve adjustment, I never did a Recon but it shouldnt be much different than any other Honda, biggest thing is getting to the valve cover and removing the threaded caps for the valve adjustment holes. On a couple of years they didnt put the threaded caps on and you had to remove the valve cover which is no big deal (4 bolts). I dont know what setup is in the Recon. You can look at the valve adjustment procedure in the Foreman section just to get an idea whats all involved. Most Hondas are .006 +-.001 so I usually set them at .005 ON A COLD ENGINE. And also you must have the piston at top dead center on the ignition stroke. Some guys use a screw driver in the spark plug hole and turn the motor over to find it or there should be a plug on the side of the motor you can take out and turn the motor over until you can see a "T" on the flywheel. Hope this info helps you get it back on the trail. Good luck. __________________ 2006 Foreman 4x4 500s Powermadd handguards 2.5 Warn winch 2" Perfex long travel lift kit High Lifter springs 26-12-12 Executioners on rear 26-10-12 Executioners on front Douglas Rattlesnake rims 3rd Headlight switch Moose Heated Handgrips and thumb warmer Garmin Legend gps Replaced the stock silver engine covers and front skid plate with 07 camo black and painted front brush guard black 2005 Rancher 350ES 2wd 2001 Polaris 325 Trailboss 2wd

08-04-2009, 10:50 AM	#17 (permalink)
Kipes Honda Red Wing Rider Join Date: May 2009 Location: Upper Peninsula of Michigan Posts: 2,597	Sorry jode it was in the how-to section here http://www.hondaforeman.com/index.php?showtopic=2663 __________________ 2006 Foreman 4x4 500s Powermadd handguards 2.5 Warn winch 2" Perfex long travel lift kit High Lifter springs 26-12-12 Executioners on rear 26-10-12 Executioners on front Douglas Rattlesnake rims 3rd Headlight switch Moose Heated Handgrips and thumb warmer Garmin Legend gps Replaced the stock silver engine covers and front skid plate with 07 camo black and painted front brush guard black 2005 Rancher 350ES 2wd 2001 Polaris 325 Trailboss 2wd

07-22-2009, 05:16 PM	#11 (permalink)
jode Honda Rider Join Date: Jul 2009 Posts: 18	OK, so I now have it to the point where it will run. The fuel lines all checked out and I bled some air out of them to make sure they were not a problem. I also hooked a tube up to the carb and blew into it to make sure that there was a good passage-way for the gas - there is. So it is running now, but not really good. Here is what it does: It idles just about right, but once every 10 seconds or so, it misses and you can hear the slack come out of one of the rods in the engine (a little "tink" sound) If you hit the throttle hard, it revs up good, but backfires just a hair on the way back down (not a full backfire) but usually, it won't come back down to idle speed - it comes down to 2 or 3 times as high as idle speed. In order to get it down to idle speed, I have to just give the throttle a little "blip" and then it comes down to idle speed where it continues to run, but misses occasionally. One thing of note here - the o-ring on the air/fuel mixture screw is actually broken. I did just throw it back in there with the break in it and I figured it would work fine that way, but maybe I was wrong? Any other thoughts?

07-22-2009, 05:29 PM	#12 (permalink)
toodeep Administrator Join Date: Aug 2007 Location: south dakota Posts: 6,653	Did you end up soaking this carb in a carb cleaner (I always called it to cook/boil out the carb) or was it just sprayed out with carb cleaner in an aerosol can? There might just be enough varnish left in the passages of the carb to be messing with you.

07-22-2009, 05:34 PM	#13 (permalink)
jode Honda Rider Join Date: Jul 2009 Posts: 18	I did soak it in B12 from a 1 gallon can for about an hour and then I blew out all the passages with compressed air. I looked through all the pieces I could to make sure I could see light coming through the other side. I thought I had it pretty well cleaned out.

08-03-2009, 11:46 AM	#14 (permalink)
nocturnal396 Honda Rider Join Date: Jul 2009 Posts: 10	I've been having almost exactly the same problem. After thorough carb cleaning I have gotten to the point where it idles on it's own and drives fine but has the slight miss and some valve noise as you described at idle, revs up nice but pops a lot on the way down again as you described. A few things I have been thinking may be causing it are incorrect float levels, need of a valve adjustment or air/fuel screw not set right. I don't know if this is right, but a friend of mine told me that the best way to adjust the air/fuel screw is to set the idle speed screw to your desired idle RPM, then adjust the air/fuel screw till the idle raises and you get it to the fastest idle possible. When the idle is at the fastest RPM, bring down your idle speed screw back to your desired idle and the air/fuel screw is then adjusted right. Don't know if this is true or not but im going to give it a try. I'm also going to check all the grounds on my bike, clean em off, clean the contacts on the coil ect... as there is a lot of dirt and corrosion. I ordered a remanned carb for 50 bucks, so after all this is done and the new carb is on...if i still have the problem im moving to the valves. Figured i'd share as it seems like our bikes may have the same issue.

08-03-2009, 12:13 PM	#15 (permalink)
jode Honda Rider Join Date: Jul 2009 Posts: 18	Just a little update on the problems I was having: 1: I now have the carb adjusted at 1.5 turns out and it runs fairly OK 2: I had to shave down the brass throttle ramp thingy that rests on the idle speed screw. I think the erratic fast, then slow idle problems were caused by the fact that the idle screw had worn a groove into the brass throttle ramp thingy so that it wasn't always coming to rest in the same spot on the idle screw. I used a file to smooth it out again and it seems to have helped. It now idles OK sometimes and sometimes not and it still backfire-gurgles on the way down. I am at about the same point where I think it has to be either air/fuel mixture or valve adjustment or both. Is there someone who can post the valve adjustment procedure and specs from a FSM? On a separate note, mine is also having this problem where it seems to build up pressure in the carburetor when it gets real hot. I'll be riding around for 1/2 hour then it will suddenly just not have any fuel. It seems like the air pressure in the fuel line stops the gas from coming down the gas line into the carb bowl (and I can see bubbles coming up out of the carb up the gas line. If I open the line and let the pressure out, then it will go again. It is a really weird symptom that I may be misdiagnosing. Maybe I am just still getting limited flow through the in-tank gas filter, but how can I replace that? Do I have to buy a complete new fuel/reserve valve?

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