DisTech's DR350 rebuild

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

  1. BSR-1

    BSR-1 Adventurer

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    Sep 13, 2008
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    19
    there's something wrong with those valves but I can't quite put my finger on it.......
  2. Mulekick

    Mulekick 2.7 on Fu Man Chu

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    Wow...someone went to a lot of trouble to trash that bike!

    Good onya for taking the time to bring her back from the dead!

    :lurk
  3. Mezo

    Mezo Banned

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    :poser

    DisTech, you could have done a nice moving gif with them four valves :evil

    My late father George (mezporting) used to repair heads damaged by dropped valves, here is just one example of his work.

    [​IMG] and after [​IMG]

    That would have been a rare head to be worth the repair.

    Mezo.
  4. brucifer

    brucifer Long timer

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    That's some impressive work there.
  5. DisTech

    DisTech Been here awhile

    Joined:
    Sep 3, 2008
    Oddometer:
    643
    Location:
    Seattle
    Jesse called me last Friday and suggested I take care of a couple things while everything is torn down.
    1. Balancer drive gear pin - beginning in 94 Suzuki drilled the pin set hole all the way through the crank.
      [​IMG]
      The balancer drive gear pin can work its way through the crank and cause damage. Jesse will press an additional pin into the crank, effectively making it like the 93 where the hole doesn't go all the way through.
    2. Cam driven gear bolt - the bolt is 6mm that cannot be torqued much and tends to break compared with most bikes of this size/class that have an 8mm bolt. Jesse will machine the gearshift cam and the cam stopper to allow an 8mm bolt.
      [​IMG]

    In order to send Jesse these parts I'll need to split the case on the 94. Now I have my new ebay $50 Tusk case splitter, here is the complete sequence!
    [​IMG]

    There she is! I must say having an assembled engine to look at for reference has been a tremendous help with figuring out the 93 basket case.
    [​IMG]

    Since I don't have special tool,

    • 09930-34912: Rotor remover
    to get the magneto rotor off I had to improvise.
    [​IMG]

    I thought I'd use the case splitter once a blue moon, but damn I've successfully used it three times! It's paid for itself already. Pressing the crank out the case left side.
    [​IMG]

    I'm also going to send Jesse my 93 crank so he can assemble and true it with a new connecting rod.
    [​IMG]
  6. mtb_man

    mtb_man Unfettered

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    Apr 14, 2009
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    DisTech, congrats on another super-clean build thread.

    Your DR650 thread was a great source of info (along with Lukas' thread) when I got my 650 and this build looks just as useful.

    My local bike wrecker has a forlorn DR350 sitting out the back that I was going to harvest the 18in rear wheel from.

    Maybe I should just take the whole bike (or what's left of it) off his hands? :D
  7. DisTech

    DisTech Been here awhile

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    Thanks mtb_man! The DR350 is under-valued IMO. They have a fair aftermarket (not as good as the DR650). If there are as many DR350's available where you live as there are in the US, then they are a inexpensive, simple, solid, light(er than a DR650), dual sport(able) motorcycle. :thumb
  8. DisTech

    DisTech Been here awhile

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    The case splitter I ordered came in yesterday. So I updated the Case Splitting post three posts back.
  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    Oh this is good. I look foreward to chasing you around on my stock (and clapped out) DR350 when I get home. Can't wait to see where this ends up.:clap
  10. DisTech

    DisTech Been here awhile

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    Sep 3, 2008
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    I bought what I thought was a cylinder head cover but with a description like this, "dr350-dr 350 head=cam rockers 1998" I wasn't sure what I was going to get. I needed that cylinder head cover and for $150 it was worth the gamble. Check out what showed up!

    [​IMG]

    • Head (in good shape)
    • Head bolts
    • Cylinder head cover with rocker covers
    • Cam (in good shape!)
    • Intake
    • Spark plug (not in good shape)

    The cylinder head cover is from a 98 DR350SE so the hole for the manual compression release is not drilled. I hope it's not hard to drill it properly.

    Anyway, I'm psyched! I more or less have all the parts for two complete motors now.
  11. DisTech

    DisTech Been here awhile

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    Thanks, me too! The DR350's are good, but not as good as your Seattle to TDF RR. Keep it coming!
  12. yeroc40

    yeroc40 Long timer

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    Do you need the manual release? That head/cam combo has the auto setup, right?
  13. DisTech

    DisTech Been here awhile

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    It does have the auto-decomp and some say the manual release is not needed, but both my DR350's are kick and I'd like it anyway for clearing flooded after a drop.
  14. LukasM

    LukasM Long timer

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    Great deal! Just as an FIY, I think you are always supposed to keep cover and head together so the surfaces line up perfectly, similar to case halves. But you lucked out anyway.

