DisTech's DR350 rebuild

Discussion in 'Thumpers' started by DisTech, Nov 27, 2009.

  1. PhiSig1071

    PhiSig1071 What's ******width?

    Joined:
    Apr 9, 2008
    Oddometer:
    2,573
    Location:
    Tucson, AZ
    Truly enjoyable read! For some reason I have an affinity for the DR350's. I think Suzuki made a huge mistake when they went to a 5-speed in the DRZ, and they seem poised to make the same mistake if they make a DS version of the RMX-Z. I love the idea of dropping the 6th from the 250 into it. You may have built the ultimate Dual-Sport machine when this is complete.
  2. BikePilot

    BikePilot Long timer

    Joined:
    Jul 5, 2005
    Oddometer:
    11,251
    Location:
    Tampa
    Thanks for the cam info - sounds like they are pretty close, at least in lift.

    I know my DR250SE turns more rpm than my 350 with the same gearing on both - IIRC its down to different primary drive ratios. Don't know if that matters to you.

    I personally wouldn't want any wider gear spread in the 350 I don't think - the gaps seem pretty well spaced as it is and I think the gearbox might feel pretty gappy if the gears were further apart (though perhaps just a taller 6th for freeway crusing might not hurt I guess).

    Anyway, have fun:clap
  3. Drif10

    Drif10 Accredited Jackass

    Joined:
    Jun 12, 2003
    Oddometer:
    46,765
    Location:
    Gates of Moscow
  4. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Thanks! Doesn't 11.5:1 455 with the taller high gears sound like a great dual sport combo!? I really wanted to 5th and 6th from the 250, but I couldn't find a set of 5th gears, discontinued. Jesse couldn't find a set either. I asked him if just putting the 6th gear set in would create to big of a gap from 5th to 6th and he said, Heck no! So I've got 6th drive and driven on order (they still haven't shipped though!:cry).
  5. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Ok BikePilot, you've mentioned the primary drive ratios differing a couple times now and I've read it on thumpertalk and maximum-suzuki. But I'll be damned if I could find documentation saying what the ratios are. Time to take advantage of three split cases!

    [​IMG]

    93 DR350 S (left)
    Primary Driven gear (NT:62)
    Primary Drive gear (NT:22)

    94 DR350 (center)
    Primary Driven gear (NT:64)
    Primary Drive gear (NT:20)
    Oil Pump Drive gear (NT:22)

    93 DR250 S (right)
    Primary Driven gear (NT:64)
    Primary Drive gear (NT:20)
    Oil Pump Drive gear (NT:22)

    Interesting. The 250 is the same as the dirt 350.

    Also interesting, since the 93 DR350 S Primary Drive gear and the Oil Pump Drive gear would have been the same size they just made one fat gear.

    Going to use the 350 dirt model transmission with the 455 so that makes me think the 250 6th gear set is a good idea. The other bike will be a 350 with the 350 street transmission and the regular 350 6th gearing. By chance I was going this route, but this information sure solidifies my plans.

    Thanks for the prompting BP.
  6. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Ughh...

    I was not careful with some gasket remover and bubbled the clear coat off a big portion of one of the 250 case halves. The case surface was pretty marred up so I read a few aluminum case restoring sites and decided to give it a try.
    [​IMG]

    Once the clear coat comes off all nicks and scratches immediately look ten times worse.
    [​IMG]

    Everything stripped and cleaned and I started polishing the magneto cover. The smallest, flattest, easiest piece took days to look not bad. I started working on the left case half with all those nooks and crannies :cry.
    [​IMG]

    Looking for other options...

    To get it sand blasted and powder coated, all the bearings will have to come out.

    Well, lesson learned. Be careful with gasket remover.
  7. yondering

    yondering Long timer

    Joined:
    Apr 6, 2009
    Oddometer:
    1,100
    Location:
    NW Wa. state
    Are you using that polishing compound by hand, or power tools? Sounds like you need a felt or muslin wheel on your cordless drill, and some polishing rouge. I'm using some white rouge on my buffer that cuts pretty fast but leaves a mirror surface.
    If you want to speed up the process you could wet sand it with 320 grit first, then buff it.
  8. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    I started by hand and then moved to a polishing wheel with a drill motor. That worked OK for the magneto cover because I could get at all sides. All the other case pieces have right angles and ridges that prevented the wheel from being effective.

