Start-Up And Adjusting

Make sure that the kit is completely installed, with the air cleaner back on, and the choke cable installed (remember to finger tighten the cables big nut to the bracket). Turn on the petcock, and check for fuel leaks. During the carb's setup on the bench, the mixture screw should have been screwed out 2 1/2 turns, and the idle speed screw on the side should be adjusted so that the butterfly is just exposing the first of the (5) pilot transition feed holes (this should have already been setup on the work bench!). Ignition timing should have already been correctly set. See my ignition timing section here! Fully retard the left ignition timing grip, and fully pull on the choke cable. Turn on the ignition switch, and kick. It should start right up with a fast idle. Slowly advance the ignition, and simultaneously reduce the amount of choke as the motor warms up. The carb needs to have some choke for a couple of minutes until the motor is fully warmed up. This is normal for H-Ds also. With the timing retarded about half, adjust the idle speed screw for a nice idle. Trim the mixture screw first by screwing it inward (lean), until the idle speed drops some. Slowly start screwing the mixture screw out (richer) until you have reached the fastest, and smoothest idle. This procedure is needed after every idle speed screw re-adjustment. I recommend setting up a retard limiter (see my explanation here in the timing section) so that there isn't the full 39 degrees of timing from the grip. With about 20-22 degrees spread, the idle speeds at full advance, and full retard will be closer to the same. This makes for a Happier bike. When re-starting the bike when warm, always fully retard the timing, sometimes pull on a little choke, give it no throttle, and kick. You will be amazed how smooth the bike sounds!

Ignition Timing

The ignition timing issue is going to be very controversial to many people, because the results I found experimenting with timing are nowhere near the marks dictated by the factory. Since we no longer use the same fuel they used in the 1940's, and we are now using a modern efficient carb, we need to start from scratch. Long before I experimented with CV carbs, I was testing for less advance, and leaner mixture for more power, and smoother running. Several years ago while on a 1,000 mile Sierras, and Nevada cruise I started playing with timing, and mixture. I kept dialing out some advance, and trimming my high speed needle for the best seat of the pants feel, and when I returned home to measure the timing, I found that I was a little below 30 degrees full advance. The factory has different settings for various motors, and they are all above 35 degrees! The 80" motor by the book is 11/16" before TDC, which equals 40 1/2 degrees. These numbers are far too high, and will cause severe heat inducing detonation, and a loss of power. I took this recent 1951 80" with "Ollie" cams over to our local Dyno where the operator is extremely schooled in building power in H-D twins. I rode tested, and setup this bike with my best seat of the pants feel. It felt real good. I had the timing at 30 degrees, which I felt was appropriately retarded. We did 10 runs, and each time we retarded the timing a little bit. It kept getting better. When it reached the peak torque, and power, we began to lean out the main jet for maximum power. I started with a 170 Main, and ended with a 160 Main (as I predicted). The jet change only increased the power a little. The whole time, we are monitoring the air/fuel ratio to be proper, and the needle setting I chose was perfect everywhere (3rd clip from the top). I was anxious to come home, and measure the full advance timing number, and I was suprised to find it at only 13 Degrees full advance!! I don't know how this can be possible, so I called the dyno expert, and he explained that the dyno never lies, and that the motor only needed the 13 degrees to make it's power at it's state of tune. Indians have very little compression, which requires less advance, and the fine atomization from the CV carb requires less timing to fully fire the fuel. Any excess advance in a motor just results in a burn too soon where some of the power is lost on the wrong side of TDC. When this happens, extra heat builds up, causing excess wear, and hot oil. A little more advance, and you get destructive detonation. The dyno guy said that a little less timing is needed at elevation, and since we are at 7,000' elevation in Santa Fe, New Mexico, our 13 degrees might need to be bumped up to around 18 degrees at sea level. The higher air density at sea level creates more effective compression in the motor, and thus, the need for a little more advance. Only a dyno run on a particular bike will yield the correct timing number for your bike. I set this bike at 18 Degrees, so some sea level use could be done without losing our good power found with 13 degrees here at 7,000'. On my own 80" Bonneville, which I have been riding at 30 degrees advance, I bumped it down to 20 degrees, and it runs quicker, and smoother now. I am not imagining this. We found an additional 15% torque, and horsepower just by retarding the ignition, and when I rode this bike home, I could definitly feel an improvement. This bike now screams, and is making the same power as a stock H-D Evo motor! Now there is another advance issue that must be addressed. The stock Indian advance mechanism sweeps a full 39 degrees of advance from full advance to full retard. This would be fine if the factory timing marks of around 37 degrees are in fact correct, because full retard would be at around 3 degrees after TDC for idle. But with timing fully advanced at only 20 degrees, the full retard would be at 20 degrees after TDC, and the idle would be very incorrect. On our (2) bikes I made little retard limiters that fit into the curved slot to cut the amount of advance in half (only 20-22degrees). Now the idle speed is adjusted at full retard (a few degrees after TDC), and when advanced, the idle speed only comes up a little bit, but sounds great. You come up to a stop light, and fully retard the timing, and the bike idles very smoothly. Click it in gear, advance it, and take off, and it feels very nice. Again, only a full dyno test will determine your bikes perfect timing number.

