Roxy II: Carb Swap

 So after the first shakedown run where she couldn't hold idle once warmed up, decided to swap over to the Keihin CS90C (#1).  

Had the total golden touch today.  The carb swap went smoothly (nice to have the looped extra length of fuel line) and she started right up and ran with no issues.

Then ran the kill switch between the points wire and the coil and that worked a treat.  Ran the black/red wires along ridge behind the air filter and zip tied it into the holes for the stock air box.  Used the cloth electrical tape to tidy it up.

New brake cable went in.  The nodule was a bit too tall to fit the lever, but shaved it down just a bit and then it went in no problem.

Finally, padded the inside rim of the headlight with more cloth tape to get rid of the rattle.

Four jobs that could have gone either way but all ended up smooth as butter and everything worked!  Love days like this...

 

 

Roxy: Stymied Left and Right

Getting stymied from every angle today.

Detaching the switches and getting the old handlebars off went smoothly.

Put on the new black bars and was looking for a comfortable position, though never quite felt 100% right.

Went to cut off the left side and after doing way more turns with the Ridgid than usual, realized that the metal was way too thick for the cutter!  Was already bottoming out against the tool before it had cut all the way through.

Left that to simmer and went to start the bike using the new throttle cable and setup and she would not hold idle!  Classic symptoms of being way too rich: had to dial out the idle and air screw way, way out just to barely keep her running.

So bizarre since really nothing on the carb should have changed as I'd only swapped in a different cable.  So tried swapping back to the old cable to test and still had the same issue.  The Sheng had been running fine just the day before!

Saw heavy white vapor coming out of the throttle cap and air intake side whenever the engine died, again confirming a rich mix.

 

 

Carb Audit

Sorting and auditing carbs.  Found they actually fit nicely into the new Husky cantilever box.

Was able to strip down one of the perished carbs for parts, including swapping over the choke to a more complete one (which is a bit of a finicky job).

Keihin Carb: New Studs

Seeing if we can rescue the CS90 Keihin (#2) with new studs and plenty of loctite.  Could have sworn I tried this the last time and it didn't hold, but too much time has passed and now I don't see why it shouldn't work!

Big Carb Day

Spent all day unboxing, inspecting, and cleaning the 2 new eBay Keihins.

One was missing the choke gate, but otherwise ok.  The other had a very thick coating of old gas but seemed to clean up ok.

Probably the case that I'll be able to make a single good carb out of the lot of them somehow.

Ultrasonic got a good workout.  Had to do the Pine-Sol dip on the really dirty one, but that worked a treat.

Red: Back to Keihin Carb

Had the brilliant idea to use the offset Keihin in Red.  Got all the way to bolting it on then realized exactly why I'd never done it before: fuel inlet is on the wrong side.

But since I'd cut a new DIY gasket for it already, I was able to put that into the E05 that had been leaking a just reinstall it.

Couldn't get her started right away.  Seems to be very fussy about screw settings.

Final air screw setting is 3/4 out and plenty of throttle screw.  This setting works once warm.

Needs choke to cold start but then have to shut off choke almost immediately.

Red: Carb Shuffle Continued

How many times can I possibly swap carbs?  Found that the Keihin E05 was leaking gas from the bowl gasket (which explains why it was empty every time I'd switch the petcock on - should have realized that in the first place).

So had to swap for the Sheng #2.  However, it had the exact same problem as always of having a rough idle and a big time stumble as you roll on throttle.

Tried to tune it while idling but never could find a better setting.

Red: Carb Mystery Cont.

Opened up Red's Keihin (K1 E05) to figure out the float issue.  Some of the custom gasket material had separated and left residue.  Cleaned that off and jiggle the floats a bit.

Reassembled and no more overflow.

Red: Carb Issues Cont.

After riding a few days ago, came down to find that Red would not hold idle.  Classic symptoms of an air leak.

Found that the stud bolt was just turning and not tightening.  Swapped it out for a regular bolt.  After that, held a very rough idle and needed a lot of throttle screw to keep it going. 

As a test swapped Ivy's Keihin (K1 EO5) with Red's (CS90C). 

Red idled ok but floats were stuck and gas came pouring out the overflow tube. 

Red filter very dirty.  Is it possible that having filled the tank to its highest level in awhile, it loosened a lot of rust and debris that found it's way into the carb and clogged the jets?

Red: Carb Swap Cont.

Swap out the Keihin CS90C for the Sheng #1.

Red: Keihin Carb Solve

Well, figured out where the air leak on the Keihin was coming from.  As I went to unbolt it from the intake, found that the stud bolt was completely loose.  Looks like it had stripped threads in the carb mounting and was not cinching down at all.

Swapped over to the Sheng Way #1 and was able to get her to run fine - though still seems to have that same high idle / runs rich issue that the Shengs seem to have.

But at least she's running again...

Red: Roxy Carb Saves the Day

First checked the throttle cap and saw that the ferrule had come off the housing.  Could that have been causing the issue by letting in extra air somehow?

After fixing and tightening that up, started the engine and it would not hold idle at all, no matter how dialed in the air screw was.  So the throttle cap was indeed affecting it somehow.

Then did what I had planned to do anyway, which was to swap that Sheng Way out entirely for the carb just pulled off Roxy (CS90C).  It would have the extra benefit of keeping the vintage Keihin in good running order.

Swapped it out (which meant it joined its original intake, also pulled from Roxy).  Started her up, and she ran like a champ.

Upstairs, pulled the Sheng apart to find that familiar white residue on the idle jet.  And even after two rounds in the ultrasonic, it looked like the big hole was jammed up (couldn't see daylight through it at all).

So knowing all this, it must have happened this way:

1. When I swapped Sheng #1 for Sheng #2, I must have disturbed the ferrule and created that air leak.  That would explain the racing idle that was not fixed even when I swapped back to Sheng #1 as a test.  It also explains why adding the intake gaskets didn't help.
2. The clogged slow jet in Sheng #1 also explains why it always needed so much air screw to run at all.
3. When I fixed the ferrule today, it stopped the air leak, but the air leak was the only thing actually allowing the carb to run at idle at all.  With the air leak gone, the clogged slow jet came into effect.

Also swapped out old taillight bulbs with LED on both Roxy and Ivy.  (Ruiandsion 1157 LED, $11 Amazon)

Red: Idle Issues Continued

Thought that if an air leak was the issue, then I'd swap out the intake for the one I just pulled off of Roxy.

Did that and idle seemed better, though still rough.

Moved the needle back to the middle position.

Red: Epic Bad to Worse

Started with the easy job of swapping out the Left Cover (again).  This time for a new and very clean eBay one.  Went back to the cork-rubber gasket.

Then decided to swap out the Sheng Way carb #1 for the recently cleaned #2.  Swapped it over, went to start and no joy.  Engine would race and then die.  Could not hold steady idle. 

Felt like an air leak.  So decided to add the missing gasket from intake to carb that had been missing this whole time.  Stock gasket was a bad fit for some reason, so ended up cutting a new one from the Fel-Pro pack.  After cutting one, decided to cut a second and put it on both sides of the insulator.

Tried it again and no joy.

Removed the intake from the head to check the gasket there - and there wasn't one!  Could have sworn it had one all this time.  Thought that was bound to be the solve, but after adding a stock gasket, it was the same issue.

So moved the needle down to second from bottom but still very rough idle.