MV750 Soviet Flathead Rebuild

Discussion in 'Old's Cool' started by RomaDakota, Mar 4, 2010.

  1. Possumhopper

    Possumhopper Urinal Pilot

    Joined:
    Aug 24, 2008
    Oddometer:
    36
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    Home on the Range
    Yummy. Now that tank badge will serve a purpose.
    #81
  2. mark883

    mark883 and the mysterians

    Joined:
    Feb 16, 2007
    Oddometer:
    1,612
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    Buckeyeland
    Lousy Cheapass Chinese Crap gaskets.....

    My left hand cyl head gasket blew out, its doing the old psst psst psst.

    I can see a small crack in the asbestos? layer between the copper.

    Brand new. I know I didn't do it, either.

    What are the good gaskets to use on one of these POSes?

    And its so nice and warm outside right now. :bluduh
    #82
  3. arcticIndian

    arcticIndian indian rider

    Joined:
    Oct 9, 2006
    Oddometer:
    239
    Location:
    near the arctic
    I'm using the chinese headgaskets, no problems so far.
    Does it leak at the same place where the old headgasket was destroyed?
    #83
  4. mark883

    mark883 and the mysterians

    Joined:
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    After replacing the cheapass chinese gasket with the Kruschev era aluminum gasket, I got the bike running, and prompty.... began to cuss the right hand carb, which was now puking gas all over the exhaust pipe. Cheapass Chinese imitation Keihin carbs! Later that day, I cleaned up the float valve, and rode it around the neighborhood, trying out my newly hooked up and functioning head and taillights. Whereupon it promptly killed the battery, and couldn't be restarted. So, I called Dad's tow service, who pulled me back to the barn behind his suburban.

    A 6v Battery Tender seems to have rejuvinated the battery. Nothing worse than a cheap walmart battery charger. You might as well just burn your money.

    Soooooooo.... today, I decide to gamble all the chips, and put Dad's towing service on standby. The local harley dealer is having hotdog day, so I decide to take the commie bike, where it can leak oil with the best of 'em. Well, believe it or not, the valiant little KMZ made it to the harley shop, while the operator froze his face off in the clear, sunny but cold and windy northwest ohio day. The KMZ's incontinanace was amazingly well controlled, only leaking a bit from the oil pan, a spot from the back of the tranny, and three drops from the final drive, which seems to be self leveling even when filled according to the dipstick.

    The fearless KMZ made it all the way home, for a total kilometerage for the day of about 65. Top speed achieved today was about 45mph indicated, which was accompanied by lots of valve noise and whining of gears. I think it could go faster with a higher rear gear, but then the brakes must be considered. It really seems to favor about 40mph for a comfortable top speed. The engine seems to pull really pretty well, for an old flathead with pretty loose pistons. Overall, a successful day!
    #84
  5. Possumhopper

    Possumhopper Urinal Pilot

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    Updates?
    #85
  6. RomaDakota

    RomaDakota Illuminatus!

    Joined:
    May 15, 2006
    Oddometer:
    1,580
    Location:
    Goldilocks Zone
    Thanks Possum - been busy selling some British junk :evil
    Now for more junk...
    The cylinders - a portion of the IRAN that I dreaded. They are heavy, cumbersome and needed cleaning even before wrenching.
    <img src="http://farm5.static.flickr.com/4028/4498225971_7079f6d709_b.jpg" width="534" height="762">
    Started by soaking them in solvent for a bit then allowing the solvent to run down my arms and drip off my elbows into my jacket as I take them over to the bench. A bit of wire brushing, then repeat – ahhhh the constant smell of solvent that lingers… Started on the valves, checked guides for wear then lapped them. Another cleaning cycle then time for a light cylinder hone as I have new rings. The books are vague and no spec given for the ring gap; quite a slow and questionable read for me as my books are in Russian. Another read over and plenty of data on ring-2-pistion gap (even a table) but still no luck on ring end gap. So I used the 0.004” per inch of bore formula etc. Man I do not see how anyone uses the british standard for measuring. Anyaway, all fine if not slightly bigger – no worries.
    Time for the valve installation.
    <img src="http://farm5.static.flickr.com/4035/4498729644_20b4a1b4d0_o.jpg" width="762" height="534">
    The PO had installed springs without the fiber washer at the base of the spring assembly. Trimmed a few for use with my gasket punches.
    <img src="http://farm5.static.flickr.com/4052/4498715554_b654191765_b.jpg" width="534" height="762">
    Valves installed and all cleaned ready for installation; same was done with other cylinder. Boy these things are H E A V Y!! Here is a good shot and one can certainly see were the "side valve" name comes from. Wiped a bit of oil on the surfaces to fend of corrosion.
    I had already cleaned the pistons when I measured for new rings prior to ordering. Installed and lubed the rings then moved onto cleaning the wrist pin area on the rods. Nothing to spectacular or unique to this portion of the rebuild. More tedium as I cleaned and re-installed all of the cylinder studs which really took more time than I would have ever imagined.
    I should have taken some pics of the tappets during install but I was lazy. Something a bit unique and I blew it off. Sorry ‘bout that.
    <img src="http://farm3.static.flickr.com/2697/4498720940_f578c68a17_b.jpg" width="534" height="762">
    Here is a snap of the piston installed along with the tappets in place. Note how they are secured in place by the specially shaped block in between them.
    Tomorrow is wrench, booze and lies night, hope to install the cylinders. I’ll have the &#1092;&#1086;&#1090;&#1086;&#1072;&#1087;&#1087;&#1072;&#1088;&#1072;&#1090; (fotoapparat) handy.
    #86
  7. mark883

