HELP ! cracks in cylinder 1973 175

[gooey]

I was cleaning up the Cyl on my 1973 175 today t prepare for what was to be a simple hone / piston fitting ( standard size)  ... when all of a sudden I noticed a crack on the cylinder near the intake manifold ....



 I guess I am faced with soome choices here .... 1st ... has anyone seen and sucessfully corrected this problem ??



2nd .. does anyone have a cyl that would clean at about 2.499 - 2.501 so I could use the pistoon I have ( cheap is an issue here .... this is a long term project ... )



 3rd ... does anyone have a cylinder that i could clean at around .020 over and, subsequently,, I would have a new Wiseco piston std. size for sale ??



 I am going to try to display pix of my problem here,, if that doesnt work,, e mail me and I will show you the affected area if you think you can offer help or just good advice !  Thanx !

http://www.myglobalwebsite.com/sinfulscents/cylinder.JPG>



 HELP ! ! ! ! thanx again ... you guys really know a bunch about these things ... any help will be greatly appreciated





1973 Jackpiner 175,          my  "real" name is Mark McGrew, my friends call me Gooey,, Please,, call me Gooey!

[dave hussey]

Wow, I wonder what caused that.. excessive thermal expansion of the cast iron sleeve? I've never seen that happen before. One way to repair it would be to have the sleeve removed, then the cylinder tungsten arc welded, rebored, then relined.
 But the GOOD news is you could probably run it like that with no ill effect, provided the cast iron sleeve is not cracked too, and is not loose in the cylinder, i.e., can't rotate. It will not move up and down since the head will keep it in place. Good luck!
Dave H.

[gooey]

Yes,, dave ,, I agree to some extent ... I suppose the ??best?? news of all was that this malady caused me to further investigate the overall engine condition ... the part of this that bothered me the most was that the crack seems to be running along the cast insert,, and there are signs that it is also cracking at the opposite manifold bolt holes ....



 I began looking further into the engine in this bike after that,, as it came to me with the piston out and the top end just loose on the eng ... the inside of the piston dome is more full of what appears to be carbon than any I have EVER seen ... almost completely full to the pin area !  UNBELIEVABLE ! i had simply tossed the piston aside,, and never looked ... Then,,, looking at the crank throws ... on harleys they were the flywheels ... are they known as that here too ?? anyway,,, they show what appears to be some pretty substantial scoring,, and someone befor me filled the crankcase with what appears to be engine oil,, i san only presume to dislove or minimize junk formation ...



I am really disappointed,, as this bike has a lot of things that point to the fact that it was probably a pretty low hour machine,, and probably a "never-raced" bike also ... and i thought,, maybe,, even though proper storage had been a low priority for the previous owner,, maybe there was a diamond in the rough here ...



 I learned a long time ago,, when building custom cars and bikes,, to analyze pieces and make the necesssary repairs as it comes apart,, then reassembly is less full of surprises !



 Anyway,,, these things together have caused me to abandon my Penton project ... those who have noticed my posts have seen that I was teetering on that since the aquisition,,, it is pretty rough ... but I think the best news to come out of all this is that this bike will now serve to help other Pentons come back to life,,and will allow me to concentrate on my other project,, and eventually seek out another Penton project with a little more knoowledge next time !  so it is truly serving a fine purpose indeed !



 need any Jackpiner parts

 

[TGTech]

I've not seen cracks where you are describing them, but those older 175 cylinders, if you ran the piston too loose for too long, would crack the cylinder skirts. We used to use a bronze repair rod with the TIG welder, and weld them up successfully.

[Mike Lenz]

GOOEY  SAW YOUR SEAT ON EBAY BUT WAS TOO LATE. IM INTERESTED.  ALSO LOOKING FOR A FRONT NUMBER PLATE MOUNT,AIRBOX COVER,EXHAUST HEAT GUARD AND 64.45 PISTON. MY EMAIL ADR IS [email protected]. HOPE TO HEAR FROM YOU.