    If you don't need the case splitter any more and want to sell it, let me know. Can't find one for a reasonable price over here.
  15. jcalis

    jcalis Been here awhile

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    I installed a kick start on a 1996 DR350SE. While it is possible to kick start the bike with the auto-decomp cam, it will be much easier (and start easier) with the manual decomp parts added. The manual release allows you to find the correct starting point (just past TDC) quickly and easily. You still have a good deal of compression build-up to slowly kick through with the auto camshaft.
  16. WB-PDX

    WB-PDX Long timer

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    This thread rocks. :deal
  17. procycle

    procycle Long timer

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    :lurk:lurk:lurk

    I'm running out of popcorn!
    Any new developments?
  18. DisTech

    DisTech Been here awhile

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    WB-PDX, thanks.

    procycle, yes! Finally got the frames over to a local machine shop for some repairs.

    I bent the 93 battery bracket back into shape and had the top part welded back to the frame. I also had the tab for the kickstand switch removed.
    [​IMG]

    A locksmith looked at the column lock, but it turned out the guts were not removable. So I had him drill them out. Not sure if I'm going to repair the lock.
    [​IMG]

    Cracked tube on far side and cracked weld on this side of the 94 have been repaired.
    [​IMG]

    I want to use the Acerbis tank which is for a street frame. So I had the shop fab some street frame tank mounts. They look good, but I just found BikePilot's writeup of his Acerbis tank install and it appears the Acerbis tank doesn't use the stock tank mounts (crap!).
    [​IMG]

    The frames go to Seattle Powder Coating for sand blasting and gloss black powder coating this week.

    I talked to Jesse yesterday and I should be getting the cylinder, head and cranks back in the next couple of weeks. They've been having some family health issues that have been interrupting the work a little. I told them no rush.
  19. DisTech

    DisTech Been here awhile

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    Seattle
    Jesse said one of his other customers was going to swap 5th drive, 5th driven, 6th drive & 6th driven from a 90-93 DR250 into his DR350. The 90-92* DR250 5th gear is supposed to be like the DR350 6th. So you can drop a tooth on the CS sprocket, have nice low 1-4 for the woods and still have a tall 5th & 6th gear for the street. That sounds like a pretty freakin sweet dual sport to me!

    I looked at a few parts fiches and it looks like the part numbers have been superseded so they are all the same numbers now between the DR250 and DR350. Might not be able to buy those parts new anymore. I searched advrider, thumpertalk and maximum-suzuki and did not find any info on this mod.

    Has anyone heard of this?
  20. RandyM

    RandyM Less talk, More ride

    Joined:
    Jun 9, 2007
    Oddometer:
    940
    Location:
    Grass Valley, Ca
    I have a project to fix up a DR250s, so I'm keeping and eye on this thread for ideas.

    Reguarding transmission gear swap, I have not done it. However it looks like the DR250S has a wider range than the other models.

    Here are the transmission gear ratios according to the Clymer manual

    Edit-> Only the 1990, 1991, and 1992 DR250S (Street) versions have the wide ratio transmission.

    <TABLE border=1>
    <TBODY><TR><TD>Gear Ratio</TD><TD>Dr250</TD><TD>Dr250s</TD><TD>Dr350</TD><TD>Dr350s</TD></TR>
    <TR><TD>1st</TD><TD>29/12 (2.416)</TD><TD>29/12 (2.416)</< td><TD>29/12 (2.416)</< td>

    <TD>29/12 (2.416)</< td>

    </TD><TR><TD>2nd</TD><TD>26/15 (1.733) </TD><TD>26/15 (1.733) </TD><TD>26/15 (1.733) </TD><TD>26/15 (1.733) </TD></TR>
    <TR><TD>3rd</TD><TD>24/18 (1.333) </TD><TD>23/18 (1.277) </TD><TD>24/18 (1.333)</TD><TD>24/18 (1.333)</TD></TR>
    <TR><TD>4th</TD><TD>20/18 (1.111) </TD><TD>21/21 (1.000) </TD><TD>20/18 (1.111)</TD><TD>20/18 (1.111)</TD></TR>
    <TR><TD>5th</TD><TD>20/21 (0.962) </TD><TD>19/23 (0.826) </FONT.< td><TD>20/21 (0.962) </TD><TD>20/21 (0.962) </TD></TR>
    <TR><TD>6th</TD><TD>19/23 (0.826) </TD><TD>17/24 (0.708) </TD><TD>19/23 (0.826) </TD><TD>19/23 (0.826) </TD></TR>
    <TR><TD>Final Reduction</TD><TD>49/13 (3.769) </TD><TD>48/13 (3.692) </TD><TD>47/14 (3.357) </TD><TD>43/14 (3.071) </TD></TR>


    </TABLE>

    Hopefully the formatting comes out right on everyones PC (or mac).