Bolt-On Power

Carb and Pipes

The first thing we had to do was to get a baseline dyno run with the stock parts. The numbers were 56 hp and 70.9 lb-ft of torque. Not bad, but we knew it could be better.

After letting the bike cool down, Truesdale removed the air cover cleaner and filter to get to the carb.

He loosened the throttle cables, then removed the fuel line and the vent line.

With the stock carb off, he showed us some of the things that were done to the Wally carb. The stock slide was rough and had burs on it, and it was now 24 grams heavier than the reworked carb.

The first thing that we saw on the Wally carb was that the slide was polished and beveled, and the air hole was drilled out one size bigger, so it opens faster.

The bore of the carb was also polished smooth and widened, so that air moves through it quicker

All of the re-worked carbs get jetted, and this is the time when Kerstetteer asks what size you want installed. We told him what we had and this was his recommendation for the stock Road King. He always marks the bottom so that you have a reference point.

One thing we need to point out -- all Kerstetteer carbs have had the factory plug drilled out for the idle mixture adjuster. Although H-D carburetors are set and should be fine, this is one more thing that may need to be adjusted after the install and would be a pain with it back on the bike.

This may be hard to see, but both the needle jet and the main air jet were replaced with larger sizes.

Next, he installed the carburetor and connected the fuel lines and the cables.

After he turned the gas on, we found that the inlet fitting was cracked and needed to be replaced. We got lucky; Truesdale had a new brass fitting in his toolbox. He said that this happens all the time with the plastic fitting.

With everything bolted back up, he showed us how to lube the cables so that the throttle moves smooth and removes any dirt. The tool clamps around the cable sleeve and seals one end, and with some WD-40 sprayed down into the cable, it will flow all the way through.

Now Truesdale did the next dyno run. The bike had a gain of 1 hp and 2 lb-ft of torque -- not bad for the amount of work that was done at this point. The thing we noticed was just how smooth the carburetor felt; there was no drag, hesitation, or burping.

The next thing was to install the exhaust. Truesdale laid out a set of Big Mouth mufflers with a polished stainless steel finish.

After the bike cooled down, he removed the saddlebags and the stock mufflers. The clamps would need to be reused, so he removed the bolt and added some threadlocker to the clamp bolt.

Now the clamp would slip over the new muffler. He left it just a little loose until he could bolt up the support bracket under the saddlebags.

The mufflers slipped on with very little effort, then all he had to do was line up the bolts and the support brackets. With a drop of threadlocker, they were tightened.

With some stainless steel cleaner, the muffler was wiped down to remove all the fingerprints and any thing on the pipes that would stain them.

On the last dyno run of the day, the numbers were 64.7 hp and 76.7 lb-ft of torque. Pretty impressive for a set of slip-on mufflers and about two hours of work. Truesdale was sure with a little more time on tuning and a better-than-stock air filter, the Road King would do 10-plus hp.

If you are looking for a low-cost way to get something extra from your stock bagger, we have found one option that can do the trick. We have a stock -- and we mean a bone stock -- Road King on hand, and you know what they say about stock. So, we were looking for a low-cost way to get that little extra something, and we came across Wally Kerstetteer in Sunbury, Pennsylvania, who reworks stock Harley-Davidson CV carburetors for better throttle response and to eliminate carb burping on heavy acceleration.

Kerstetteer cleans and polishes all the moving parts of the carb, then drills all the air holes in the slide to be bigger. He also raises the float, bevels and reshapes the slide to lighten it up, as well as re-jets and adjusts the spring tension. For just over $100, he has all this and more done to the carb and shipped back in just over a week. When you get it back, you will think it is a new carb.

Then, to get all that we could from this bike, we heard that Joker Machine now makes exhaust systems for big twins. It has a set called Big Mouth Mufflers that on the average will give a 6-8hp gain from just slipping them on. We decided to stop by and ask if they would help us out of this stock bike rut we were in. Brian Truesdale, Joker Machine's R&D; guy, was glad to show us how well the mufflers work, so wasting no time, we got to work.