Author Topic: it250k motor finally together  (Read 2871 times)

0 Members and 1 Guest are viewing this topic.

Offline ITDOG

  • C-Grade
  • **
  • Posts: 66
    • View Profile
it250k motor finally together
« on: April 12, 2015, 09:56:55 pm »


Hopefully got it right the first time........now to take the scungy carby apart

Offline OverTheHill

  • Legend
  • *****
  • Posts: 801
    • View Profile
Re: it250k motor finally together
« Reply #1 on: April 12, 2015, 10:31:52 pm »
had an it250k motor that was cracked just up from the base & over a large area--most of one side [RH side by memory. Was still in one piece but un-useable without surgery. Was a common problem back in the day with lot's of ideas as to 'why' i.e. frame flex on jumping--loose engine mounts--etc, or all of the above. Think people used to leave the head steady off in the end. I did wonder if a head steady with rubber bushes set into both bolt holes of the frame or the steady plate--say honda sprocket rubbers, bonded steel rubber type might help give some support but slight flex as well. Even the YZ250/360A had that on the rear top engine mount supposedly [i thought] due to frame flex. Maybe i'm wrong. Anyway my IT250K has a YZ465H motor in--that fixed it lol. Do love the 250K motor though, bullet proof, 6 speed & great to ride. Sorry for the essay, more picks when finished please. I see the DG pipe--got one from 'dirt overstock' a few years back for our yz490k & was a terrible fit out of the box which was disappointing. Thanks.

Offline OverTheHill

  • Legend
  • *****
  • Posts: 801
    • View Profile
Re: it250k motor finally together
« Reply #2 on: April 12, 2015, 10:37:15 pm »
by the way--i should've said your motor looks great & looks worksy with the bead blasted cylinder & head.

Offline ITDOG

  • C-Grade
  • **
  • Posts: 66
    • View Profile
Re: it250k motor finally together
« Reply #3 on: April 12, 2015, 11:06:30 pm »
yep this barrel has been welded ...so I will not be using the head stay brackets!!....sprocket side case was smashed from a jumped chain, but replaced that half from my donor 250H...selector shaft so bent it needed to be cut to remove. Selector drum would not fit in easily on reassembly....turned out to be bent also!!!!.....donor bike again.
On a positive it was on the original bore and was pretty much complete...but extremely rough

Offline OverTheHill

  • Legend
  • *****
  • Posts: 801
    • View Profile
Re: it250k motor finally together
« Reply #4 on: April 14, 2015, 09:02:36 am »
[I think] the K has a 68mm bore. Earlier It's & YZ's a had 70mm bore. Long way from needing to go to one of those pistons if still standard [providing gudgeon height & ring pegs a right] Big Bore!!. Did wonder if a YZ cylinder from a G or an H would fit the IT cases & was going to check base gaskets but never did in the end as think i flagged that idea due to the stroke difference 68x68 as opposed to 70x64, then again in hind sight a bit more stroke might help.