Carb Disassembly Tips
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edzinohio wrote:
I can't stress enough that you need to be sure that everything is super clean. Think everything through and take your time. Be sure to set the float heights EXACTLY to factory specs - I'm talking all within 1/2mm of each-other.
Even though the Clymer manual might have some good tips, the factory manual hasfar fewermistakes. When it comes to things like jet sizes, use the factory manual.
Carbs are fairly simple, but working onthem is like working on a fine watch. All those tiny passages, emulsion tubes, and jets are critical to your bike running right. Do it right the first time by being well-organized, working in a clean andwell-lit area, and taking your time to think things through.
When cleaning out the carbs, use carb cleaner, pipe cleaners,a toothbrush,and whatever else might work followed bycompressed air to blow out the passages. Don't use wire to clean out jets unless it's specifically designed for the purpose- you could end up enlarging them!
While you're at it, be sure your gas tank is not full of rust or other junk, and install a new fuel filter. It would be a shame to gunk up your newly rebuilt carbs with crap from a dirty or rusty gas tank.
edzinohio wrote:
It will be a lot less trouble if you don't split the plenum... leave the carbs attached to the plenum andonly take the tops and bottoms off to clean/rebuild them.
I can't stress enough that you need to be sure that everything is super clean. Think everything through and take your time. Be sure to set the float heights EXACTLY to factory specs - I'm talking all within 1/2mm of each-other.
Even though the Clymer manual might have some good tips, the factory manual hasfar fewermistakes. When it comes to things like jet sizes, use the factory manual.
Carbs are fairly simple, but working onthem is like working on a fine watch. All those tiny passages, emulsion tubes, and jets are critical to your bike running right. Do it right the first time by being well-organized, working in a clean andwell-lit area, and taking your time to think things through.
When cleaning out the carbs, use carb cleaner, pipe cleaners,a toothbrush,and whatever else might work followed bycompressed air to blow out the passages. Don't use wire to clean out jets unless it's specifically designed for the purpose- you could end up enlarging them!
While you're at it, be sure your gas tank is not full of rust or other junk, and install a new fuel filter. It would be a shame to gunk up your newly rebuilt carbs with crap from a dirty or rusty gas tank.
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You'll have to split the carbs from the plenum, the air cutoff valves are on the side of the carbs, and 2 of them are right up against the carb next to it.
Raymond
You'll have to split the carbs from the plenum, the air cutoff valves are on the side of the carbs, and 2 of them are right up against the carb next to it.
Raymond
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An important element is to clean the idle mixture jet thoroughly. This is one that you can't remove it is the middle riser of the 3 that protrude into the float bowl. Its right next to the main jet riser.
I prefer to soak carbs in an ultrasonic cleaner. This assures that the solvent makes it into all the small galleries in the body of the carb. I have rebuilt two sets of carbs.
One test to see if the idle mixture jet is clear is to turn the carb upside down and fill the cavity just above the jet with gumout. If it doesn't drain or drains very slowly it is still clogged. You can use a copper wire but nothing harder than that or you'll damage the jet. On one I had to use PB Blaster, Gumout and compressed air until I could see vapor shooting out of the pilot screw hole. Blast Gumout into the pilot screw hole and alternate with air. Stick your finger inside the carb and feel for air coming through the separate holes on each side of the throttle plate.
Gas can turn into the hardest varnish that can defy some passive cleaning methods. Your friend is the red tube that sticks out of the Gumout valve. Stick it where the sun don't shine and don't be shy. Oh and wear eye protection. Gum out can exit at unexpected locations.
An important element is to clean the idle mixture jet thoroughly. This is one that you can't remove it is the middle riser of the 3 that protrude into the float bowl. Its right next to the main jet riser.
I prefer to soak carbs in an ultrasonic cleaner. This assures that the solvent makes it into all the small galleries in the body of the carb. I have rebuilt two sets of carbs.
One test to see if the idle mixture jet is clear is to turn the carb upside down and fill the cavity just above the jet with gumout. If it doesn't drain or drains very slowly it is still clogged. You can use a copper wire but nothing harder than that or you'll damage the jet. On one I had to use PB Blaster, Gumout and compressed air until I could see vapor shooting out of the pilot screw hole. Blast Gumout into the pilot screw hole and alternate with air. Stick your finger inside the carb and feel for air coming through the separate holes on each side of the throttle plate.
