80 Iron rebuild

[N-gin]

Where is a good place to get pistons and cylinders cheap. This needs to be a budget. What is happening is I'm fixing this for my Dad's Vietnam friend, he is giving it to his kid to start riding. This bike has been sitting for a while and I looked at the cylinders inside and they are rusty. I did get it to run but it eats oil.
I will be splitting the cases as well so is there a coating to put on the cases so they don't weep oil?
Is there anything to look out for while I have it apart?
Thanks for the helps and advise.

[Panzer]

If you ran it and the cylinders were rusted, then the rings were fried.....it's no wonder it drinks oil.
Try honing the cylinders and mic the end result.
If in specs, try new rings and put it back together.
Just my .02

[JW113]

 

Bust the rust free with a ball hone or even just scuff it down with red Scotchbrite pads, and mic the jugs and pistons. Sportys will run fine and in fact like pistons a bit on the loose side, since the jugs & heads run so damn hot. Maybe all you need is a set of rings?

The thing that works for me is either Hylomar or Permatex #2. DO NOT use silicone RTV. Oil seems to break it loose and every time I've used it, leak. It's also a PITA to get cleaned up again without damaging the aluminum mating parts, unlike the other two mentioned.

This will be your friend for a project like this:  Kirk Kelly at Sporty Specialties.  http://sportyspecialties.com

Good luck with it!

-JW

[N-gin]

OK this winter I'm going to tear into it.

Is there a primer for the cases?
I remember a red die if I'm not mistaken that seals the aluminum from the inside

[Panzer]

No, no primer, just clean the surfaces with carb. cleaner and let dry.
If you don't want silicone, might want to try Loctite red gasket maker.
I don't like it because it dries had and a bitch to scrape off but, it does seal.
I never had a problem with clear silicone, you might want to rethink it.

[JW113]

Agree that a lot of people use silicone rubber to seal the cases, just saying I've had some problems with it, and to me it's not a sure thing every time. The problem comes from the fact that in the AMF years, the aluminum they were using wasn't the greatest, and that they cranked up production and didn't stay on top of quality meant the casting process got a little sloppy. The result is castings were prone to hydrogen porosity. Silicon will stick very well (too well if you ask me) to clean and oil free metal. If the metal has any porosity, oil has gotten in and all the chemical cleaning in the world won't get it back out. You have to bake it out at high temperature, which almost nobody does. The silicone will not stick to oil, and thus can cause an oil leak later. The other well know issue with silicone RTV is that the stuff that squeezes out from the seams can break off and end up in places you'd rather it not.

This is what I like about Hylomar, it never dries and will seal even if the surface is slightly oily. But the best part is that if you have to service it again, Hylomar wipes right off with acetone. Silicone rubber you have to scrape off, and if it's gotten a good bite, you can damage the metal mating surfaces trying to dig it off. Nothing I hate more than trying to scrape off RTV or stuck on gaskets. Which is why I now use Hylomar on gaskets as well, as they peel right off no matter how long they been on.

Speaking of porosity, I had a weep in the transmission of my '80 XL which I could not track down to any gasket or seam. The solution was to clean the hell out of the inside of the case and paint the inside with red Glyptal enamel. So those cases had enough porosity for the oil to ooze right through the aluminum casting.

JMHO,

-JW

[turboprop]

OK this winter I'm going to tear into it.

Is there a primer for the cases?
I remember a red die if I'm not mistaken that seals the aluminum from the inside

Take a look at having the pores in the casting vacuum sealed. I just sent some cases to a place in Maryland that specializes in sealing metal. The bill was $136 for a batch. While I only had a few cases to do, I could have sent up to 150 pounds for the same cost.

For convenience they are located right down the road from Zippers Performance.

http://metaseal.com/services

[Racepres]

1104 3-Bond for case halves...
Never used anything else...tho I heard Yamabond is the same "Potty mouth"!

[turboprop]

Yamabond #4

[N-gin]

Just an update
There is a museum in NewYork, and they had a new iron head. And since the Ironhead I was working on had a bad trans and needed 2500 in engine work to get it right we decided to get the museum engine. It looks great pics don't do it justice. I looked into the cylinders and it was never fired up.
It is really dusty, but I'm not complaining. It also came with new carb, starter, and generator. Even though the bike is a 80 and this engine is a 81, wich has newer style gen, and start. It fits like a glove in the frame.

[JW113]

N-gin, sounds like you must have gotten an offer you couldn't refuse on that museum motor. $2500 seems kinda steep for an ironhead overhaul though. Was that including the trans? And what was wrong with the trans, if I might ask?

Have to say, alternator on the ironhead was a nice improvement.

-JW

[N-gin]

The cases got welded around the trans.
Well they didn't resurface the case halves with a bridge port or other machine the just sanded it down. Well they sanded it too much and when the case halves are put together there was a 1/16 gap. So i guess they just tightened it even more to make the halves meet. Well this crushed the tolerances in the trans. The gears are chipped the bearings are purple. All bad...
it was 500 just to repair and resurface the cases.
no trans work was included in billing

[JW113]

Jeezz-zuss fricken krist. It never fails to amaze me what's out there that passes itself off as "mechanic". Doctors are supposed to take an oath about not doing more harm than good. Be nice if they made mechanics do the same.

Sounds like the score on the museum motor is the ticket, dude. Congrats!

-JW

[Brrrap]

 

[Hossamania]

Who the hell finds a motor in a museum, and then gets them to sell it, besides? Great find, congrats.

[Burnout]

Museum bike = not assembled with usable parts

[Hossamania]

Museum bike = not assembled with usable parts

How so? Depends on the bike and museum, doesn't it?

[N-gin]

This is just an engine. Everything looks complete on it. Hell it even came with all the oil lines.
I put it in the frame and everything bolted in nicely. It was a tight fit for sure. I'll be wrenching on it here and there in-between jobs.
There was a Gary Bang sticker on it. Maybe rebuilt¿
Anyways I found the add on EBay and the engine was located at Motorcyclepedia museum in NewYork, Newburg.
They had a few engines there including Flathead,Knuckle, Pan from what I was told.

[wreck74]

Welded case's without a-line boreing will cause the bearings to burn up and turn blue. The heat it takes to weld aluminum warps everything, have it a-line bored before you assemble it.