Pablo's DR350

[Pablo83]

I have been riding a plated '01 Yamaha WR426 for the last few years and it's a very capable bike, but I'd like something that requires less maintenance and has a six speed gearbox. As part of my low maintenance requirement, I wanted something air-cooled. After researching many bikes, it appears that the DR350 is the largest displacement air-cooled dirt bike that come with a 6-speed tranny and and weighs less than 300 lbs.

So last winter I bought a '98 DR350 kicker.

[Pablo83]

The first thing I noticed about the 350 is it appears to have a hinge somewhere in the middle of the bike. I had heard that the frame on this bike is very flexible and that turns out to be the case. I got used to the handling pretty quick, but this is still something I want to fix.

Shortly after buying the bike I found a used 440cc big bore kit for it on CL, it appears to be a kit sold by Jesse a while back. I have yet to install it.

After reading this post in DisTech's DR350 rebuild (which has been a real inspiration), I decided I wanted the DR250S's tranny. I recently acquired the second half of my winter project, a '91 DR250S. Here are my two DR's:

[Pablo83]

So here's the plan...

From the 250 I will use:
Frame (since it's a titled, street-legal vehicle)
Tranny
Rear hub (has cush drive)
Wiring (assuming the 250's alternator rotor will fit on the 350's crank).

From the 350 I will use:
Crank
Head
Suspension - I understand the '98 kicker has cartridge forks and the 250 only has damper rods.

Additional modifications will include:
440cc big bore kit
Removing the "hinge" - I think a big cause of this is the 3-piece C-section swingarm. The plan is to weld the swingarm arms to the center section and use some aluminum strap to box in the C-section arms. A fork brace wouldn't hurt either.

More input is welcome, just keep in mind this will be a budget build (no USD suspension, FCR carb, or Vortex air-box [although I might build my own airbox as the stock one is clearly restrictive])

[Pablo83]

Thread index:

Boxing the swingarm

What to look for when buying a used DR350.

The shift drum bolt issue

Oversized Clarke tank
Oversized Clarke tank II
Clarke vs Acerbis tanks

Resolving the clutch drag issue

Skidplate
Skidplate part II

Fork swap

weld-on peg extensions

Front brake rotor

removing the kickstand switch

Longer shift lever

Replacing the battery with a capacitor

Rear rack

Bike weights

The circlip issue

Tranny swap - this was pretty straight-forward, but if you want more details, you should read the entire thread as there are a number of differences between the two engines that are worth noting.

[ShooterDave]

WOW. That is quite a winter project. Good luck and keep us posted. I don't own either of these but am interested in following your progress.

[plugeye]

i like the sound of this

[Pablo83]

I spent this morning re-reading DisTech's build. There's an enormous amount of information there. I just need to clean some Transalp parts out of the shop before I start this build.

[CodeMonkee]

http://www.kientech.com/

Jesse Kientz is the man to go to for DR350 parts, mods and knowledge.

[Pablo83]

Since this is a budget build, I'll try to track the cost of everything since some people seem to be interested in that kind of thing. Items begin with N or U for new or used.

U 98 DR350 - $1100
U 91 DR250S - $950
U 440 big bore kit - $175
Acerbis tank $207
aluminum plate for swingarm: $98
peg extension $30 (I think)
Cycra hand guards w/ ATV mounts: like $110 I think
protaper bars $70ish

[EDIT] shortly after posting this list I stopped keeping track. I certainly went way over budget. Overall I would guess this bike is slightly cheaper to maintain than a modern CRF/WR/RFS, but not a whole lot cheaper.

[Kawidad]

Originally Posted by pablo83

So here's the plan...


Suspension - I heard a report somewhere that the '98 kicker has better suspension. I need to do some research to find out if that's true.

Yes it is true. The 98 and beyond had cartridge forks that were sourced from the previous generation RM race bikes. Also, they improved the shock, IIRC, they were also sourced from the RM. In addition, the brakes were RM brakes. So, all in all, big improvements.

[Pablo83]

Just a little background on the project...

In college I rode a friend's chopped out GS1100 with open headers. It was an absolute turd. I really didn't have much respect for Suzuki's after that.

A while back it seemed like everyone was trying to get me to buy a KTM, but I had the impression they were terribly unreliable, so I did a survey to try and understand if my impression of KTM's was true. That survey is here. There's a lot of information there, so the short form is, I tried to find the percent of people that rode each type of bike and compare that with the problems reported on each type. The data showed that KTM's were unreliable*, but the more surprising thing I learned from the survey was how many ADVers rode Suzuki's, and how few problems they reported.

It was because of this survey that I started looking at Suzuki dirt bikes.

*Now that I have a better understanding of KTM products and I have gone over the data again, it turns out that about 90% of the reported problems are with the LC4/8 engines which means the RFS engines are probably just as reliable as the Japanese manufactured bikes.

[Pablo83]

Originally Posted by Kawidad

Yes it is true. The 98 and beyond had cartridge forks that were sourced from the previous generation RM race bikes. Also, they improved the shock, IIRC, they were also sourced from the RM. In addition, the brakes were RM brakes. So, all in all, big improvements.

Thanks!

[motoman250f]

I would really try a fork brace before making a bunch of changes. it makes a huge difference.. Cool Project!

[Pablo83]

Originally Posted by motoman250f

I would really try a fork brace before making a bunch of changes. it makes a huge difference.. Cool Project!

For the front, I'm tentatively planning on just adding a brace. Do you use one? If so, what brand and how do you like it?

[DisTech]

Awesome!

You will need to get a DR350SE crank and starter clutch set (starter clutch, bearing and gear). I think the magneto will work but the dirt crank does not have room for a starter clutch set. Some pictures, here.

Can't wait to see how you box the swingarm and how the bike turns out!