Modifying the Flywheels into "Degree Wheels"

I found a handy way to turn your flywheel into a degree wheel for acurrate timing, is to stamp some marks on the flywheel through the inspection hole with a spring loaded punch, and a simple to make guage strip. Make a short sheet metal strip about 3" long, and 21/64" wide (.328) as a guage. Cut it, file it, and measure it accurately. This guages width represents 5 degrees of crank timing. Assuming the TDC mark (+) is correct, this guage can be held in place up against the TDC mark on it's right edge, and the left edge is now at 5 degrees before TDC. Carefully mark, and gently center punch this mark. Continue moving to your left making new 5 degree marks as you go, and eventually you will see the original ($) timing mark at around 37 degrees. Now paint very thin vertical lines at each 10 degree increment (TDC,10,20,30,etc.) with different colored paints (gold,red,orange,yellow), and paint thin white lines at each 5 degree increment. You will be delighted at what you will see through the clear plastic plug with your timing light.

Clear Plastic Timing Plugs can be bought from Ed Glasgow for $10.00 each. He can be reached at 1-315-696-8076.

A simple way to approximate 20 Degrees Timing

For those that don't want to get as involved with the timing marks mentioned above, there is a simpler way. Assumming that your (+) mark for TDC is near correct, and your($) full advance timing mark is near correct at 38 degrees, you can split the difference, and find 19 degrees before TDC. Look in the inspection hole for both marks, and put a new mark exactly between the two of these, and this is where the CV carb will work at its best. Simple!

Advance Bracket Timing Limiter Modification

Study the picture of a standard Chief advance bracket, and the one that I modified for half the travel. The advance cable moves this part against the sides of the special shouldered bolt that holds the advance mechanism all together. I cut-out a small piece of .100" thick steel to fit into the slotted groove on the side where retard sits, and I tack welded it in. It needs to be sanded down smooth so the mechanism will move freely as original. The curved portion on the advanced side needs to still fit nicely against the radius of the shouldered bolt, because the two pieces are in constant contact with each other the whole time you are riding. Therefore, the edge of this new piece where retard sits is rarely used, and this surface can be trimmed back after welding with a file, or Dremmel tool to achieve the .535" width to limit the advance travel to half of original, around 20 degrees.

The distributor must be removed before this part can be modified. First pull off the distributor cap, and rotate the motor around so the rotor is pointing forward (for later referance). Place an identifying mark on the distributor body, and on the advance bracket adjacent to each other so you can put the bracket back on in the same place. Remove the advance cable, and take out the shouldered bolt. Do not remove the lower clamp that is tight to the oil pump! After modifying the bracket, and re-installing it on the distributor, drop the distributor back into the oil pump with the rotor again pointing forward. This should retain your original full advance timing position. Re-time the full advance for 20 degrees.

This Mod is required for proper operation. It will run, and start without it, but you will not like how the bike idles at full retard. Just Do IT!

Recommended Jetting Specifications

As I have mentioned before, all of my research, and developement has been done using the Dyno-Jet Kit that I recommend. It is the kit for generic Harly-Davidson Big Twin Evo's which are closest to the state-of-tune of our old Chiefs. I have never, nor will I ever run one of these carbs without this kit, because the Dyno-Jet factory did the research to give back the power, and drivability to this carb that was lost while making it pass strict California emissions tests. This jet kit on the H-D's added back 24.5% more power to an Evo motor when used with a K&N Filter! I want the same increase in power, and throttle response on my bike, as I am sure you will too! The carb in it's stock form will start nice, idle great, and run well, but it won't be as good as one with the jet kit!

I have found a variety of main jet sizes, and needle shapes from one carb to another to suit the particular H-D application. The pilot jet needs to be increased from a #42 to a #45 in all cases, and the main jet should be 170-175 for sea level, and 160-165 for high elevation. The stock needles are fixed-position, but I have seen very small washers used on the needles to raise them a little to richen the needle "everywhere". Use your own discretion when playing around with stock jetting.

Otherwise, here are the preferred jetting specs using the Dyno-Jet Kit. The new diaphram spring is lighter, and allows the slide to raise quicker. The small hole on the bottom of the slide is opened up some to quicken the opening of the slide. The Dyno-Jet Kit comes with a #29 drill that is slightly too large for our application.You should use a (.125") drill bit instead. This allows for a stronger vacuum signal, and thus, quicker throttle response. The new needle has (6) adjustment slots, and we use the (3rd) from the top. A new "emulsion tube" for the needle is included, and the new jets have finer threads, so you must use Dyno-Jet main jets only. H-D jets are coarse thread, and will not fit. The main jet is 160 for high elevation, 170 for cool sea level, and 180 for hot sea level. Some guys are using the 180 for their 84" motors. Again, the pilot jet should be increased to a #45, and this does not come in the jet kit. It can be bought at any H-D Dealer. Set the mixture at 3 turns out. That's It!

Important-Read Each Catagory Below for Full Details!