Viola: One Good Carb

Prepping the K1 carb to test it on Viola's running engine.  Found the K1's valve pin to be sticking, so I replaced it with the one from the "B" carb.  Had to reset the float height afterwards (19.5), but with that done, she seemed to be in good working order with no leaks.

For reference: the K1 now has B's float valve and seat but kept the better gasket.  Thus B now has K1's seat and valve (but same old gasket).

Roxy: Sizzling!

After Wednesday's ride, noticed that oil was leaking from the intake cover again.  Also, water would sizzle on the fins of the head, which I'd read was a sure sign of an overheating engine.  A lean mixture can cause overheating, and it seemed probable that switching back to stock jets had leaned things out too much.

I was hoping for an easy fix, so I just swapped out the stock jets with the silver ones that were in the bike originally.  So now I have the two silver jets in the "C" carb.

She started up cold on one kick after the swap, but wouldn't idle until I dialed in the air screw.  It's now only 7/8 turn out!

Rode Balboa again today, and was worried when I saw the oil leaking again on my way back.  I thought the oil leak was another symptom of the overheating.  But after getting back to the garage, I found that water wouldn't sizzle anymore.  The head was definitely much cooler.

The oil leak is still worrying.  I wonder if the overheating may have distorted the rubber or somehow caused it to loosen up.  I'll just try tightening things up first.

So now it looks like the silver jets are larger than the stock 85/35.  I just ordered some micro drill bits so I can figure out exactly what size they really are.  You find the largest drill bit that fits through, then you measure it with a caliper.

Roxy: Idle Problem Fixed! (sort of)

Hallelujah, she runs!  But I cheated a bit in that I just swapped out the carb with Viola's carb (labeled CS90C), which I'd already cleaned.  She started up and ran like butter.  Actually had a better, lower purring sound than with the old carb for some reason.  Idled strong for 5 minutes with no signs of hesitation, and it was a warm day so I think the running rich issue is gone.

I suppose I'd still like to figure out what's wrong with the newer carb, but first I'll have to figure out how to remove the stuck float pin.


First thing I did since the engine was cold was to check valve clearances.  Happy to see they were .002" on both intake and exhaust.  Also learned from the forum that the reason the PO probably added the breather tube was to accommodate a bigger cylinder or higher RPM.  Since there's a piston in the old parts bin from the PO, I wonder if the cylinder has been bored out.  We'll find out eventually.

Beautifully clean alternator compared to Viola's.

Then did a compression test for the first time.  Again, thrilled to see that I was getting 120 on a cold engine, especially since I was worried about an oil leak into the cylinder.  Odometer at 17,571.

Noticed there was this hole in the bottom of the muffler, though it seemed like someone put it there on purpose.  Another PO mod to increase breathing?

Also took the opportunity to switch to the new shorter filter (Visu-Filter Mini) that came in the mail today.  Much easier to squeeze between carb and petcock, and doesn't kink the line.

And finally everything installed.  Whew.  She idled and revved smoothly, but I'll have to take her on the road to really make sure everything's sorted.

Keyster Carb Rebuild Kit

Photo reference.  Everything you get in a Keyster kit.  Fourteen pieces (if you count everything on the float set as one thing).

So far I've used:

1. Bowl gasket (in Roxy's "C" carb)
2. Throttle screw spring (in Roxy's "C" carb)

But also added back a throttle screw spring from eBay I'd bought awhile back.