    mark883 and the mysterians

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    Looking good, Roma.

    This winter I may want to do a ring/valve job on mine. This is helpful.

    Of course, I may need to do an overbore......
    #87
  8. RomaDakota

    RomaDakota Illuminatus!

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    Some wrenching was accomplished on hang-night.
    <img src="http://farm5.static.flickr.com/4027/4501493703_4f9a9ea8f5_b.jpg" width="534" height="762">
    “Were are my cylinders?”

    Still amazed at the weight of the cylinders, I decided to weigh one
    <img src="http://farm5.static.flickr.com/4048/4502799146_17f1821456_b.jpg" width="534" height="762">
    Wow – a 17 pounder! Including valves and springs.

    With a helper holding the cylinder and adding some horizontal pressure, I compressed the rings with my fingers and we worked the cylinders into place. The bottom of the cylinder barrel is beveled to assist with this step.
    <img src="http://farm5.static.flickr.com/4034/4503317996_e5ed9da2a4_b.jpg" width="534" height="762">
    Cylinders installed.

    Last bit of progress on the evening was installing the heads. I put the ignition cover in place just for the photo.
    <img src="http://farm5.static.flickr.com/4002/4502819810_e4c1636fcd_b.jpg" width="762" height="534">

    Next will be the clutch pack then the ignition.
    #88
  9. YZman

    YZman Bouncing off Trees

    Joined:
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    1,126
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    Meeeechigan
    Are those cylinders (fins) and heads as crusty as they apear to be? They are just beging for a bead blasting.

    And yes I know its a sickness, but that ignition cover is just begging to be polished.


    Either way... loving the build. I aint never seen a motor like that before :clap
    #89
  10. RomaDakota

    RomaDakota Illuminatus!

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    Back at it after vacation and other airhead projects :)
    Time for the clutch
    [​IMG]
    Flywheel ready to accept the springs

    [​IMG]
    Springs installed

    [​IMG]
    Discs and plates installed and ready for screws.

    [​IMG]
    Ready to peen the screws

    [​IMG]
    I also used loctite on the screws for overkill. Done for now

    Time to install the engine, hopefully later this week.
    #90
  11. RomaDakota

    RomaDakota Illuminatus!

    Joined:
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    With the clutch done, it was time to install the engine in the frame. I also test fitted the tranny but it will have to come back out to fit the clutch actuating rod and other pieces. Here is a pic from earlier in the week.

    [​IMG]

    Yesterday it was raining again and seemed like a good day to spend a decent amount of time on the MV. My Father is in town so I had a helping hand.
    Quite a bit of wrangling took place to get the tranny installed with the actuating pieces in place an properly lined up. The tip if the actuating rod is square and fits into a square hole in the pressure plate. To make certain it was inserted into the hole we made a tool out of a butt splice and a screw so I could turn the rod after the tranny was in place and feel it slide into the hole.

    [​IMG]
    Note all of the tools used...

    Time to install the driveshaft which requires removing the final drive. This will also allow phasing all of the shafts.

    [​IMG]

    Installed the ignition, carbs and tank. What now... Time to kick it...
    Kicked at bit and had a few puffs, then I remembered I had held off torquing the heads to spec. With that done, she fired on the second kick! Cylinder temps monitored; both were within 10 degrees on one another, no strange sounds - good news!
    <object type="application/x-shockwave-flash" width="400" height="300" data="http://www.flickr.com/apps/video/stewart.swf?v=71377" classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"> <param name="flashvars" value="intl_lang=en-us&photo_secret=2714a0d8f1&photo_id=4611065590"></param> <param name="movie" value="http://www.flickr.com/apps/video/stewart.swf?v=71377"></param> <param name="bgcolor" value="#000000"></param> <param name="allowFullScreen" value="true"></param><embed type="application/x-shockwave-flash" src="http://www.flickr.com/apps/video/stewart.swf?v=71377" bgcolor="#000000" allowfullscreen="true" flashvars="intl_lang=en-us&photo_secret=2714a0d8f1&photo_id=4611065590" height="300" width="400"></embed></object>

    Now a multitude of details to attend to before the ride...
    #91
  12. Reposado1800

    Reposado1800 Juicy J fan!

