Ironhead So you don't want to split those cases?

[hcrashster]

Used motors contain lots of surprises. This sprocket shaft came out of an 1980 motor that ran and had no issues. Split the cases if you have any doubt.$70.00 worth of gaskets and some effort,[ or enjoyment IMHO] may save you, and your motor. Besides the shaft, 2 cam cover bushings had the shoulders ground down to the cover. I don't like these kind of discoveries but I definitely don't like a bomb with the fuse lit between my legs!

[85mm]

OUCH! Good catch.

[thessler]

hcrashster
Wow I wish I had your confidence. I have been spending lots of time trying to diagnose a knock. Fixed the biggest one, loose fly weight on the timing advance. But there is still something there it's small but I still hear it. Just afraid to dismantle the whole thing and not find the problem. This may be the inspiration I need to just do it.
Tom

[hcrashster]

I remember your thread. Between this forum and your service manual you have all the info. you need to fix that knock. I remember thinking: You might have some problems there. The advance weights self destructing leading to full advance at all RPM ranges. As the spark fires way to early, { When the piston and rod are on the compression stroke } the entire rotating assembly is getting hammered. Remember the piston has to ascend to top dead center, then descend on the power stroke. Early spark forces piston and rod down while the flywheel, is thru rotation, forcing it up. Bearings don't survive this for long. Tear it down and look. Take pictures, write notes, and put parts, by assemblies, into marked plastic bags. Take it step by step. It really is fun, I mean it.

[gunterjaeger]

Sheesh! Glad you had the agates to go in. Its just a biiitch without the tools and experience to crack the cases. When you put her all together and the SOB is leaking or something and you have to go all the way back......well, Im sure thats where a lot of good Ironheads found new owners sitting all pretty in boxes

[ezmerf]

If you do spilit them you may think of sealing the inside the cases.Some believe the cases are porous and need sealing.Most all we did was use the best sealant out at the time,but some on here someone informed me it was a bad practice and you should shot peen them.Anyway you choose this would be the time to do this.

[hcrashster]

I clean and prep aluminum like this. Hose or sink and Dawn dishwashing liquid, and a stiff brush. Repeat till clean. This type of hands on action gives you an excellent time to look for cracks and casting boogers, old repairs etc. Any steel present gets WD-40 after being exposed to water. Cases are then taken to a local Tranny shop for glass beading. Once home they get cleaned again and again. On the mating halves I use a large smoothing file and red roloks. Go very lightly, don't dig a trench, aluminum is SOFT. Clean again. If any threads were found during cleaning, such as timing hole or drains or for the bolt ons that look iffy after thread chasing, I retap or Helicoil. Basically this is blueprinting the case. These cases are the weak point of the Sportster, give them a fighting chance.

[60weight]

Good time to have that drain hole under the flywheels welded up to if You have one.

[rivethog]

When you go back together with the crank, check to make sure that the new sprocket shaft doesn't "bottom out" on the face of the flywheel before the taper is fully seated. When the sprocket shaft is torqued down you should be able to get at least a .010" feeler gauge between the lip and the flywheel. If you can't, remove the sprocket shaft and have the flywheel faced at the sprocket shaft hole.

[fergerburger]

the coating that is painted on the inside of Harley cases is glyptal. HD did this on sportster cases but I do not know what years....my 1960 had red glyptal from the factory....not sure if HD used glyptal but it is the same stuff.

before the IH gods here say I'm full of it....I was told HD coated cases by an retired Harley assembly worker in Milwaukee. Maybe he was full of it.