Dan's carbs, cams, ignition discussion

[dan filipi]

So I've gone through the carbs, swapped out #2 which had some passage problems which were buggered up by a prior owner, I buggered them further to "fix it" way back when but that carb is now out of the picture with a good #2 carb.

Rack is back on the bike and running.

It cold started without a choke thanks to the accelerator pump juicing it.
While cold I was getting a few spits occasionally, mostly just off idle like before.
I sync'd it again this morning after finally getting the vacuum gauges to calibrate, had to really force the calibration screws on 2 of them to get it.

It accelerates nearly instant. Much of that is due to the C5 ignition because it accelerated quicker like this before I pulled the carbs even when #2 was flodding. An improvement I'm certain of came from this ignition.

If I sync all 4 within 1/2-1" vacuum of each other it idles ok but "sounds" out of sync with a repetitive "clunk, clunk" in time with cylinder firing. Not loud but loud enough to know it's not right.
If I "tweak" the left bank out of sync by 2-3" vacuum it sounds much better. Acceleration and drop down to idle is still very good.

I have 1200 cams in it which was an experiment to see how it would do torque wise.
Way back when I first put them in I was getting over 200 lbs. compression on the right bank and 165-170 lbs. on the left bank. It has since dropped. I need to check it again when it cools off a bit.

I'm thinking because of this compression oddity something with those cams have thrown left to right banks "off" enough to cause me sync problems.
It also seems to be loading up some at idle after idling for 5 minutes or so. A couple quick revs clears it.
Seems flodding related but not sure.

I had found when I first put the 1200 cams in the spit back into the carbs was more frequent so I'm going to put the early 1000 cams back in. When I ran these cams it ran sweet.
Then go from there.

 

[dan filipi]

So compression is 150 on left side, 190 on right side.
I've still got a problem with #2 flodding. Sprayed gas when I cranked with plug out and plug is sooty black.
Learned a lesson here. When I was bench testing the floats and adjusting them, I should have drained the bowls and let them fill a few times to make sure the needles were closing off every time.

 

[dan filipi]

Ran the carbs dry and tapped on #2 bowl.
Seems to have stopped the flodding for now but I think this belief on the forums that reusing old Honda needles and seats being ok is wrong.

Not sure what I want to do right now.
Strange I'm having so much trouble with the #2 carb. Maybe I'm missing something.

Part of me wants to put it back together and leave it, the other part has a hard time leaving it like this.

 

[dan filipi]

Float drop. There's no spec for that in the manuals.

Does anyone know what the spec is?

 

[mcgovern61]

dan filipi » Sun Sep 15, 2013 12:36 pm[/url]":1694pow3]
Ran the carbs dry and tapped on #2 bowl.
Seems to have stopped the flodding for now but I think this belief on the forums that reusing old Honda needles and seats being ok is wrong.

Not sure what I want to do right now.
Strange I'm having so much trouble with the #2 carb. Maybe I'm missing something.

Part of me wants to put it back together and leave it, the other part has a hard time leaving it like this.

Dan, if you remember when I had my carbs done a few years back, they still leaked. I had taken them apart and thought I had cleaned the needle tips and seats well. Back together and they leaked again! I ended up pulling them 3 times and with a magnifying glass took a closer look and saw that the cleaning wasn't as good as it seemed. I ended up with heavy emeroy cloth that I use for cleaning copper pipes and dragging the needle tips across them numerous times until I could see clean black on the tips. (Took a lot longer than I ever would have imagined.) Then I checked the seats and found the same thing.

 

[Ansimp]

Great advice Gerry :good:

 

[Ansimp]

Also Dan make sure that there are no ridges in the rubber tip of the needle, it needs to be a nice cone shape with no indentation from the seating point.

 

[dan filipi]

Well the only reliable way I feel to get this stock rack running as it should is to start replacing parts so rather than dump money into them I'm going to start putting the single carb assembly together.
I've decided this after finding out I've got vacuum leaks at at least 2 throttle shafts.
I already have a manifold and a carb.
I can build this up for much less money than just Honda needles and seats and will require very little maintenance.

