1996 KTM Duke Review

1996 KTM Duke Review

Deciding on the Duke..
I was getting tired of ridding the popular rice rockets because of their ridding position weight and that fine (sewing machine like) vibration they give. I wanted something more comfortable, and with a more upright seating position. After selling my 92 Katana 750 I started looking for a dual sport that I would primarily ride on the street short distances. I looked at the current dual sports and liked the Suzuki DR 650 because of the weight, electric start, quality, and reliability associated with this bike. I didn't like the way it came stock so, I started looking at moods that would make it less dual sport looking, increase braking ability, and better tires for the street. I wanted a comfortable street contender, (in dual sport sense)or cool bike to run light groceries. All the mods I wanted like new wheels, bars, and tires were starting to add up pretty high.
On a trip to Cuba during this time, I saw some JAWA and MZ bikes that looked like what I wanted to do with the DR. With this in mind and the cost of the added mods to the new bike price, I decided to start looking for a bike that might come this way already. I saw a picture of the Duke in one of the magazines doing a wheeling and earning the magazines reward of best fun for the buck bike. Right there and then I knew the Duke would fit the bill.
Shopping for a Duke..
Duke shopping I went not knowing what it would cost or where to shop. There aren't a lot of new bike dealers in South Florida and they were saying things like, a what, Duke, who makes that. Well no Duke for me that that summer in 1996.The DR was starting to look like a better option.
In June of 97 I saw a Duke at one of the same dealers. They were now a new KTM dealer and wanted to unload a 95 model. The deal was made and the bike was taken outside. A kick start only bike was new to me since my TS-185 days for those who can remember dual sport bikes being about half of the bike out there. I didn't think I could kick start a big single cylinder with the starter lever on the left side. I also read that single four strokes were hard to start when hot.
I was going to take the bike I told them as long as I could kick-start the thing. Well, I couldn't even get it to pop, or push start it. The sales rep got it and kicked like his commission depended on it. He only started it once, and latter it flamed out (thank the Quick Silver crab for that). I went home without the bike, and disappointed. They dealer wanted to sell the bike and were pissed at me ( I would pay for that latter). My wife who witnessed the ordeal couldn't understand why a new motorcycle wouldn't start. So much for a new Duke again. I had a new baby coming and wasn't in a hurry for a new bike.
I started calling around and found a dealer who had a 96 with electric start for $7400. plus tax and tag. I told them ok, and would get it in a week or so. I got the dealer and was in a hurry to get home (4 hour drive). I had to remove the mirrors and the front fender to get it in the truck, and didn't test ride the bike. Mistake numbers one, when buying an unfamiliar make. Test ride it or go home without the bike.
It did start easy with the electric starter, and it sounded great. The bike was shiny and it looked awesome. Why would a bike from a well-known manufacturer have any problems I thought. I wrote a check and loaded the bike in an Aerostar van. With the mirrors and front fender removed it fit with plenty of room. I couldn't do that with the DR.
I latter learned that if you looked in the Motorcycle News there were plenty of ads for KTM's and I saw one Duke in a box for $6500. Live and learn. I was starting to find that you either loved the Duke, or hated it. There were plenty of KTM fans I found out by calling the ads.
New Bike in the Neighborhood...
The next day the bike started easy enough with the push of a button and was a pleasure to drive through the neighborhood. The seating position was a little high, it could take the speed bumps without a whimper and the single thump vibration was tolerable. It even had a nice sound to it. The brakes were also the best I had tried to this date. I would have never considered attempting a stoppie until that day. The lightweight of the bike helped a lot too with the handling. The looks and comments I received were too much to write. I thought to myself that I made a good choice.
A few days latter I took the bike for a good run and found it had a miss at mid throttle. It was also very hard to start. When it did start the battery was almost dead. I called the dealer to have it looked at (remember the guys who were pissed) and they said sure bring it on down we'll get to it in about a month. They also said KTM doesn't pay well for service so they can only give me about an hour worth of service for free. They also said the bike had a recall notice on the quicksilver carb, and it would take another three weeks to get it turned around.
The bikes first service call...
