Need Help!!!! Engine rebuild in the making. First priority is reliability

Discussion in 'Full Rebuilds' started by Regg1000, May 22, 2020.

  1. Regg1000

    Regg1000 New Member

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    Hello,

    I got a blaster in pretty bad physical shape the the other day for 800 bucks. I would like to start rebuilding my engine. My engine is currently running at 90 psi compression, starts up after several kicks on a cold start, has a hard time idling. I put a new ngk B8ES spark plug, cleaned the carb, put new premium 32:1 gas in it, and a fresh new yamalube. The air screw is turned out 1 1/2. It idles pretty good when the engine is warm. The carb is new, has a 135 main jet, stock pilot. It runs pretty decent, at 90 psi the engine isn't perfect, but its alright. I would like to eventually rebuild the engine. Here's what i have on my list thus far.

    1. Full new top end (cylinder, cylinder head, piston, rings etc)
    2. New Stator
    3. New CDI
    4. TORs delete
    5. New air filter
    6. New FMF pipe

    I understand that you need new jets with this kind of setup. Please let me know what kind of jets i need and also, whether a big bore kit is doable. My first priority is reliability, i do a lot of heavy dirt riding. Therefore i would like a setup that wouldn't sacrifice reliability. All advice is helpful. Thank you.

    Thank you!!!!!
     
  2. Slydog

    Slydog Member Technician

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    For a rebuild there is no reason to buy a stator or cdi box.if they were bad your bike would not run. Don't buy one of those cheap kits with cylinder,head,piston,and gaskets. That cost as much as a weisco piston. Most regret it. Bring your cylinder to a machine shop they can measure it and order all parts for you so everything will be correct. Re-use old head.they don't go bad unless something breaks and gets between piston and head. If jetting is correct now? Boring cylinder to next size generally requires no jetting changes.but still needs to be checked to confirm. Leakdown test for airleaks.air leaks can fry a new topend quickly
     
  3. Regg1000

    Regg1000 New Member

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    Ok. Thank you. Also, do you know a websir I can buy a new piston and crank? Or a company I can ship my engine to for boring/porting work? Also, I thought about changing the head for visual appearances. The previous owner had this thing sitting outside, and it’s peeling and rusted. Perhaps powder coating would help?
     
  4. Regg1000

    Regg1000 New Member

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    There’s also an old DG pipe, that I would like to change to an FMF or Toomeys one day. What main and pilot jet is needed for those pipes.
     
  5. Regg1000

    Regg1000 New Member

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    Lastly, after I bore the cylinder. I assume that I would need to resize the piston correct? If so, what size piston do you recommend?
     
  6. Tankbuster

    Tankbuster Member

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    I would call Ken O' Connor racing. He is the," PREMIER Blaster Expert". He is on this site.
     
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  7. Slydog

    Slydog Member Technician

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    Look up ken occoner racing. For the machine work.give him a call. He can supply you all the parts also
     
  8. Larry's Shee

    Larry's Shee Active Member

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    Either your eyes are way worse then mine, or yo don’t have a stock carb. :eek: When you get your “Plan” finalized, then we can help with jetting. Without looking (which you can do) at a website for the pipes mentioned we’re a ship out of water.
    Lots of things you might change.
     

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