DisTech's DR350 rebuild

[BSR-1]

sounds like you've got many fun filled nights in the garage ahead!

[Phreaky Phil]

I hope to make mine look something like this one, but with a bigger tank.

[DisTech]

Originally Posted by BikePilot

Yep re the airbox, there were a few other places selling them too I think (cyclegear for one). As far as I know they are no longer available. I got mine used on e-bay. Its missing the side cover, but otherwise intact and the cover is just a flat bit that should be easy to fab up.

I don't know a lot about the FCR - I didn't think about you already having the TM33SS - might as well use that for now. I know a few folks have FCR's fitted and working. Sudco sells manifolds in various sizes. It would probably be a hassle to get it all fitted up, but once done would flow better and provide a bit more percise tuning options. Only really worth doing after you've got the cam and big bore and even then you'll need to do some pretty serious head porting to match up with the larger carb bore. I think G-man on maximum-suzuki has posted up some specifics on this. I can't run the FCR as my DR's are e-start and there's physically not enough space so I haven't looked into it too closely.

I didn't realize the megacycle cam came with the Ti retainers - I imagine they work just fine. I'm still on a stock cam, though I am running the kibblewhite springs and ti retainers just to make sure there's no way I can float the valves should I get a bit frisky with a downshift at high rpms.

I don't think thumper racing still boxes the swingarms, but I haven't checked to verify. They used to sell plates that fit inside the rear C-section of the swingarm which were then TIG welded in. It wouldn't be hard to cut out such plates if you happend to gain access to a mill ( could also be done with less sophisitcated means, but a mill would make it easy).

Oh, you might as well be on the lookout for stiffer springs for the KTM forks - the Dr is quite a bit heavier than the KTM and will have even more weight on the front wheel once you put in 4+ gal of gas (that's about 26lbs I belive). Guessing about .46kg should be rougly correct. It will certainly be rideable (and probably still a lot better than stock) with the stock KTM forks so no rush there.

have fun

I'll see if Jesse still sells the airbox. TM33?! Now you've gone and got me looking at the FCR37!! I did see the manifold chart at Sudco. The FCR37's aren't that expensive and there are quite a few on ebay. I'm still searching for swingarm stiffening. I had to respring my DR650 so I was expecting that on the DR350 as well (I should add that to the todo list). Thanks.

[DisTech]

Originally Posted by BSR-1

sounds like you've got many fun filled nights in the garage ahead!

Odometer: 1? I swear I've seen you on ADV before. Thanks for joining.

[DisTech]

Originally Posted by Phreaky Phil

I hope to make mine look something like this one, but with a bigger tank.

Oh man that is fine! And damn it's got WP forks too. Here is my inspiration.


It's Boomhauer's over at maximum-suzuki.

[BSR-1]

Originally Posted by DisTech

Odometer: 1? I swear I've seen you on ADV before. Thanks for joining.

I'm sure I'd posted before but I haven't been on in a while.
It still remembered my login but my post count was gone.

[Phreaky Phil]

Originally Posted by DisTech

Oh man that is fine! And damn it's got WP forks too. Here is my inspiration.


It's Boomhauer's over at maximum-suzuki.

That is sweet too.!! I searched for info on the swingarm stuff. Apparently an RMX250 one will fit and I think some RM125 ones will but im not convinced its necessary. In my past experience the shock makes the biggest difference. Ive used Ohlins on several bikes and the difference is like night and day

[Phreaky Phil]

This bike only has stock swingarm but an Ohlins shock, and an RM front end

[Kawidad]

Originally Posted by Phreaky Phil

I searched for info on the swingarm stuff. Apparently an RMX250 one will fit and I think some RM125 ones will but im not convinced its necessary. In my past experience the shock makes the biggest difference. Ive used Ohlins on several bikes and the difference is like night and day

That was going to be my suggestion. It will bolt up directly. The best option is to find a wrecked RMX, the later the better. 1997 and up? That's because they came with the RM forks, which also bolted directly up to the DR. I know you already have the boingers, but.............

[BikePilot]

Its not a direct bolt up - the RMX swinger is designed to mount to the outside of the engine cases, using the engine cases as a stressed member. The DR swingarm is solid across the front.

[procycle]

Originally Posted by DisTech

Thanks, Jeff. That's good news about the cylinder. BSR-1 said the same thing about the head. Since we are talking about big bore options, is there any 480 news?

Just getting the motor back together for the 2nd time.
I blew it up on the dyno but that was after seeing 40hp





To take advantage of the FCR37 you will have to do some significant porting work. The intake port is right at 33mm. Not much point in using a carb that is bigger then the port.

[BSR-1]

Originally Posted by procycle

Just getting the motor back together for the 2nd time.
I blew it up on the dyno but that was after seeing 40hp





To take advantage of the FCR37 you will have to do some significant porting work. The intake port is right at 33mm. Not much point in using a carb that is bigger then the port.

Awesome results Jeff!

any Idea what was the cause of the motor blowing?
I mean, what will stop it from happening again?

[Fubars]

This thread has me jones-ing for a 350 right now. Forgot to mention--I like this workstand. I'd build one, but I'm in the middle of a 40mm WP conversion on my 650.

Originally Posted by DisTech

[procycle]

Originally Posted by BSR-1

any Idea what was the cause of the motor blowing?
I mean, what will stop it from happening again?

Definitely detonation. It toasted the piston but didn't hurt anything else.
It took several runs to get the jetting in the ballpark. Those early poorly jetted runs took their toll.

I changed shape of the top of the new piston to give it a little more squish area - that should help.

The thing that is most amazing to me is this motor was breathing through the stock TM33 carb, the ports had not been touched and the valves, seats and guides were all worn out.

[BSR-1]

Originally Posted by procycle

Definitely detonation. It toasted the piston but didn't hurt anything else.
It took several runs to get the jetting in the ballpark. Those early poorly jetted runs took their toll.

I changed shape of the top of the new piston to give it a little more squish area - that should help.

The thing that is most amazing to me is this motor was breathing through the stock TM33 carb, the ports had not been touched and the valves, seats and guides were all worn out.

It sounds like there's quite a bit of untapped potential there.