This write up covers my experience with installing the Dupli-Tech version of an aftermarket alternator conversion kit for those who choose not to replace a failed stator. I believe that these kits will only gain in popularity, and the more that’s written about them the better.
I chose the DT kit because I liked the way the alternator installed on the newly milled timing belt cover, there was no modifying other parts of the bike, and it ran off of the crankshaft as opposed to the cam.
It is a bit pricey at nearly $600; I would hope the price drops as more people order it.
My bike is a 1987 Interstate, and nearly all of the observations I’ll list relate to that bike. The only exceptions will pertain to my friend 2slim’s 84 model, on which he had already installed the conversion. Donn was an invaluable asset in the installation of the kit on my bike; I owe him a lot.
Ok, on to the installation!
With your kit you’ll receive installation instructions. I will amend certain portions of those instructions as they applied to my situation.
Shorten right timing belt cover per photo below
. While precision is not required, the instructions will tell you that the cut must break into the hole to clear the newly installed pulley on the crankshaft. I ended up grinding the cut around the hole further back; it was just too close to the pulley-and belt- for comfort. I would recommend cutting out a full 2/3 of the hole initially; there’s plenty of overlap from the new cover. A hacksaw works fine. This picture shows where I made the original cut.
And here you see how close the right tb cover is to the alternator belt, even after I ground back my original cut:
I also had to modify the new cover in 2 ways. First, I ground back the boss (I would call it a flange) on the inside of the center hole- it is also too close to the pulley and tended to catch the outer part of the belt when I tried to install it, even though it has a half-moon cut out already. Here you can see where that flange was pushing against the belt, and how I ground it back.
The other mod I had to do was cut a notch out to allow for the pickup coil wires clearance into the timing belt area. This is not needed on an 84 model because the wires are located at the rear of the engine. Trust me, though- if you crimp those wires during installation, the bike will definitely not run well! Donn had to grind a slight dip into an adaptor piece to allow clearance for a water outlet on his 84. Here's the notch:
When it comes time to install the new cover, it is necessary to remove all nuts that hold on the left side crash bar. The new timing belt cover is simply too long to install otherwise. You don’t have to remove the crash bar, just let it pivot downward out of the way.
Important! As you begin to position the cover into place, do not secure it! If you do the crash bar will not clear the cover and you won’t be able to get it back in place. Get the cover close to position and swing the crash bar back up over it; then you can secure the cover.
When installing the alternator onto the tb cover, I fashioned a “hook” out of a short length (4 or 5 inches) of metal clothes hanger to assist in getting the belt onto the alternator pulley. (The belt itself is inside the tb cover.)
The radiator extension bolts are necessary for the radiator to clear the cover, but it makes replacing the lower radiator hose not a lot of fun. The NAPA part number for the hose is 8101- you have to cut some off of each end- and for me it was a chore. Donn had no trouble, though. I also found that the extension bolts threw the bottom of the radiator out far enough to prevent the attachment of the lower piece that attaches to both lower fairings. For me, that was not a big deal- it may be to you. I believe that piece could be attached with some trimming. The next two photos show what I mean:
Wiring is not difficult, but remember this: the charging indicator lamp that comes with the kit only lights up when the key is initially turned on- it will go out when the engine is started. That first light up just shows that the system is hooked up and operating correctly. And I’ll tell ya that a multitester showing a battery being charged is a beautiful thing!
All in all, this was a difficult install for me. I put on and took off the new timing belt cover half a dozen times. Knowing the necessary modifications would have helped immensely. You should just be able to hold the cover in place once to verify whether these mods are needed for your bike. Good luck- and I'll be happy to help in any way I can. Here is the end result: