Topic: Final hurdle to a full carb rebuild

[Nortstudio]

I have been completely rebuilding a new rack of 087a carbs that I finally found for my 1976 550k. Got everything clean and back together, and 2 days ago, had the slides lined up with just a hair of light shining thru.

I then got the spring mechanism back on, and somehow between 2 days ago and now, my slides are up between 1/8-1/4". I can seem to get the sync screws to lower them - they are at a point where they are all the way down. Idle screw is out, and not touching the plate.



I'm wondering if it's related to the fact that my throttle butterfly does not seem within spec distance of the stopper.  I can't push the butterfly any further toward the ground to make the slides get lower.



Any thoughts?

[Duanob]

Are you measuring the cut out side or the long side. I believe you measure the long side (the engine side) of the slide. I use a 1/16" drill bit to bench sync so I get use of the my throttle idle screw.

[Nortstudio]

OK, let's just get this straight.

A) I'm an idiot!
B) let's make that B too. I'm an idiot!

Sorry folks, I think the fumes from the Works in the tank got to my brain, despite taking safety precautions.

I checked it from the back side, it's at 1/16" bit height now. I know TT and Dave500 (thanks Dave!) like the slight light measurement. Maybe I'll try this, and then try that. I'm open.

My idle screw is still not in too far, but it is engaged. Is that OK? 

Also, I moved the eccentric screw (what will they think of next?) so the butterfly is off the stop by about 2mm, which is spec.

Thanks folks.

[Nortstudio]

Well, I finally got the carbs back on the bike.  Decided at the last minute to leave off the in-line filters.  Playing it fast and loose!

Of course, I fire it up with some fresh gas, and the carb #2 starts pouring from the overflow tube!!!!  #1 did a little too, but not as bad...

Figuring it's the float needle stuck.  I hope that's all it is.  I may swap it for the one in my old rack, because those were in decent shape.  Try, try again,  Tomorrow is another day.

Thanks for all the help.

Scott

[Duanob]

FWIW whenever I have the rack ready to put back on the bike I kinda jiggle it a bit to make sure the floats aren't stuck in one position.

I got one of the clear tube float check tools that works great. Not only to check to see how fast the bowl fills and valve shuts off but to make sure all floats are set the same.

hope you get that thing running soon! 

[Nortstudio]

Thanks duanob,

I went to the garage this morning, knocked on the side of the bowls with a rubber hammer, and bingo, no more leak.

Unfortunately, I have ripped carb boots, so I threw on a set of emgo pods I had lying around.  I know, sacrilege, but I figured it would keep anything major out of the intake while I source some new boots. I also figured I would be pulling the carbs (just my luck), and man is it easy with pods . Of course, makes you have to pull them all the time, so which came first, chicken or...

Problem now is: pipe #4 is running cold.  I also have a rpm hang now and again.  Not sure opif the hang is strictly from the pod, but the hang may be. Or maybe hanging because of sticky slide???

I didn't have time to get into the carbs again, had to swap out brake pads to make it safe to even test it around the block.  No squeal!!! That's something I guess.

Where did you get this clear float tool?

[Duanob]

Got it from TAS through ebay. $14 well spent.

I had a hanging idle when I first put my carbs back on the bike this past weekend. After a vac sync they acted normal again. My number 2 carb was waaaaay off with the others.

[Nortstudio]

I figure that might be the ticket.  I'll sync them as soon as I can.

Quick question.  I plan on doing the whole 3000 mile tuneup.  Should I hold off on cam chain, valves, new points etc until I have this sync'd and straightened around?

Thanks,

Scott

[Nortstudio]

Just ordered one of those float checkers.  Thanks for the tip.

[Duanob]

I figure that might be the ticket.  I'll sync them as soon as I can.

Quick question.  I plan on doing the whole 3000 mile tuneup.  Should I hold off on cam chain, valves, new points etc until I have this sync'd and straightened around?

Thanks,

Scott

Other way around my friend. Do the timing stuff first, carb sync absolutely last.

[Tintop]

+1  Make sure all the mechanicals are in spec 1st.

[Nortstudio]

Cool, thanks guys. 

That's the way I did it before, but at that point, I hadn't completely rebuilt the carbs.  Wasnt sure if that changes things.  I'm on it.  Hopefully this does the trick.

Appreciate it. 

[Duanob]

Cool, thanks guys. 

That's the way I did it before, but at that point, I hadn't completely rebuilt the carbs.  Wasnt sure if that changes things.  I'm on it.  Hopefully this does the trick.

Appreciate it.

Keep us posted.

[Nortstudio]

Uh oh. Just realized the new points/condensers I got are Daiachi.

I've read some horror stories about these. When I did the 3000 mile tuneup in the fall,, I never swapped points or condensers. So hopefully these will still be better than what I have now.....

[Nortstudio]

Cylinder #3 exhaust side rapper cover is stripped. Its the one thats semi-blocked by the tach cable port.  Any tricks?

[flybox1]

Uh oh. Just realized the new points/condensers I got are Daiachi.

I've read some horror stories about these. When I did the 3000 mile tuneup in the fall,, I never swapped points or condensers. So hopefully these will still be better than what I have now.....

for the Daiichi points, you can make them work. Hondaman did a writeup on how to correctly tune them. tweaks are needed.  gap is different than stock. just do a search for Daiichi points.
-or- you might get lucky like i did and find a used/complete points plate on CL or eeebay($15), and poach those OEM ND points and condensers.
as for your hanging idle, be sure all your airbox-carb-engine boots are soft, fitted all the way on, and properly secured.
and +1 to what Duanob posted. Carb vac sync is the last step 

[Nortstudio]

Ok, either I'm WAY off, or I'm VERY lucky. I did the static timing with the 12v light. I may have had it rigged up wrong or backwards, because the light was on the whole time, and then would go off immediately when I approached the F mark. I had hot and ground wires on the two light posts, on the other end the hot on the battery hot and ground on the frame ground. couldn't find my damn notes, so...

I went with "lucky" and continued like that. Got the static lined up nice - without modifying the plate. Used 014" as the points gap. Moved on to dynamic timing after letting the bike warm up a bit to see if I could get the RPM hang to go away. It was mellow, so I gave it a shot.

At 3000 RPM, I was just about spot on, both slightly advanced (by maybe the width of one marker line. Both the same.

Called it a day, because it seems to have just hit 100 degrees, 90% humidity. And the dog needs a walk

[Nortstudio]

Almost forgot.  IDLE HANG:

Right now I can't check the carb boots, because I temporarily have pods on there - while I wait for new ones from a forum member.  If you think this is the sole reason for the idle hang, please say so. I DO NOT plan on keeping the pods, so no love lost there.

Also, cylinder #4 is still running cold.  Not sure if that would cause idle hang?  When I slapped the timing light on it, it's showing spark, so I'm going to have to get back into the carbs.

In case it wasn't just the pods or cylinder #4:

I checked the manifold boots, and they all seem tight and in good condition. I tightened a couple clamps, hoped that was it.  Still hung a bit.  I had put in new intake o-rings too, when I had the carbs off. The new ones were perfectly round, where as the ones previously in there were flat. Was this from pressure, or are they supposed to be flat to begin with (like a tank cap gasket)

I sprayed a healthy amount of WD-40 around all the seams to see if the RPM would fluctuate. Nothing happened. I fiddled with the idle screw, got it to where it really only drops slower than I'd like, not hanging for terribly long. But still not right.

Maybe the air mixture screws?  I have them at stock 1.5 out. But maybe with all this pod air, they need to be in, and might help the mix?

 

[flybox1]

Maybe the air mixture screws?  I have them at stock 1.5 out. But maybe with all this pod air, they need to be in, and might help the mix?

Yeah, i would say so. stock screw setting + pods will be really lean at idle.
if you've done a good bench sync of your carbs, and pretty certain that your slide heights are all identical, take off your pods while the bike is not running and look to see that all of your slides are closing in unision as you open the throttle and let is snap closed.  a slide might be hanging and slowly closing with the help of the return spring.  recheck all passages, emulsion tubes and jets, and float heights if you're carbs come off again.  i know...its a pain.
if everything looks spot on, i'd wait to dig into the hanging idle issue and your cold #4 until you get your stock airbox/boots on there.

[Nortstudio]

Thanks flybox. I just posted another question about the slow jet while you were posting here. I have them off the bike again to check number 4. Nothing seems obviously out of whack.

I ran some carb spray. Will double check everything else too.

Is there some type of lube used to make sure slides don't stick?

[Nortstudio]

Float level is good. Sprayed out entire carb, seems good. slides snap back in unison, without any of them hanging.

Made sure all slide level start at the same point. They are all aligned together. My only concern is that with no idle screw applied, I can only get the slides to lower to about the diameter of a 3/32" drill bit. After that, the sync screw don't make it close any further. Is this normal?

Thanks for all the help and putting up with so many annoying questions folks.

[Duanob]

3/32" is fine. It's somewhere between 1/16" and 1/8".

Aint the interwebs great? You got two yocals from the Seattle area helping out a guy in Brooklyn, NYC! At least I hope we're helping.

[Nortstudio]

No question you're helping!!!  Thanks so much.

I'm just kicking myself for missing it to begin with.

Now I just need to figure out if my slides are not closing as far as they should.....

New carb boots on the way, should have shipped today!

[flybox1]

glad you finally got your c-hair thru that jet    it might just help out with #4.

[Nortstudio]

Thanks. The "scientific" 1/2 C hair seemed to do the trick. Can't remember what the gauge of the original wire was - but of course this was just one strand from within that.

The fact that these thing run (or not) on such small variances never ceases to amaze me!

Any thoughts on the maximum closure on te slide?  Does it seem like that is too little?  Should I be able to close it all the way down to nothing if I wanted (not that I would) or is there a finite amount of adjustment downward with the slide?

Of course got the carbs back on the bike - pouring gas like a #$%*. But a couple satisfying blows with a mallet did the trick