850 MkIIA Mild Rebuild

Top End rebuild and cleanup of my 73 850 MkIIA recently completed.
New .020 oversize JE pistons from MAP, new rings. The engine was smoking before the top end rebuild, but was probable guides and seals. While it was down, new pistons, bore and rings.
MAP "Black Diamond" valves and "Nascar 45" guides, new seals on intakes.
Shimed rockers to locate closer to the valve centers. New rocker spindles.
Rebuilt carbs. They were sleeved by Lund a while ago, still tight.
New rocker oil feed line
Added a Reed Valve to the breather (Yamaha 650)
Lapped head to cylinder, new copper gasket.
New Aluminum rims and S/S spokes, from Buchanan
K81's (now 18" on rear)
Suzuki GSXR front disk, Suzuki RG500 Caliper. Now it Stops!
New Barnett clutch (the original plates were from a 750, now corrected).
Maintenance items (sprockets, cables, chain, bulbs, etc)
This bike is original paint, as far as the tank and side covers. Fenders are original.
Mufflers replace a few years ago with stainless steel, I don't remember the vendor
Here are a few pics (if I get the upload correct):

Very Nice!

Indeed, very nice, that is also a good looking front brake.

Jean

We need to know more about that front brake setup.

Looks like a crotch rocket rear caliper and a front floating rotor.

bwolfie said:

Looks like a crotch rocket rear caliper and a front floating rotor.

Click to expand...

Looks like an RG500 caliper and a GSX disc :lol:

Looks like the disc has been re-drilled to the Norton hub and has an aluminium centering spigot/disc to cover the old holes put on the out side

Very elegant Gnolan. Yep, tell more about the brake.

Sweet!!

Thats a fair old brake! Lets hope the dampers are up to the job!! :roll:
www.lansdowne-engineering.com

Yes, Cheesy is correct. Drilled the Suzuki rotor to fit the Norton hole pattern. The aluminum cover centers the rotor on the hub and covers the original holes.
Caliper is from the right front of a 86 RG500, it was small enough to fit without modifying the fender bracket.
I made both the centering cover and caliper bracket.
Master cylinder is the 13mm conversion from Old Britts.
Braided line is sourced locally (Earl's of Indy).

Thanks for all the compliments.

George

gnolan said:

Yes, Cheesy is correct. Drilled the Suzuki rotor to fit the Norton hole pattern. The aluminum cover centers the rotor on the hub and covers the original holes.
Caliper is from the right front of a 86 RG500, it was small enough to fit without modifying the fender bracket.
I made both the centering cover and caliper bracket.
Master cylinder is the 13mm conversion from Old Britts.
Braided line is sourced locally (Earl's of Indy).

Thanks for all the compliments.

George

Click to expand...

Have you got a CNC mill? that bracket is very difficult to make manually.

Lovely scooter. Engine running well?

gnolan said:

Here are a few pics (if I get the upload correct)

Click to expand...

Ummmmmm....

Yeah, you got the upload correct.

VERY correct.

This is what all new member posts should look like!

That is a sexy, sexy bike. Love it!

grandpaul said:

gnolan said:

Here are a few pics (if I get the upload correct)

Click to expand...

Yeah, you got the upload correct.

VERY correct.

Click to expand...

Well, the moderator did step in to correct a minor error in the first photo code :wink:

I don't have a CNC mill at home, but we have about 40 of them at work.

The engine runs pretty well, still need to sort out a little wiring issue. I rode home in the rain the other day and it died. I think I need new plug wires & caps.

George

George,

That is a very nice set up, I have done a lot of the same things to my 850, except the flash front disc and caliper set up. But I am envious! Now you can get out and enjoy the bike. Would like to know how the reed valve breather goes? I might be wrong, but I would say your bike is a MK11 from what I gather the M11A was a euro model with a plastic air cleaner and maybe black cap silencers in lieu of peeshooters. But I like the mk11's better, more pure and raw, that is what mine is!

Cheers Richard

You may be right about the MKII vs MKIIA, I'm not sure what the differences are. This bike had the rounded covers over the ends of the swingarm like a MKIII, but the swingarm spindle is held in place by (1) screw like an earlier one. I made new covers with o-ring seals because I couldn't keep the rounded plugs from leaking. Also, they are a true pain to remove.
Does anyone know the s/n's of MKII's vs MKIIA ?

George