Recent content by FirePowerMinis

  1. FirePowerMinis

    Best Head Gasket?

    I use a whetstone on the head and deck, at least. Some 300-ish on a flat counter isn't bad, to see any high spots. Those coated steel gaskets should be fine. Accurate torque on the head?
  2. FirePowerMinis

    Vegas Cart 460cc

    That tight gap ring and the scuffing in the bore almost look like ends butted. Are the ends shiny from rubbing?
  3. FirePowerMinis

    Identify this engine

    The Tecsperts will nail it down, but H25-30 is what it looks to be. Bore and stroke will help.
  4. FirePowerMinis

    Vegas Cart 460cc

    Yes. Define "built a 460". Oil ring expander overlapped instead of butted, head gasket leak to breather passage, compression ring upside down, would be the order of likeliness I'd assign.
  5. FirePowerMinis

    Unknown Clone

    6-8 degree key from your vendor of choice would be fine. Without the key, a quick lapping with toothpaste, Comet, or even actual lapping/grinding compound is wise, then install key. The thinner key with more offset, and the greater chance of a backfire while yanking, can allow shearing. If...
  6. FirePowerMinis

    Unknown Clone

    IMO, For cheap power gains in the governed range, it's tough to beat compression and timing. An advance key would be fine. Thinner head gasket and/or a small chamber head swap. 14cc heads are cheap, and with a few minutes of Dremel work flow more than enough. Racers dislike the alleged...
  7. FirePowerMinis

    Unknown Clone

    This setup?
  8. FirePowerMinis

    Mikuni 12 position adapter.

    I never had an issue with loosening. I'd give it a quick pass over a sheet of sandpaper on the counter top, and a smear of Threebond 1184, and get the screws plenty tight. You may still need/want to slot or enlarge the manifold holes to fine tune the position. I haven't done a QA, but on the...
  9. FirePowerMinis

    Mikuni 12 position adapter.

    Yep, on the Z50 and clone stuff. Watch the countersinks, as some have been too shallow and the attaching screws stuck up above the flange when tight. Also, be sure the screws you thread in to it don't go in too far and jack the engine side away from sealing.
  10. FirePowerMinis

    Vanguard V twin engine modded for minibike

    OP looks to have deleted his Youtube channel and Instagram. Hopefully he gets in to a trade school, vo-tec program, apprenticeship, something, before he gets hurt.
  11. FirePowerMinis

    Vanguard V twin engine modded for minibike

    In my experience, the crank cheeks aren't hardened through. I've spun a bunch on my little 0" Jet. Many seem to be induction/flame hardened at the pin hole, so between that and the interrupted cut, I'd consider as large a diameter center tube as practical. Or,,, hit that B with an angle grinder...
  12. FirePowerMinis

    Tecumseh H50 Stroker

    I usually use a set of these, or a similar set with outward bent tips that I use for port diameter verification.
  13. FirePowerMinis

    decompression valve

    The "Harley" one pictured is cheap chainsaw part, $10-15 for decent ones. The plug type requires a slotted thread area (read thread-chaser) or the oddball unit pictured.
  14. FirePowerMinis

    cooling tins

    A lot will depend on the particular engine, and the application. I'm removing all of that on my street cruiser Tec OHM110 since it's cylinder is upright and the exhaust port is on the side so it gets some cooling. Flatties and slopers may not fare as well, unless turned around and run through a...
  15. FirePowerMinis

    Vanguard V twin engine modded for minibike

    The rod would have to be removed, but the rest is fine, after a static-balance session. Or, one could turn the OD to accept a tube that both cheeks are welded to. Depending on the primary drive gear retention method, it may be possible to replace with a shaft of drill rod or similar. Splines are...
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