    Considered a Dremel but ruled it out because of their tiny consumable polishing attachments were ridiculously priced.

    Then I bought a compressor and air tools... the 1/4" air rotary tool is has a good selection of reasonably priced polishing attachments.

    The case pieces are shinier but I still have the same problem with getting into the corners.

    Took the compressor back. Gonna look for a bigger quieter one on craigslist.
  9. BikePilot

    BikePilot Long timer

    Joined:
    Jul 5, 2005
    Oddometer:
    11,251
    Location:
    Tampa
    I had a KX250 that the PO had done a lot of nice work to (he was a friend and then a AA/Pro racer). The swingarm and cases had all been blasted - I'm not entirely sure with what - I'm guessing walnut shells. It left a really nice, flat, very slightly dimpled finish without any signs of errorsion. Of course the bike was kept really tidy (he was the sort that would wash the bike at the track immediately after the ride with a toothbrush, then wipe down with Wd40 before going home) and there probably weren't in surface imperfections before the blasting.

    Anyway, I would definitely not use sand or glass media as it'll tend to get embedded in the cases and might make its way out and into the oil if you accidentally blast the inside of the case. Walnut or similar would be much safer.

    Good to see solid proof of the primary drive ratio differences - I think I found the ratios in a suzuki manual at some point but don't remember for sure how I came to that conclusion (that and riding both my 2 drs makes it obvious that something is different).
  10. yondering

    yondering Long timer

    Joined:
    Apr 6, 2009
    Oddometer:
    1,100
    Location:
    NW Wa. state
    Glass beads in the oil and bearings would definitely be a concern, because it tends to get everywhere, but it will not embed in the cases. They would need to be very thoroughly cleaned though.

    The finish you describe on your friends bike sounds like glass bead; it leaves a slightly shiny/sparkly matte finish, almost like a styrofoam take-out box, but less glossy. Not a dull surface like sand blasting though.
    Walnut won't do anything for the corrosion in the cases; it's not a hard enough media. It is good for cleaning and paint removal, but won't significantly alter the finish of the aluminum.

    DisTech, if you give up on the polishing, and want to go ahead and glass bead the cases, you are welcome to use my bead blaster, I'm just a couple hours north. You'd definitely need to remove the bearings first though, as you said; sounds like a real pain.
  11. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Thanks for the offer yondering, I may take you up on that. For pulling the bearings I just ordered this:

    Mountain (MTN9001)
    Pilot Bearing Puller
    [​IMG]

    Features and Benefits:

    When working space is limited, this type of puller is needed to remove flywheel pilot bearings from automobiles, trucks, and tractors

    • Only 7 1/2" long
    • Can also be used to pull bearings or bushings from generators or starters
    • Includes 1/2" to 1 1/4" ID Capacity jaws
    • Strength - helps pull out tough bearings
    • Short length - allows reach into tighter areas
    • Versatility - works on automobiles, trucks, and tractors
    • Made in the U.S.A.

    There are lots of pilot bearing pullers but most have 3/4" ID jaws. The 1/2" ID jaws are required for most of the bearings in the case and took a little digging to find. I hope it works!
  12. procycle

    procycle Long timer

    Joined:
    Jun 7, 2007
    Oddometer:
    2,555
    Location:
    Center of the DR650 universe
    The easier way to remove the bearings is to put the case half in an oven. Heat for about 1/2 hour at 350 degrees and the bearings will fall right out.

    The oven works just as good when it's time to put the bearings back in. Heat up the case and just drop the bearings into their holes.
  13. procycle

    procycle Long timer

    Joined:
    Jun 7, 2007
    Oddometer:
    2,555
    Location:
    Center of the DR650 universe
    I have had great results blasting with soda. This is a special crystallized formulation of baking soda. Clean up after blasting is with hot soapy water. There's no concern about getting it the bearings because it dissolves in the water and rinses away.
  14. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    The right half of the case was easy to get the bearings out because they could all be tapped out from the opposite side. The left half of the case is a different story because there are two bearings that can only be accessed from one side.