I was not a happy camper having spent $8000 on a bike that doesn't run right. With the help of the information operator I got a hold of KTM, wrote them a letter, threatened with the lemon law clause, and just kept complaining. They got the dealer to take the bike and correct any problems. They also said off the record that they still had some growing pains in the states.
They dealer took almost eight weeks to get the bike back to me and it ran the same. I decided to either fix the bike myself, or sell it. I had then read Randy Sneed's article on his Duke in The Thumper Page and it inspired me to get mine running despite all the comments I received from my bike buddies (are you a fool, what did you buy this for, ha, ha, ha, etc.).
On the road to fixing the Duke...
The first thing I did was get a hold of Edelbrock concerning their QuickSilver Carb. They were positive about their carb and couldn't say enough about how great it was. They said the problems I was having were related to a lean setup by KTM in order to meet California emission standards. They said to send it on down for an off road conversion and the bike would run like a champ. For an extra $14 they would even install an external needle adjuster. The charge for both was $85.00. A steal I thought for the amount I already had invested in the bike.
The carb was easy to remove once you get to working in the tight confines of the bike. As promised the carb came back ten days latter ready to bolt on. They shipped it in the same old Kraft mayonnaise box I sent it in. The carb now sported some new vent lines and the red anodized needle adjuster on top. There was no instruction about incorporating the new vent lines into the existing vent pluming. The carb was installed and the vent lines were run down to the swing arm area. Some plastic tie wraps were used to secure them.
The bike started right up and felt great. Mid and top end power were improved. The bottom end had some new punch to it too. I took the bike out for a long test ride. When I released the throttle in lower gear from high RPM the engine would backfire and a big cloud of black smoke would be left behind on the trail. That was new. So much for a bolt on carb. My ridding buddies were laughing again.
I played with the needle adjuster and got the bike running fine I thought. Every time I would let the bike sit a while it would again be hard to start and even war down the battery a few times from cranking. By now I had about 1000 miles and two oil changes. The oil changes were also expensive. About $45 after adding the oil and this doing it myself. You also had to bleed the system, which got oil on a lot of things. The main drain plug has a copper washer and a magnet to pick up metal debris. I did find some on the first change and less on the second.
I scheduled a dyno run at a local shop to see how much power the bike had. The bike would now either flood out and then start, or be too lean and not start. A new friend I met on the net, Steve who races a KTM with a Quicksilver says I was starting it wrong. I did exchange notes with other Duke and they reported the same starting trouble. If I had the Quick Silver carb on again I would try Steve's technique to kick the engine over first with the enricher on, return it to the run position, and then crank the engine over.
The dyno test reveled 41.8 horse power at 7800 rpm with a very flat power band starting strong at 4800 rpm. I could see the engine blowing black smoke at high rpm. I also noted two exhaust leaks in the system. I was right next to the bike and the rear wheel was rock steady with no vibration. Everyone at the shop was looking at bike and one tech wanted to take it to the racetrack to see how it would do.
At this stage I was again considering selling the bike, or going all out and getting it to run perfect. I discussed my situation with another Internet Duke owner, Ron, who had the same feelings and problems with his bike. We both decided we couldn't get another bike with all the race components the Duke has for the price. We already owned the bike, so we were going to fix our bikes.
I ordered a Keihin 41-mm FCR carb from Sudco for $465 plus $15 for shipping. The carb came in five days with a new set of throttle cables. The only instruction with the carb was a small photocopied tuning instructions. To fully understand the instructions you had better have a basic understanding of carburetors. The switch took me about two and half-hours taking my time and going back to switch the throttle cables. One of the cables uses a larger fitting than the other at the grip. I routed the new cables just like the original even though the new throttle linkage is on the other side. The cables were attached to frame under the gas tank with tape (yes tape) and plastic ties as the factory had done.
It took a while for the bike to start and when it did it idled well but the engine ran very hot at idle. The new FCR has an accelerator pump and this gave the bike a low-end boost it never had before. Roll on wheelies were no problem. I now had to get use to this new low-end power. After a thorough test ride I found the bike to surge at mid throttle, idle very hot, and hard to start again when cold unless I pumped the throttle.
