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Show us your TransAlp modifications!

Discussion in 'Japanese polycylindered adventure bikes' started by modrover, Apr 13, 2004.

  1. Clem Kevin

    Clem Kevin Nude With Boots

    Joined:
    Aug 17, 2007
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    1,365
    Location:
    Petrolia, CA
    Could someone tell me what the manual states for piston clearance. Just dropped off my cylinders for boring.
  2. 2old2Bbold

    2old2Bbold was 2bold2getold

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    I like to set my motors up pretty tight but .0004" sounds too tight to me. ??? Especially if you're not using oem pistons. After market pistons should have a stated clearance with them.

    [​IMG]
  3. Clem Kevin

    Clem Kevin Nude With Boots

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    Location:
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    Went with OEM. I'll consult the machinist, but he says he prefers to run right. But damn that is TIGHT.
  4. 2old2Bbold

    2old2Bbold was 2bold2getold

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    Agreed, .015" - .002" is my go to. Anything under .001" is pretty tight. Probably need careful break in.
  5. Clem Kevin

    Clem Kevin Nude With Boots

    Joined:
    Aug 17, 2007
    Oddometer:
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    Location:
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    Thanks for the piston clearance info, I appreciate it guys. Cylinders are ready to go.

    Next step is customizing the wiring up front. I'm switching to a Trailtech unit, and wanted to add an extra switch that is hidden for the ignition. I'm inexperienced with electronic schematics, but please help me out here...

    starter.png
    Which of these is actually sending power to the on/off switch on the handlebar, and which one is the starter button? I have my guesses, but I'm just looking to be sure.

    Red/Yellow goes to the starter relay switch
    Black/Red goes to the fuse box (fuse d)
    White/Green goes to the fuse box (fuse b)
    Black/White goes to the CDI unit
    Blue/White goes to the handlebar switches and powers hi/lo (I'm not actually sure what that means).

    Another thing that I'm feeling a little confused about is the lack of ground wires up front. Can I run my own ground wire for powering the trailtech unit, and does it need to return to the battery or can I just use the frame ground points?

    Finally, if anybody else is experienced with this wiring diagram, is the black wire up front just a circuit for everything that's controlled by a switch? I'm assuming it's doing the same job as the brown wire?
    Honda 1989 xl600v transalp wiring Colorized2.jpg
  6. 2old2Bbold

    2old2Bbold was 2bold2getold

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    expand ^^^


    Thanks for the color diagram. :clap
    Clem Kevin likes this.
  7. Skyliner

    Skyliner Adventurer Super Supporter Supporter

    Joined:
    Feb 26, 2010
    Oddometer:
    95
    Location:
    Woodside California
    Why would you guys second guess the Piston Clearance Specs from Honda? I went through all my manuals from 1989 to 2013 and they all call for pretty much 0.0004 - 0.018 with 0.04 as the Service Limit.
  8. 2old2Bbold

    2old2Bbold was 2bold2getold

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    Experience.... 30 years building VW (and other) motors. :dunno
  9. aggrohead

    aggrohead Inside Sucks

    Joined:
    Apr 26, 2010
    Oddometer:
    153
    Location:
    Tri-Cities, WA
    Fuel Capacity question:

    So I was coming home from a long trip (250ish miles), the first of that kind of length I have done with this bike. On the way home I had to switch into reserve going down the highway. Bike started sputtering out like it was losing fuel, but would surge every now and then so I assumed it was just really low on gas.

    I go to fill it up, and it took 3.51 gallons of gas. Everywhere I look says that these bikes have 4.8 gallon tanks with .77 of that being for reserve, so what gives? I should have had another gallon of gas, which would have been enough to get me home, even my buddy I was riding with said "you shouldn't need gas yet!" his bike is a 2016(?) Tiger 800 and has close to the same range and capacity on paper. My tripmeter showed 135 miles, which gives me 38.46 mpg, whereas the week before I filled up and got 49.2. The engine got a little toasty at times on the trip, so I stopped a few times to "check the scenery," but I never let it get into the red, but the temp needle was in the upper 3/4 area if that makes sense.