    First I'm giving Jeff's oven method a try! Preheating to 350.
    [​IMG]

    After 15 minutes the house smelled like motor oil casserole and one of the bearing dropped out!
    [​IMG]

    I went up to 45 minutes and the other bearing was still tight in place. Oh well, 50% success with the oven!

    Good thing for the backup pilot bearing puller. After a lot of farting around, filing the jaws so they would not just pullout without the bearing, success!
    [​IMG]

    [​IMG]
  15. Mezo

    Mezo Banned

    Joined:
    Nov 17, 2008
    Oddometer:
    2,129
    Location:
    Brisbane,Australia.
    Thats' a nice little puller you guys make all the handy tools, we just get the usual cheap Chinese crap that breaks on its first use.

    Like valve guides & valve seats, put the bearings in the freezer a day before & they go in real easy after you warm the cases.

    Mezo. :lurk
  16. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    The trick was finding one that worked for 1/2" shaft. There's lots of them that start at 3/4".
  17. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Bad news, the taller 6th gears from the early 250's are also being discontinued (like the 5th already is). I tried several different sources and I could find a 6th drive but no 6th driven.:cry

    Good news, no more waiting to build the 455!

    Mezo the freezer sounds like a good idea, but I didn't want to wait overnight so I tried Jesse's suggestion. Use a torch to heat the case until it hot enough to bubble spit, and then the bearings will drop right in. Sure enough, the bearing on the crank almost felt loose it dropped in so easy.
    [​IMG]

    When the Moon is in the Seventh House and Jupiter aligns with Mars then peace will guide the planets and love will steer the stars...
    [​IMG]

    I used the countershaft and driveshaft assemblies from my 93 DR350S because the gears were in better shape than the 94 dirt model.
    [​IMG]

    Ran through all the gears to make sure I had all the forks and cams where they should be.
    [​IMG]

    Gooped up! Can't hardly tell from the photo, but there is gasket maker a all over the place.
    [​IMG]

    Flipped over and bolted up.
    [​IMG]

    Flipped back over and done for the night.
    [​IMG]
  18. procycle

    procycle Long timer

    Joined:
    Jun 7, 2007
    Oddometer:
    2,555
    Location:
    Center of the DR650 universe
    For the bearings that don't fall out on their own I just make sure I have a wooden block handy. Just hold the case upside down and smack it against the wooden block. That will pop out all but the most stubborn bearings.
  19. zipper2680

    zipper2680 couch traveller

    Joined:
    May 16, 2009
    Oddometer:
    67
    Location:
    Portugal
    Looks good...keep it rolling!! :freaky
  20. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    616
    Location:
    Seattle
    Keeping it rolling!

    Cam chain sprocket and key.
    [​IMG]

    Primary drive and oil pump drive.
    [​IMG]

    Took me a minute to realize the gear shift stopper can only go on one way, the pins are off center from the center bolt hole.
    [​IMG]

    Here is the new beastly 8mm Kientech gearshift stopper bolt.
    [​IMG]

    Screws and bolt loctited in place. Doh! Blindly following the manual, they don't tell you to put in the tensioner that's under the gearshift stopper.
    [​IMG]

    Got it in anyway.
    [​IMG]

    Gearshift shaft and kick start shaft in place.
    [​IMG]

    Oil pump driven gear.
    [​IMG]

    Kick start driven(?) gear is also not mentioned in the manual under reassembly. Glad I didn't torque the clutch in place and then notice it.
    [​IMG]

    Primary driven gear.
    [​IMG]

    Clutch in place.
    [​IMG]

    Close the right side up tomorrow.

    The other bike it progressing as well. De-greased the 250 case (that I pulled all the bearings out of) at work yesterday and took it to Seattle Powder Coating for sand blast and pc.