The tuning instructions and a call to Sudco confirmed that the bike was running lean. I lowered the clip on the needle one at a time until the surging just stopped. To adjust the main needle you have to take off the top of the carb, remove an Allen screw, pull out the needle, and reposition the clip. The side fairing and gas tank have to be removed for this operation. I got to do it in less than twenty minutes. I now had only one position left to go on the needle. The bike would now run well above one-quarter throttle.
Next, I adjusted the idle screw out until I got the engine to run without getting hot at idle. I did this a quarter turn at a time. To adjust the idle screw you need to remove the sides and the tank again, loosed the screw clamps that hold the carb, and rotate the carb out away from the bike. All of this because the needle is on the bottom of the fuel bowel. The idle screw is now out 2- 3/4 turns. I am at sea level and believe this carb was setup for a higher elevation.
The engine now starts when cold with two pumps of the throttle and cracking open the throttle a bit. The bike runs great but has a slight surge at 1/8 throttle. After talking with a shop and Sudco it was determined that I need a larger pilot jet. I bought one from the local shop for $3.00. Sudco said these were the same jet most Kawasaki's used.
I removed the old pilot jet and looked at the new on. There was not a heck of a lot of difference. I installed the new jet and readjusted the idle screw to one and a quarter turns. The bike started right and idled at a lower rpm than before. The bike ran overall very well. It also idled when cold perfectly.
I took the bike to a new dyno shop and had them use the exhaust analyzer too. They reported that the bike was burning the right amount of fuel and were quite surprised IU got to run that way myself. The bike now put out 41.5 hp at 7800 rpm again. I asked them about the difference between the last run, and they reported that different dyno machines could be a little off. The bike was backfiring when the throttle was released at high rpm in lower gears. It was quite a bang. The shop said it was common in these types of bikes. The power band was pretty flat starting around 6800 rpm.
If the throttle flicked open from idle at a light thee engine would die. This I believe is from too low an idle speed (around 1400 rpm). I had the bike before at 1800 rpm, but with the new pilot jet I can't get the idle lower. I will have to take the carb off and see what's wrong with the linkage or if it's a leak.
Overall
The new carb was worth changing. The bike runs much better and will start anytime. Something it didn't do with the Quick Silver. Ron, on the other hand, reported swapping out his carb and the bike running perfect. He is up North a bit from me and maybe the jetting was all right for him. He has added a pipe and the combination is putting out about 47 hp. I looked at the dyno run of another Duke owner with a custom made D&D exhaust and his is putting out about 46 hp with a 41mm Mikuni carb. 47 hp on a light motorcycle is not bad performance. I believe there is still more to get out of the Duke and will go at it on step at a time.
Living with the duke has been a love hate relationship, with more love after getting the bike running well. In the looks department I can't say enough. Everywhere I go people stop and ask about the bike. Other bike riders admire the polished wheels and the brembo brakes. The dirt riders always ask about the Taperpro handlebar. The bike is very light and easy to move around. I can get some really scary lean angles and the bike just hangs in there. I credit the good tire for this. I scrapped the foot peg the other day. The suspension has been great, fully adjustable. I only get about 80 miles to the tank before I start looking for a gas station. The reserve give me about 15 to 20 miles before you have to start pushing. The bike has not leaked a drop of fluids in two years and the tires have not lost any air. The rear brakes squeak a lot.
The only problem has been when a rider I passed on a scooter came up to me at a light and gave me the charcoal canister that fell off as I passed him. I bought him a coke and we laughed about it. The gas tank vent line burned against the exhaust and stained it. I will reroute it to the lower frame.
What's next
I will order a richer main and needle this week in anticipation of adding a pipe and a new air filter. First I am going to change the air filter to a K&N. I plan on lowering the bike about an inch to an inch and a quarter. Then I am going to work on the exhaust. After that I will go with a new piston and cam (can't change the cam without changing the piston I am told by KTM and Megacycle) and have some head work done by dale Walker. At that point I will leave it alone.
I will update this review as I make changes to the bike and report new findings. Anybody that want's to write me to discuss the Duke please feel free. To many new Internet friends who have helped get this bike running right, I say thank you.

Tom Avello ( tavello@worldnet.att.net )
03/28/99