Tuesday, April 30, 2013


Here is a helpful video guide for the Rotax Type 348 Cam Belt Change from a Harley Armstrong MT350:

Here's a step by step Google doc
Thanks to Pantera from the ATK riders forum for the find.


Whether it is due to excess vibration or poor welding, it is not uncommon for the ATK owner to experience some weld failures on the rear subframe where the side number plate mounting bracket resides. There is also a contingent of ATK owners who who would like to find suitable replacement plastics for their ATK, but must turn to the available UFO KTM plastics (1996 ktm 300exc) as an alternative and thus have to relocate their mounting brackets. I found myself in the previous category rather than the latter, and after finding a local art welder (with a significant understanding of TIG welding thin aluminum), I had my panels secured for beer money.

While I was getting the bracket rewelded, I took the opportunity to replace the 12 mm bolts with 5 mm Allens for easier disassembly.

Cost: $20.00


There are dreamers, and then there are dreamers, and then there are dreamers who will fabricate the crap out of something. The ATK based Snocycle is one of them. Now I feel bad for feeling bad about having to get a spacer fabricated for wheel fitment.

Images taken from: Snocycle

Sunday, April 28, 2013


If like most people looking to supermoto (verb) an ATK, you turn to Google for inspiration. In turn, you will run across the very familiar pictures that Chucky (on the ATK forum) A.K.A. Michelangelo (on the supermotojunkie forum). His bike has provided an artistic accomplishment in motard'ing an ATK, since I have seen so many "not so good looking" ATK motards. Perhaps it is the custom headlight, or the custom cut side panels, or maybe the powder coated swing arm, but whatever the "It Factor" is, this bike has it. Unfortunately he has since sold it, and we must be content to peruse the pics that remain in better times when cash could be rolled and Rotaxes roared the open plains!

Images taken from: Supermotojunkie.com


Not uncommonly, my desire to change my motorcycle from a perfectly happy healthy state of being into something different was not uninspired. Bones is one of those people that has taken the canvas of the ATK 605 and transformed it into many different states of awesome. From the older full frame 1995 701 SM conversion, to the 1999 605 full dual sport outfitted monster, he has managed to make a beautiful machine even more magnificent. A master of machinery, an Alaskan ATK muse, a man of vision and purpose: BONES.

Bones' SMUGMUG account for more detailed pics of each build.


Here is a comprehensive list of valve measurements for the Rotax Type 348 engine.

Information from Peak Riders


Wonder how much Horsepower your engine is making? Wonder what the factory compression ratio was? Well, here is some data for the Rotax 348 engine, which looking at my own engine, I should be at 37 horsepower at 7000 rpm with a compression ratio of 9.2. Makes you wonder, what a slight increase in compression would result in performance??? Hmmmmmmmmm....

All information from Peak Riders


From the time I got the bike, I was impressed by the deep guttural sound that emanated from it's stock Supertrapp exhaust. The tinny whine of the starter to the roar of life that kicked over was always satisfying (along with the joy of an electric start with a left side kick bike). It seemed strange that a single cylinder 494 cc engine would have such a grunt, and my curiosity got the better of me and I needed to take it apart, and good thing I did.

The poor excuse of a birds nest of insulation material that greeted me when I removed the end cap was amazing.

After 10 years, this was all that remained of what I assume was the factory muffler packing

I repacked it with regular old muffler packing available from my local motorcycle shop. NOTE: Wear latex gloves and long sleeves! Here is a tutorial video of How to repack a Supertrapp muffler When it was all back together, I replaced the ho-hum stock end cap with one from Amazon.

Turned out a lot cleaner looking than stock for less than 20 bucks! The sound was just as impressive, but a lot cleaner as well.

Part # Unavailable (Silent Sport Muffler Pack from Denmark found in local ATV repair shop bargain bin) Part # 402-3046
Packing Cost: $10 End Cap Cost: $18.69


Well, the fender change was enough to make me want to try to freshen up the overall look of the now 10 year old bike. The next easy modification was removing the peeling decals and super custom reflective swing arm tape. I was then left with the awkward red / black original ATK seat, which didn't seem to match anything.

After seeing Zuminazx's bike on the ATK forum I put in an order to GUTS and 65 dollars later I was rewarded with new black goodness. The material is a heavy duty durable nylon, but the graphics differed than the ones showed on the website, so you should be aware that yours may be different as well.

I followed the instructions to staple the front then the back, and work your way to the middle, and with a little elbow grease it all set nicely over the old seat cover (Yeah, maybe I was lazy).

Note: The seat plastic is VERY hard, and it required the heaviest duty staple gun I could find.

Part # 17404-21-21
Cost: $65.90 + CA tax and shipping = $86.98


Using my bike as a commuter I was regularly doing 55 mph + to and from school on the farm to market roads. Knobbies proved not favorable in these conditions, so I threw on some Pirelli Scorpions that the previous owner threw in with the deal that were take-offs from his KTM 990. But after I swapped out the tires, I noticed that the stock fender did a lot of "wandering."

In attempt to remedy this I searched out what looked like a good option, a UFO replacement for KTM 525 fenders that appeared to have extra "support" from a second piece of black plastic. It turns out that Husqavarna has employed the extra piece of plastic, whereas the KTM had applied a light black coating which provided little to no extra support, and "wandering" continued.

I dealt with it for a while, but when I came across a white Acerbis SM fender for 10 bucks in the bargain bin at the local shop I jumped, and will never look back. I made a template for the Paoli fender mounting bolt pattern and after minor drilling, it was done. It is stable at speed and since the majority of my riding involves little to no mud being sling into the air, I feel it is an appropriate choice for my needs.

I really liked the look of the two tone KTM fender.

So I roughed up the plastic and taped off the pattern, and using a plastic specific gloss black spray paint and some local stickers, BOOM!

After transferring the speedo cable routing bracket from the original fender I ended up with a final result that I was really happy with.

Part # 2040390002
Cost: $10 (bargain bin at local KTM dealership)


1999 490 DSES purchased used in 2010 with 1500 miles on it.

The only modifications by the previous owners (2) were applying some custom duct tape around the vented mylar decals to keep them from peeling up, some uber custom reflective tape on the swingarms and license plate holder, and a strange circular plastic clip mounted to the top of the headlight assembly for some unknown purpose.

Of course everyone says if you buy an ATK, it already has the best of the best (Brembro brakes, Ohlins / Paoli suspension,Pro-Taper bars, Rotax engine) so don't need to spend a lot of money upgrading it. Well, idle hands are the devil's workshop, and I could only resist the temptation to tinker for so long.


I am starting this blog to amass the information I have found on the 1997-2003 ATK 350 / 490 / 605 single sided frame bikes. I hope to have a comprehensive collection of pictures, diagrams, and videos that help with maint and custom fabrication for these bikes. I will try to include costs, part #s, and links to vendors as well. But I'll probably just end up posting pictures of my bike in cool places, but for now, I'll keep my aspirations higher.