    So basically my questions are, am I using the reserve wrong or something? Could a vent hose be pinched somewhere? Could the heat that I was riding in have that much impact (but still doesn't explain the 3.51 gallon refill)?

    This is the first bike I have owned that I have done long distance stuff on, so I apologize if these are noob questions. I am just kinda confused here.

    Also here is a pic from the ride! Found this awesome set of switchback fire roads, and I got to try out my new Tusk Pilot bags and some new camping gear.

    IMG-2414.jpg
  10. tag3

    tag3 Doofus

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    Location:
    Inland from the coast of Santa Cruz and Trona.
    135 sounds about right. As soon as I put bags on mileage suffers.
    aggrohead likes this.
  11. Skyliner

    Skyliner Adventurer Super Supporter Supporter

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    You have to be pulling a boat to only get 38 mpg. My TA 750 with cloth bags gets gets 45-46 mpg. My Varadero 1000 gets 33 mpg with cases, top box Passenger and fully loaded.
    aggrohead likes this.
  12. Skyliner

    Skyliner Adventurer Super Supporter Supporter

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    Location:
    Woodside California
    Experience.... Factory Trained Honda Mechanic 1975
    aggrohead and 2old2Bbold like this.
  13. DaleE

    DaleE TransAlp Adv

    Joined:
    Jan 13, 2006
    Oddometer:
    763
    Location:
    Boulder, CO
    Wind, speed, temps and weight all can have a huge impact on mileage. There's a rpm point, around 5000+, where the mileage on mine drops dramatically if held there for a while. If you were trying to keep up with your friend on the hwy, especially if there was a headwind, that mileage isn't out of range. The tank capacity is what it holds, not what you can use. If it's hot, it's also hard for the little vacuum pump Petcock to maintain pressure on a low tank.
    aggrohead likes this.
  14. 2old2Bbold

    2old2Bbold was 2bold2getold

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    So you would set up motors at .0004" (less than 1/2 a thousands inch) piston to cylinder clearance ? Does that work out ok ?
  15. Skyliner

    Skyliner Adventurer Super Supporter Supporter

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    I've never found anyone with that kind of precision machining. But I've definitely had some that were less than 0.001". Now my Wiseco Big Bore High Compression pistons need more space. Even then, Wiseco recommends 0.002". A stock low compression Piston can handle less. Your talking less than a 3" piston.
  16. 2old2Bbold

    2old2Bbold was 2bold2getold

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    I think our experiences are very similar. Most of the piston and cylinder sets I used were .0015" - .002". Honda probably has the expansion rate figured a little better than the German Mahle sets and much better than the Brazilian and Mexican sets, but those piston/ring sets were good for 100k miles even back then.
  17. Skyliner

    Skyliner Adventurer Super Supporter Supporter

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    I don't think Honda would run 0.002" - 0.003" clearances and then say "We'll tell them it was 0.0004" - 0.0018" just to ƒuck with their minds".

    I was just looking at my V-Strom 1000 manual and it says it has a service limit of 0.12" for piston clearance.
  18. 2old2Bbold

    2old2Bbold was 2bold2getold

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    I think they were smart enough to use compatible alloys of piston and cylinder material so the thermal expansions were not detrimental. That sounds like a real art to produce a system that will not bind up at -40f and +120f, especially at those small clearances.
  19. 2old2Bbold

    2old2Bbold was 2bold2getold

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    Guessing that's supposed to be .012".
    .120" might be a little sloppy. :D
    Sorry my technical brain just naturally pics up on silly little details. :dunno
  20. Skyliner

    Skyliner Adventurer Super Supporter Supporter

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    You're Right, Sorry. It was 0.12mm (0.0047") . It was late.
    2old2Bbold likes this.