Yamaha WR250R Mega Thread

Discussion in 'Thumpers' started by Sock Monkey, Apr 7, 2008.

  1. fred flintstone

    fred flintstone Been here awhile

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    That is a great thread, thank you.
  2. ba_

    ba_ Long timer

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    .
  3. Longboardr

    Longboardr Been here awhile

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  4. Crawdaddy

    Crawdaddy Navigate 2 Adventure

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  5. Ed@Ford

    Ed@Ford Long timer

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    Look for hardware stores that have the assortments in "little drawers"...about 50% of the time they will have the washer head style metric in grade 8,8 and 10.8.....usually an M8 will be 13mm hex in the usa...but sometimes you can find M12 hex. Stainless and stock bolts are unrated so they are weaker than an 8.8....I put on 10.9 when I can get them..often times the 8.8 grade have M10 hex....but these are REAL hard to find. Look for such stuff at Tractor supply, ACE, Valu hardware sections...FORGET finding them at Lowes or Home Depot....McMaster Carr is less than 50% having them.

    Oh, yeah...in the little drawers of them, I've never found M8s longer than 60mm
  6. ba_

    ba_ Long timer

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    Thanks

    I found 10.9 in 50mm and 60mm with a 13mm head at ACE. I will try those first.
  7. Ed@Ford

    Ed@Ford Long timer

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    yeah, i went with the M13 hex on a similar job on my KLR.....found m12 hex, but not enough
  8. HardWorkingDog

    HardWorkingDog Harvey Mushman

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    Those stainless steel bolts are OK (pricey), but my solution to finding longer good quality flange head metric bolts is my local Honda car dealership's parts department.

    The local Ace Hardware has metric flange bolts but they are generic Chinese crap with poorly made threads and rough finishes--not something I trust to hold critical loads or look at and feel like :puke1...

    Turns out Honda's parts numbering system for bolts is readily decoded, and they use the same parts numbers for both motorcycles and cars. An 8x55 flange bolt is 95701-0805508. High quality Japanese-made, beautifully formed and spec'd. to meet the strength needed here. Call your nearest Honda car parts department, ask for that number, if they don't have it in stock they'll get it usually the next day. I paid about $1.25 per bolt, well worth it.

    95701 = flange head bolt
    08xxxxx = 8 mm dia.
    xx055xx = 55 mm length
    xxxxx08 = thread pitch??? (less certain about this...)
  9. Ed@Ford

    Ed@Ford Long timer

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    That is a great bit of trivia to decode honda bolt part #
  10. ba_

    ba_ Long timer

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    Calling now. Thanks
  11. DefyInertia

    DefyInertia Saratogian

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    Lots of discussion regarding the pump being cooled by the fuel...

    For those of you that have added a heat shield when installing your aftermarket tanks, what material have you used? Perhaps you have reused the shields that came on the OEM tank? I have some of that tape that is used on HVAC systems that might help...
  12. Old_Crow

    Old_Crow Been here awhile

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  13. NJ-Brett

    NJ-Brett Brett

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    Modern fuel pumps in cars and bikes have the fuel run through the electric motor part of the pump, and the pump itself. The fuel cools and lubes the parts.
    It seems crazy to run gasoline through a DC electric motor, but for some reason, they do not explode.

    Everything I ever looked at had a fuel pressure regulator outside the pump, in some cars its on the fuel rail and excess fuel returns to the gas tank. The pump runs all the time the motor is turning, and runs for a bit with key on to build up pressure. The pump can supply more fuel and pressure then the motor can use at high rpm's, full throttle, cold engine. Once fuel pressure gets past the regulator set point, it pushes the regulator open and fuel returns to the gas tank. Some cars have/had a vacuum assist on the regulator, open the throttle, vacuum goes away, fuel pressure goes up a bit.

    Bikes have the pump and regulator in the gas tank as an assembly.

    Run low/out of gas and there is no fuel to lube and cool the pump and its motor, which has a large amount of plastic in it, and the hot spot is the brushes. They tend to melt their holders.
  14. Gryphon12

    Gryphon12 Long timer

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    It turns out the liquid gasoline isn't really as flamable as we commonly believe. It requires the right percentage of oxygen to burn. The 20.2% oxygen in our atmosphere will do it, so we commonly experience flamability. Toss a lit match in an open pool of gas, and it burns. Do the same with diesel fuel, and you get a wet match. This is why many marine engines are diesel engines. They don't catch fire as easily when bad things happen out on the water, far away from help.

    However, there are lower and upper limits (LEL - lower explosive limit and UEL - upper explosive limit) of oxygen beyond which gasoline won't burn. Too much or too little, and no combustion. (Of course, too high a % oxygen will "burn" all by itself!) A fuel pump emersed in gasoline provides no oxygen, and so the environment is below the LEL. Hence the liquid gasoline can be pumped as an incompressible fluid, and at the same time can be used to transfer heat generated by friction away from the pump, without the danger of "catching fire" in the gas tank.

    Despite this, many race cars use external fuel pumps (outside of the gas tank) for ease of maintenance and replacement. They pump higher volumes at higher pressures and have a correspondingly higher failure rate. External pumps have been tried on motorcycles, but they are usually more hassel than they are worth, given limited space to place them where they can get enough airflow for adequate cooling. The internal configuration is just more compact and easier to keep cool - as long as you don't run it dry (very often?).
  15. NeilW

    NeilW 2-up Adventure Touring

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    Stock tank insulation.
    [​IMG][​IMG]

    Safari tank insulation.
    [​IMG]

    I don't think you could reuse the stock insulation. It probably wouldn't fit well even if you could get it off. I used the foil-backed plastic bubble wrap type and metal-backed tape to hold it on. It's still holding up pretty well after a couple of years of use.

  16. sturgeon

    sturgeon Been here awhile

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    Something like this would also work well.

    http://www.heatshieldproducts.com/p...-fairing-heat-shields/hp-heatshield-mat/76/35

    I've used it to insulate luggage from exhaust heat.
  17. ramz

    ramz Professional Trail Rider

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    Discount Honda Parts
    http://www.discounthondaparts.com

    BOLT, FLANGE (8X55) (95701-08055-08 ) Retail $1.22 Your price $0.99

    Order at the bottom of the year-by-year list
    'Reverse Part Number Lookup'

    They will have 10 or 12mm hex heads, never 13mm.

    :ricky
  18. ba_

    ba_ Long timer

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    I ordered those from service Honda earlier. Should be perfect
  19. Joe Watson

    Joe Watson Long timer

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  20. scoprire

    scoprire Been here awhile

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    I've had good luck getting individual stainless bolts from http://www.desmoparts.com/ High quality bolts, great selection too. He has kits for some bikes, but a separate page for individual sizes.