 

[C5Performance]

Dan, I want to share a little of what you and I discussed on the phone a week ago.
This is loosely related to your issues, but is some of the ideas you and I shared with each other (in general):


When cleaning carbs, it is my believe that you must now "wipe" surfaces clean. Spraying them no longer gets the residue off, so needles still leak.

I always checked for leaking needle/seats by either using a low pressure "pop off" tool or verifying actual fuel level using an adapter tool that screws into the drain plug and allows you to see the actual fuel level through a glass tube held next to the carb.

These were accepted methods to verify the float was adjusted correctly. I am not fond of the float tools based on my own experiences. If you use the tool, but your needle leaks even a little bit, you are still going to be too rich, and pull your hair out chasing other issues.

One more thing...if a needle passes the leak test, rotate it 90 degrees and test it again. If it leaks now, you have an "off center" tip, probably from aftermarket needles or badly worn factory needles. Replace it...there is no other good solution for this problem.

Dan...please continue (sorry for interrupting).

 

[Steve83]

I believe leaking throttle and choke shafts are the cause of so many issues with these 30+ year-old carbs. I have 4 racks, and every one has play in the shafts. I may try the single carb approach myself, and I'm hoping to get a C5 iggy system soon so I can finally install the new engine in the '83.

Just waiting for the money tree to bloom!!!

 

[dan filipi]

Throttle shafts creating a lean condition, especially an uneven mixture between cylinders.
I'm also going to blame the spitting on this since it would spit mostly out of the rear carbs which are under the most force from the linkage.
Slop in the linkage from left bank to right bank, I'm seeing some of that also.

Spit btw is almost gone.

 

[dan filipi]

Cold startup this morning at 61 degrees needed choke.
This rack has never choked well.
When I pull it all the way on, it runs up to high rpm as it should, but when pushing it off slowly it doesn't drop slowly in rpm like it should. Instead rpm will fluctuate widely then rpms will drop off suddenly.
All very unstable so I have to play with the choke til it warms up.
Spitting comes on more under partial choke.

This morning after warm-up, idle rpm is lower than it was last night.
This rack is very tempermental.

 

[joedrum]

sucking air dan while cold

 

[dan filipi]

joedrum » Mon Sep 16, 2013 7:41 am[/url]":306i05im]
sucking air dan while cold

Yep that's my conclusion also, through the throttle shafts.

 

[C5Performance]

dan filipi » Mon Sep 16, 2013 10:16 am[/url]":d8cmvf17]

joedrum » Mon Sep 16, 2013 7:41 am[/url]":d8cmvf17]
sucking air dan while cold

Yep that's my conclusion also, through the throttle shafts.

Ditto, classic lean condition. On these Wing carbs, do you use carb cleaner sprayed around the shafts to find the air leak, or doesn't it work on these carbs?

 

[dan filipi]

C5Performance » Mon Sep 16, 2013 8:39 pm[/url]":2a4ed7de]

dan filipi » Mon Sep 16, 2013 10:16 am[/url]":2a4ed7de]

joedrum » Mon Sep 16, 2013 7:41 am[/url]":2a4ed7de]
sucking air dan while cold

Yep that's my conclusion also, through the throttle shafts.

Ditto, classic lean condition. On these Wing carbs, do you use carb cleaner sprayed around the shafts to find the air leak, or doesn't it work on these carbs?

I used ether, works better.

 

[C5Performance]

me too. I didnt think you Southern Cal guys even knew about starting fluid...lol.

We use it all the time for finding intake boot leaks. Thats something i havent seen mentioned on this forum yet...must not be a big issue.
That certainly could cause the popping in the carbs when cold!

 

[slabghost]

better to use wd40 to find leaks. Carb cleaners can destroy seals and create more leaks.

 

[mcgovern61]

dan filipi » Mon Sep 16, 2013 10:48 pm[/url]":2b5mti4j]
I used ether, works better.

Ssshhhhh.......we cannot say "ether" around here in NJ. There are still some Detroit Diesel engines around here that got addicted to ether for cold starting and we were never able to get them off of it! Spray some ether into the air around here and those engines will sneak right up on you! :ahem: :hihihi:

 

[Steve83]

Happy ether everyone! :whistling: