In the last installment, I had removed this set of carburetors from a 97 Honda Shadow 1100, after washing all of the loose crud from the exterior it was time to begin dis-assembly. This is not going to be a full on complete step by step tutorial, but we will cover all of the highlights that are specific to this job. Here you can see that the float bowl is off and although the interior of this carb does not look that bad there is a thin film of of fuel varnish on all the surfaces so I definitely going to clean that out.
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As always when working with multiple carburetors, it is best to dis-assemble one at the time and to lay the parts out in a reasonably orderly fashion so that you can reinstall the parts back into the carb body that you removed them from. Below you can see the float bowl, float, jets, etc. are lying on the table and I’ve removed the top and am about to pull out the spring and slide.
Since my ultrasonic cleaner is small to prevent part mix ups I only put one carbs parts at the time in it. One nice thing about dealing with the Shadow carburetors is that both of the air cut off diaphragms are on the outside of both carb bodies and can be reached without breaking the carbs apart, this makes it much easier to clean those critical passages.
Now it’s time to begin the modifications that will really wake your old Honda up and make it sing a new song of power and glory! You should wash the slides off good and inspect the diaphragms for holes, or rips, if you find any problems you will need to replace the diaphragm before proceeding but if all is well, look insde at the retainer and using either a proper JIS screwdriver or an 8mm socket twist the retainer counter clockwise about 1/4 of a turn until it pops loose and will fall out, remove the needle (aka the metering rod) being sure to note if there damage to the retainer or it’s spring.
The Dynojet Research needles are packaged as shown, refer to the instructions in your jet kit for assembly instructions to match your particular application.
Here’s a quick shot of the slide, retainer & jet needle.
The next picture down is a comparison of the shape of the stock needle to a Dynojet needle. This difference in shape makes enough of a difference in flow that it should be used with the matching jets supplied in the kit. Likewise you can’t use your leftover kit jets in another bike without purchasing the correct needles.
The stock Honda needle is on top and the Dynojet needle is below it.
To simplify reinstalling the needle first insert it along with any spacers into the slide, then place the retainer into the end of an 8mm socket like this and then turn the slide upside down
while holding onto the needle as shown in the following picture andinsert the retainer into place and turning it to the locked position.
Before I finish cleaning the bodies the idle mixture screws need to be removed. They are located under these caps on the sides of the carburetors. If you live in a state that requires visual emissions equipment inspection you should purchase new caps when you buy your carb kits or your bike will fail inspection if it does not have these caps on it.
Centerpunch the holes and the very carefully drill through the caps stopping as soon as the drill bit breaks through the caps so you do not damage your carbs.
Then you a sheet metal screw of the right size (supplied in the Dynojet kit as is the drill bit) and screw it into the hole far enough to get a good grip on it & then
yank it out with a pair of pliers. If you are just installing the jet kit without cleaning the carburetor turn the screws all the way in until seated and then back out 3 turns for your initial setting. If your are cleaning the carbs as I am here carefully remove the mixture screws, their springs, washers and o-rings and then thoroughly clean the carb bodies.
In this shot below things are going back together now, just reverse the diss-assembly process checking all of your parts,float height, gaskets etc. and correcting any problems you find.
When it is time to put in the main jet you have a decision to make based upon the modification level of your motorcycle. Since this particular bike had a pair of large tube drag pipes on it, I went ahead & put the largest jets in the kit in it. Don’t just automatically put the biggest jets in especially if you are running stock or quite aftermarket pipes and the factory air filter setup.
You should also be prepared to do a bit of tweaking especially to the idle mixture screws to get a good idle with a good throttle response as you come off idle. One must also be prepared if necessary to pull the carburetors completely back out if need be to try a different set of jets or alter the jet needle cir-clip position for the best running. If you pay attention to the instructions in the kit this is not likely but it is a possibility.
There you have it, if you’re contemplating doing this to your bike at home first make sure that it is running well, and that it has new plugs, and that the ignition and charging systems are up to spec, and that there are no other problems such as cracked intake boots that would cause you to have drivability issues. If you put a jet kit in a motorcycle that is not running right to start with, you are very likely to have a motorcycle with a jet kit in it that still does not run right.
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Just take your time, read the directions, and keep everything as clean as possible and you should be able to make your old Shadow run & sound even better than it does now.