73 XLCH belt drive information? ? ? ? ?

[payebra87]

Hey Gang.

Picked up a 73 xlch from under a house here in Australia, it was a deceased estate so information on the bike was limited.
It had been sitting for at least 12 years.

the bike looks to be in great nic, the usual bumps and scratches, some fixed case damage from behind the primary, looks like somebody rebuilt the bike either early 2000's or late 90s.

the bike starts and runs fine, after some electrical issues, though the clutch wasnt disengaging, upon removing the primary, there was a small amount of oil, and to my surprise a Primo belt drive? has anybody had any experience with these belt drives? was the oil in the primary just from wet sumping? cause I would imagine a belt drive would be a dry sump? has anybody got any information on these? the bike needs new friction plates? would I be running the stock plates?

Some information on this exact setup was varied, so any information would be greatly appreciated.

https://ibb.co/rMQbv97

[WillSCB]

Not familiar with the Primo for sporties, but I can tell you that without major modifications, the Ironhead sporties all shared fluids between the transmission and primary, so a dry primary was not an option. Seems to me I heard someone (maybe Dragstews, as he has a lot of information stored in his head about old iron) that the primary belts designed for ironheads were designed to run in oil.

[Dragstews]

That be a ghost from Christmas past ...



Don't think nobody has made a belt drive for the Ironheads in a Coon's age ...

Back when, I have installed a few, do recall that they required non-detergent oil for lube..
The belt, over time, would break down if other lube was used...

I have spoke with the owner of Karata (Jim) about making them again..
Said he would if he had a hundred orders ... In other words .. He would do a run of em if he had them sold ....

[payebra87]

So,

Would they run in a wet sump?, with the stock friction/steel clutch plates ?

[Dragstews]

Yes ...
... Use non-detergent oil ...

[TriNortchopz]

Bit of info here, wet belt, non-detergent oil...

Ironhead Belt Drive Primary
http://xlforum.net/forums/showthread.php?t=2021283

http://xlforum.net/forums/showthread.php?t=1711661

http://xlforum.net/forums/showthread.php?t=2010280

Do you know about 'The Chopper Shed' in Willunga, SA? Kinda in your neighborhood, check with Prof (Andrew Offe), been building chops down there for about 60 years, can find him here too: Choppers Australia, https://www.facebook.com/groups/6720...group_activity

These guys are showing a 8mm 117T primary belt for a 1973 Sportster...don't know if it is real though: https://riveraprimo.us/collections/sportster-1973

[farmall]

I have spoke with the owner of Karata (Jim) about making them again..

Were they worth it for racing to ditch the primary chain, cover and hassle at the track?

Sportsters don't have primary issues since they're unit engines unlike the long, loud, leaky and loose older HD designs which begat belt drive conversions in the first place. I have one and it worked OK but that engine has sat for many moons and when I repaint the bike it's getting a chain since roadside failure without warning on a part I can't easily swap (and for which I've no spare belt) will suck.

I might look into replacement belts since it's a Sunday ride and belts have drastically improved. Of course automakers don't run wet belts (and only run timing belts at all to save production costs, fuck the owner when the car is past warranty, double fuck if it's an interference engine) because there's no intelligent reason to run them.