So I surveyed the riders I see occasionally around mods. From stock up yo stage 3. Of the nine Harley's, either ultras or SG"s all 6 that have been modified have had issues. Of the three that are stick one had a stator grommet leak. The other two stock no issues. My ultra 09 33 k miles. I am thinking the engineers who design these bikes design them as they are built. If we want another 20-50 HP I think we are opening the door to other issues. Maybe maybe not?

 

Depends on how wild you want to go. Im big on improving efficiency and building power that way. Better air flow, mild cams, mild compression increases, that sort of thing. Alot of times guys mod stuff to beat on it. That isnt good for it either. I always like power through efficiency and low stress

 

I think it depends on who is doing the mods and whether the owner spends enough to have them done right.

My 08 Softail puts out 107hp at the wheel after I had it blown out to 103 cu in.
I had it done by a guy whose done many of these, has the correct equipment and spent the dyno time to get the tune correct. Also upgraded the clutch and other key components. I've had no problems, but it was not a cheap date. Over 40K miles so far.

 

Are the issues the people are having dealing with the modded parts? Or are they completely unrelated? Say, for example, I did a stage one but am having issues with my rear brake caliper sticking, what side of your study am I on?

 

I wouldn't think you'd be even in the study any more than you would be if you installed a turbo and then got a flat tire. Unless of course your power increase caused extra heat which increased the temp of the brake fluid causing it to deteriorate and congeal in the caliper making the piston stick. I guess then that the power mod would be contributory to the brake failure, eh?

 

Sure. Any time you modify anything, you run the risk of it not running as intended. These machines were designed to operate reliably in stock configuration. Fortunately, between talented aftermarket engineers, mechanics, and robust tolerances in original design, there is a great body of knowledge out there for those willing to take up the challenge of functional modification.

Just understand that it isn't Harley's fault that your bike is acting funny after you've monkeyed with it.

GM

 

Which is why they try so diligently to void warranties. Once you have something done outside the norm and away from the dealer the moco will drop you like a hot potato. They are all about taking money in not putting money out.


But then I learned a long time ago that it's not so much what you do to the bike. Rather it's who does it that can make the difference between success and failure.

 

Depends. Who does the work matters as much or more than what is being done.

Remember - the HD engineer that designed the engine is the same one that then went out and designed the stage kits to upgrade it. So it should theoretically be the same.

 

One of my bikes, and the most heavily modded is an '02 Fatboy. I added a Dave Mackie Megasphere 95" kit with S&S gear drives on Dave Mackie cams, and a Screamin' Eagle six speed tranny in '05. It has 80 spoke wheels, a Mikuni Carb, a Screamin' Eagle adjustable ignition module and D&D Fat Cat exhaust. I ride my Roadglide more than this bike but I ride the Fat Boy around town a lot. After 12 years and nearly 60,000 miles it has never had a single problem. Just oil, tires, brakes and batteries. It's fun to ride, looks great, and is stone dependable!

 

Generally speaking, outside of the mild upgrades, the risk goes up. You get a motor to generate more power, its gonna run hotter, rev higher, put more stress on the internals.