Restoration noob time: 1978 KE175

Discussion in '2 smokers' started by riiv, Sep 28, 2020.

  1. riiv

    riiv Street Smoker

    Joined:
    Sep 10, 2015
    Oddometer:
    168
    Location:
    Utah
    If people are interested, I will gladly record my adventure on learning everything from scratch with this bike. I record most everything with photos for reference later so I thought why not share them?

    One day, I had the sudden grandiose idea that a street legal 2 stroke would be an amazing commuter. I basically ignored brand new WR250F once I committed to the venture. I don't actually ignore it and gladly still ride it because the desert is my soul. But winter is coming and I want a project(see: money pit) for my perfectionist ways. Besides: restoring something cool!

    The last two stroke I had was an 86 CR500 when I was 15. Boy did I no know how to ride that bike or what that bike was worth(non monetarily speaking.) I've always been 4 stroke everything because longevity, reliability, laziness, blah blah blah whatever excuse you can make. But this time, its the want and need to tear down and feel those scored cylinder walls, listen to the grit in the bearings, clean the grease off of fucking everything, and dream about new life being breathed in to this machine.

    So if you're willing to follow along with my mistakes, outrageous expenditures, and unwillingness to give up, then cool. Cause here she is and I have barely a fucking clue what to do.
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    #1
  2. mikeysduck

    mikeysduck Slow Ride to Nowhere

    Joined:
    Jan 18, 2008
    Oddometer:
    1,097
    Location:
    Acton Ca.
    I'm in.

    I've been thinking about doing the same thing. I'm curious about parts availability. I am sure basic items to "make it run" are available. I want to know about the small bits of rubber and model specific pieces.

    I fancy a Honda MT250. Maybe a Kawasaki, or Suzuki. A Yamaha would be plenty cool, but there are so many out there. I see a hand full of bikes pop up every year. Most have been left outside and qualify as scrap... Money pit. Then I think what will I do with it when it's done?
    #2
  3. aptbldr

    aptbldr easy rider

    Joined:
    Apr 20, 2009
    Oddometer:
    1,578
    Location:
    Upstate South Carolina, USA
    Crankcase seals, bits of rubber, are frequent casualties of time for vintage two-stroke machines.
    If they leak, controlling the combustion mixture is nigh-on impossible.
    Lean-burn conditions and seizeure may result.
    #3
  4. riiv

    riiv Street Smoker

    Joined:
    Sep 10, 2015
    Oddometer:
    168
    Location:
    Utah
    After(if) I finish this I will be looking for an MT250 myself. It was between this and a 1980 TS185. The rotary valve system really intrigued me. I've been surprised at what I can find from warehouses(Rocky Mountain ATV mostly) but eBay has been the golden hour. Not sure I've spend so much money on eBay in the 20 years I've had an account as I have in the last two weeks. The biggest issue I'm facing is there is no information out there. It's all KE100 stuff that gets the limelight with new parts and bolt kits and an aftermarket. That's where the Yamaha's have a huge advantage. So since it's related simply because of the rotary valve, I can extrapolate into this different design on the rebuild. But again, using parts diagrams and search the number on eBay, I have found all but a couple things pop up.

    So I've been curious, will a lean condition with an auto-oiler still damage the bike? Obviously to lean is going to be detrimental but how I've always understood it was the leaner a pre-mix bike is, the more dangerous because less oil in the fuel being pumped through whereas with the auto-oiler it is pumping the same amount of oil, rich or lean. Or is the oil not the actual issue?
    #4
  5. riiv

    riiv Street Smoker

    Joined:
    Sep 10, 2015
    Oddometer:
    168
    Location:
    Utah
    So to start from the beginning, I bought the bike about three weeks ago and picked it up two weeks ago. It's funny how at first something seems so good and then you start digging in and finding out the pieces hacked together out of laziness or necessity. My father bought and picked it up(near him 3 hours away) and I had to wait a week before I even saw it. I hadn't been so excited for something in such a long time.
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    There were grommets and gaskets missing for the air box, but it started it up easy first kick so I was happy. Planned on tear down from the git go so who cared if it huffed dust for a while. Inside of the tank looked good.