Gas can turn into the hardest varnish that can defy some passive cleaning methods. Your friend is the red tube that sticks out of the Gumout valve. Stick it where the sun don't shine and don't be shy. Oh and wear eye protection. Gum out can exit at unexpected locations.
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My friend and I rebuilt my carbs on my 83 Aspencade. It ran better but still not right. I then took it to my mechanic and he went through them again. Two of the things I noticed was that heground off the stops for the jets on the bottom to give more adjustment and he made up a special needle air nozzle to attach to his air compressor. It allowed him to get into the real fine holes with compress air.
You didn't mention it but to remove the carbs from the bike is tricky. They're removed from the left side and I understand if you unbolt the front mounts it's easier to get out.
Jerry
My friend and I rebuilt my carbs on my 83 Aspencade. It ran better but still not right. I then took it to my mechanic and he went through them again. Two of the things I noticed was that heground off the stops for the jets on the bottom to give more adjustment and he made up a special needle air nozzle to attach to his air compressor. It allowed him to get into the real fine holes with compress air.
You didn't mention it but to remove the carbs from the bike is tricky. They're removed from the left side and I understand if you unbolt the front mounts it's easier to get out.
Jerry
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The way CI (RIP) says to do it worked like a champ for me. Take the downdraft tubes completely off, and remove the cables. Shove the whole assembly to the right and remove the 2 right side vacuum chamber caps, and then the whole assembly slides out the left. Makes it a lot easier to manuever and remove when the 2 right side tops and vacuum sliders are out of the way.
Raymond
The way CI (RIP) says to do it worked like a champ for me. Take the downdraft tubes completely off, and remove the cables. Shove the whole assembly to the right and remove the 2 right side vacuum chamber caps, and then the whole assembly slides out the left. Makes it a lot easier to manuever and remove when the 2 right side tops and vacuum sliders are out of the way.
Raymond
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Jerryk wrote:
Jerryk wrote:
Kind think the grinding of the stops was unnecessary, the bike's been running for 22 years with the stops on it. If it was necessary to grind them off to get sufficient adjustment, it probably something else is off a bit.
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One thing that is real important is to be sure you extract the washer and o-ring from the idle mixture screw seat. When you look down in there you will see metal all the way down to the end and a teensy bit of daylight. What your actually staring at is the bottom of the washer that is glued against the oring. That is unless you are lucky to retrieve it with the screw. Out of the 8 I rebuilt this was a recuring issue. I actually installed the screw with two orings and washers until one I was working on, I noticed had an obstruction. Got in there with the help of some dental tools and pulled those rascals out. If you spray n pray they may stay. Soaking makes them break loose. If you leave them in place they will space the screw further out and will completely screw up the mixture configuration.
The idle mixture circuit is very important not only for the idle portion of the band but is also a transitional blender to the main jet to assure smooth roll out.
Harbor Freight sells a blow gun with hyperdermic needles that you can screw on that get into the tight places.
One thing that is real important is to be sure you extract the washer and o-ring from the idle mixture screw seat. When you look down in there you will see metal all the way down to the end and a teensy bit of daylight. What your actually staring at is the bottom of the washer that is glued against the oring. That is unless you are lucky to retrieve it with the screw. Out of the 8 I rebuilt this was a recuring issue. I actually installed the screw with two orings and washers until one I was working on, I noticed had an obstruction. Got in there with the help of some dental tools and pulled those rascals out. If you spray n pray they may stay. Soaking makes them break loose. If you leave them in place they will space the screw further out and will completely screw up the mixture configuration.
The idle mixture circuit is very important not only for the idle portion of the band but is also a transitional blender to the main jet to assure smooth roll out.
Harbor Freight sells a blow gun with hyperdermic needles that you can screw on that get into the tight places.
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I am not seperating my carbs after all. I got creative with some vice grips and got the 2 inside air cut valves replaced with everything together. I got through with the rebuild kits except for the one carb where the idle jet screw got broke off. I am just going to leave it as is since that cylinder seems to idle OK as is.
Now is is almost time to put it back to gether and see if it idles right this time.
I am not seperating my carbs after all. I got creative with some vice grips and got the 2 inside air cut valves replaced with everything together. I got through with the rebuild kits except for the one carb where the idle jet screw got broke off. I am just going to leave it as is since that cylinder seems to idle OK as is.
Now is is almost time to put it back to gether and see if it idles right this time.
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