My Anti-Tension Kutentraub enduro build

[Rot Box]

I've been wanting a street legal bike for awhile and it seems lately I've missed some pretty awesome trips because I don't have one I prefer to ride two strokes however I decided that if I do go the street legal route I want a 4 stroke and I want a BIG BORE 4 stroke with lots of grunt! :greg: I love different and I really like simple/reliable so the bike I picked should fit both quite well. I've had this bike for awhile and I picked it up for $100 instantly falling in love with its rarity and uniqueness. It is a ATK with a Rotax 560 4valve engine. Only the best components were used at the time and the bike weighs in dry at 248lbs (beat that YZ400--1998's new lightest production motocross bred 4stroke ever made @ 250lbs ) and it is very rare which is good and bad.

Here is a pic when I first bought it:

The name ATK comes from the chain routing design that eliminates the chain tension that causes the rear suspension to become "nearly rigid" on other bikes. I can say from experience that the system works very well, but due to the amount of moving parts I don't think it is very practical :-\

Anyway being an old neglected bike I decided to rebuild the top end and install a new set of rings (almost $200 with shipping ) and honed the cylinder. I also went though and cleaned up the frame and chassis.

The over head cam is actually driven by a belt.

 

[Rot Box]

The header pipe was rusted through on the bottom so with the help of a buddy we made a custom patch that worked out great. While I could have replaced the header I figured I'd save myself a lot of money going this route. While it was off I replaced the copper seals between it and the head.

 

[Rot Box]

The brake cylinders up front were completely blown out and the rotor was completely shot. ATK used one of the first production WP inverted fork setups and while the fork action was pretty good they are still old and outdated.

Rather than trying to track down non-existent brake parts I decided to upgrade. I installed a set of Paioli "Blue Tube" conventionals with 46mm tubes. With that comes much better Brembo brakes (oversize rotor) and a Talon/Excel wheel. In the day the forks alone were a $3500 as good as it gets setup in the late 90's and I scored them for free :greg:

 

[Caleb]

I'll be watching this.

 

[anderson750]

Unique is a good word todescribe this bike. I remember seeing a few of thes back in the day. This will be interesting to see as it comes together.

 

[Rot Box]

I'm really getting excited and everything is really starting to fall into place. One thing I can't wait to take advantage of is the stock 190W lighting coil I'm probably going to bug you guy's about wiring everything up though--I'm a complete newb when it comes to lighting.

I'm trying to figure out the plus and minus of running a battery. What do you guy's think?

Andrew

 

[rholbrook]

I'm really getting excited and everything is really starting to fall into place. One thing I can't wait to take advantage of is the stock 190W lighting coil I'm probably going to bug you guy's about wiring everything up though--I'm a complete newb when it comes to lighting.

I'm trying to figure out the plus and minus of running a battery. What do you guy's think?

Andrew

Corban rides a very capable plated ATK. I know he has wired and rewired his so he would be a great mentor on this for you. Where are you Corban?

Here is your battery option.
http://www.thumpertalk.com/forum/showthread.php?t=788588&highlight=turn+tech+5a+battery

 

[Gravy]

throw that thing on the bathroom scale. I'd like to see what it really weighs

 

[redXJ]

subscribed!

 

[Corban_White]

throw that thing on the bathroom scale. I'd like to see what it really weighs

Yep. I wanna see that claimed weight. Glad to help with the wiring when you are ready.

 

[Rot Box]

throw that thing on the bathroom scale. I'd like to see what it really weighs

Yep. I wanna see that claimed weight. Glad to help with the wiring when you are ready.

Ha Ha I thought that might get some attention. I'll put it on one as soon as I get the chance because despite what I believe I'm still having trouble wrapping my head around it. It definitely feels as light as my last 98 KTM300 at this point in owning it. Fwiw early California (Utah bikes are closer to 290-300lbs) built ATK's have been sold with a dry "claimed" weight as low as 247lbs in the late 80's. ADB still offers a very similar bike (same engine) http://americandirtbike.com/toppage1.htm with a dry weight of 259lbs in motorcross trim like mine. Only a scale can tell for sure though


Thanks a bunch Corban! Test fitting the new headlight assembly tonight

 

[Jared]

the bike weighs in dry at 148lbs

This is a typo, right? I assume you mean 248. I'm betting the motor weighs in at 90+ alone.

Jared

 

[Rot Box]

Wow I feel dumb! Yes 248lbs is the claimed dry weight. Sorry for the confusion everyone I was wondering what all the fuss was a about.

Just trying to fit on some later model plastic. Protaper bars, Domino twist throttle and a headlight shell from a later ATK should work for now. If this thing proves to be reliable I plan on installing a much larger/higher wattage headlight. With the Brembo's bled I'm certain that the brakes are going to be much better than what came stock.

 

[rholbrook]

Whew, that was close. Corban almost had to sell his ATK for your model.

My WR450 has a claimed DRY weight of 246 to 249 lbs which is nearly 30 lbs more than the YZ450.

Could you imagine how sweet of a KTM, CRFx or WR you could have for the money you put into buying an Avenger? How can they stay in business?

 

[Rot Box]

Could you imagine how sweet of a KTM, CRFx or WR you could have for the money you put into buying an Avenger? How can they stay in business?

The price is crazy huh! A replacement 604 engine alone is $4295+ shipping I don't know how many they sell annually but I doubt its very many. I think Keith runs his business mostly off of replacement parts and hard to find ATK stuff and he is awesome to work with. While the Rotax 560-604 is an incredible motor the they are dated (and heavy) and so is the suspension on the Avenger.

Speaking of the Rotax check out these cases: http://www.porterbrothers.co.uk/gallery_index.php?list=5 These guy's also offer fuel injection kits and packages with 75+ horse power

I'm building this one up because I'm not into it a lot of money and it has a great fun factor. Truth be told the only exotic I'd consider buying new is a Berg otherwise my money would be on a WR450 if I could afford one right now.

Andrew

 

[Rot Box]

Sorry nothing to report on the 560 project right now. I picked up two ATK 260 LQ's with lighting kits both completely disassembled right down to the last bolt so that has been my project lately. Here is what I ended up with--I took the best parts from each bike and put them together. The last thing to bolt on was the kick starter and I guess that is the only thing I didn't get in the deal Being that the engine is completely new I think it should fire right up, but I won't know without a kicker lol. Oh well I can't complain because I got it all for free

 

[phatfoto]

I need to find deals like these... Haven't rebuilt a bike from a pile of parts in 23 years.

 

[Rot Box]

I fired up the ol' girl over the Christmas weekend and it started up great! I was able to burn down the road on it and man this thing hauls and it feels very nimble.

Unfortunately the carb is shot and it was running very rich and crappy down low I just don't like the idea of having this particular carb (Mikuni TM flatslide) on a 4T bike so I'm going to keep an eye out for a Dellorto (comes stock on Utah built ATKs) with an accelerator pump or something crazy like a FCR Keihin we'll see.

Right now I have come to realize that I have way way--wayyyyyy too many irons in the fire so I'm putting everything on hold until my CR500 is put back together the way I want. Hopefully that will be sooner than later :-\

 

[rholbrook]

Right now I have come to realize that I have way way--wayyyyyy too many irons in the fire so I'm putting everything on hold until my CR500 is put back together the way I want. Hopefully that will be sooner than later :-\

Wife is finally reeling you in....just like the rest of us.

 

[Rot Box]

^ Funny how that works isn't it!