    So I ordered everything I need and waited a week and a half before I actually rode it because I wanted it to be right when I took it out. During that time I did the important(I think) initial first steps. Plug reading(super oily like whoa), compression test, and with two spark plug holes, I was able to peer inside the cylinder to get an idea(like what the fuck do I know) what things looked like.
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    I ordered a manual the day I told dad to pick it up. A remanufactored shop manual printed by a guy in New Zealand. Still waiting to this do for it to arrive. Is that a good PSI for the combustion chamber? I'm assuming 100 is probably the minimum for any engine(always guessing) and the scoring on the cylinder wall had me uneasy but whatever. The moment finally came so start it up.

    This was after riding it three or four times around the block trying not to smile when my wife asked me how is it.
    #5
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  6. riiv

    riiv Street Smoker

    Joined:
    Sep 10, 2015
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    168
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    Utah
    So after riding it for a little bit, I pulled the plug and saw that it was lean. I messed with the carb some(still noob at that shit too) and I'm only assuming I need to jet it up. The shifting was very hard to do as well. The shifter wouldn't rebound back to the middle, as if the spring was broken or something. Had to manually move it back with the foot. More on that later.
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    So I took the final initial pictures of the bike as is before pulling the engine. These are for reference for anyone in the future who might find this post. I have requested a couple things from forums and Facebook groups and gotten jack shit for help.
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    Pulled the exhaust and had a looksie up the port and pipe. Yummy.
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    #6
  7. riiv

    riiv Street Smoker

    Joined:
    Sep 10, 2015
    Oddometer:
    168
    Location:
    Utah
    Then got to work yanking the engine and a bunch of other bits out. Gratifying in and of itself.
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    Before pulling the engine I drained the oil and realized the shifter was fine. WTF? Well, I had ordered a magnetic drain bolt from Gold Plug and it was longer than the stock one(was it the stock one?) and with the drain being right below where the shift pin is.....now that the engine is on the table, I can get a better look at what happened. Idiot me and bad information them is what fucking happened. :(
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    Scratched and gouged the shifting pin/rod/whatever pretty decent. Live and learn. I might buy a new one I dont know know. Probably fine.

    On to the head! The part I've been most curious about because it's not the clean up and reinstall bit like everything else. Measuring and machining and fucking math man! I'm not great at math and this is what I want to do for a hobby.:hmmmmmSo any input here would be appreciated. I've ordered vernier calipers, telescoping tools, and uh that's it. Do I need these? Do I need more? Will a machine shop(got a highly recommended one in mind) be able to help me better?
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    #7
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  8. aptbldr

    aptbldr easy rider

    Joined:
    Apr 20, 2009
    Oddometer:
    1,578
    Location:
    Upstate South Carolina, USA
    Before re-sealing, my TS250 Suzuki would start and run fine, except upon constant cruise at 45 or mph for ten minutes the piston would begin to seize-up. Off & on the throtte, stop & go, I couldn't feel it tighten up.
    #8
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  9. RustyStuff

    RustyStuff Long timer Supporter

    Joined:
    Jan 14, 2012
    Oddometer:
    10,801
    Location:
    Crakima,Wa
    Lean makes more heat, heat makes the piston expand. Thus it seizes.
    #9
    riiv likes this.
  10. Foot dragger

    Foot dragger singletracker

    Joined:
    Dec 27, 2006
    Oddometer:
    26,009
    Location:
    chico,just below rag dump(nor-cal)
    If you want a bike that would be of more value when done,the Yamaha would be the thing. The Kawasaki/Suzuki/Honda dual purpose 2 strokes have a little bit of a following.
    The Yamaha's are the ones people look for. Even late model Yamaha enduros,77/78/79 and so on,are sought after. Suzuki's Kawi's not so much.

    The DT175 and 125 seem to have some kind of world wide following. 1980 and 81 are commonly ridden and rebuilt.
    I think Yamaha kept making the DT175 in many parts of the world and may still do so. Oddly there are aftermarket top ends being sold for them.
    Cylinder's/pistons etc.
    #10
  11. Runaway Train

    Runaway Train The Left-Right Tourer

    Joined:
    Aug 9, 2013
    Oddometer:
    519
    Location:
    Ontario, Canada
    Yamaha trials models have all fared well over time too.
    Lots of support for them and perform well in the right hands.
    #11
  12. Euromad

    Euromad Been here awhile

    Joined:
    Feb 16, 2010
    Oddometer:
    544
    Location:
    Lower Slobbovia
    It can still seize- with a leaky crank seal you can't judge how much it's leaking air- plus a nightmare to jet properly. New seals on an old bike are a must- 50 year old rubber.
    #12