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    Dec 8, 2006
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    5,806
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    5th and Main
    Sooo nice.
    #92
  13. RomaDakota

    RomaDakota Illuminatus!

    Joined:
    May 15, 2006
    Oddometer:
    1,580
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    Goldilocks Zone
    It is getting there. The clutch actuating lever was homemade when I received the bike. Seemed to work OK but was ugly and had a non-standard hook-up for the clutch cable.
    [​IMG]
    I sourced a standard clutch lever and installed. However the standard clutch cable mount was missing. The original one is quite a pain as it is really only two semi-flat pieces of stock and the cable is sandwiched between them. You really have to tighten everything to tight and the cable still slips sometimes. With the part missing and fact that I don’t like the design anyway, I decided to fab me a cable mount.
    Start with a closely sized roll-pin (need a gap to get the cable through) and some flat stock. I had to drill out the roll-pin just a bit to be able to fit the metal portion of the cable inside. Cut to length then drilled and tapped for a set screw; the mounting point with the flat stock. A quick weld and a test fit - nice.
    [​IMG]
    Some paint then installed - I’ll get a proper set screw at some point.
    [​IMG]
    With the clutch done, it was time for a short test ride! Ran great! Back in the garage for some tilt alignment then back for another test ride - pulls nicely and I would say has as much get-up-and-go as my OHV Dnepr.

    Current state - the race look :) Still with incorrect wheels.
    [​IMG]
    [​IMG]
    Next will be fitting the sidecar body and getting the correct wheels installed...
    #93
  14. wrigh003

    wrigh003 n00b

    Joined:
    May 11, 2010
    Oddometer:
    6
    Too cool. Good to see the practical application of the "if it's worth doing, it's worth doing right" theory.

    Good job, looking forward to seeing more pictures and tales of the rebuild/upgrade/fix process.
    #94
  15. RomaDakota

    RomaDakota Illuminatus!

    Joined:
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    Took some tinkering to get final details under control
    - brake lights working
    - u-joints serviced
    - wheels swapped
    etc

    Now deemed roadworthy. Here are a couple comparison shots from when I first bought the bike home and now over a year later.
    Then
    [​IMG]

    Now
    [​IMG]

    Then
    [​IMG]

    Now
    [​IMG]
    Funny how all the work is not reflected in the photos :lol3

    Just had to drive it up a dirt pile...
    [​IMG]

    I plan to ride it for a while and let the parts do their final meshing. Then I have a couple projects I want to complete. First the final drive locking device installation and two wheels (sidecar and spare) need to be swapped for correct type (this will require re-stringing a couple of hubs and rims I have laying around).

    Surprises so far - how easy this thing starts! Damn, probably just cursed myself...
    #95
  16. jellycow

    jellycow Back on track!

    Joined:
    May 29, 2005
    Oddometer:
    1,046
    Location:
    South side of the Netherlands
    Damn, it still looks like a well used dirty old bike. Well done! Because that's the way I prefer them to look.
    #96
  17. camit34-1

    camit34-1 Been here awhile

    Joined:
    May 23, 2010
    Oddometer:
    101
    Location:
    Colorado
    X2!!! Great work!
    #97
  18. MeRide

    MeRide Me like bikes!

    Joined:
    Jul 28, 2008
    Oddometer:
    1,160
    Location:
    NH, USA
    I love the patina on that bike! Please don't paint it. :thumb

    What's going on with it as of late? Would love a ride report and/or details of how it rides, shifts, brakes, etc.
    #98
  19. afcope

    afcope dabbler

    Joined:
    Oct 22, 2010
    Oddometer:
    16
    Location:
    Southeast
    I know this thread has been dormant for a while, but I am suffering through a long Central European winter and some of the small issues with my bike are beginning to beg for some attention so I have been searching for other KMZ owners. I really appreciate the detail of your thread. It is really hard to find well documented SV information. That leads to my real question, what reference books, or other information, do you use? I have a '67 K750 and I am struggling to find reliable info. I have the Russian side valve motorcycle book, but it is all in Russian. So, the tables and illustrations are great, but it is nothing great. Anyway, great build, and I really enjoy seeing other vintage bikes that are actually used! Here's mine:

    Attached Files:

    #99
  20. uraldog

    uraldog vagabond

    Joined:
    Nov 1, 2007
    Oddometer:
    405
    Location:
    west of the rock
    lots of info and help here -- CossackPower (b-Cozz) for M-72, Ural Dnepr & Izh Motorcycles and Sidecars