Topic: 75 550F (069a carbs) UPDATE***5/29/2012

[Tews19]

I have the above mentioned carbs on my 550F. I use the stock headers and lossa reverse megaphone muffler. Carbs are all stock and popped on deceleration. TwoTired, 550 guru, has been helping me out with it. I bumped the mains to 100 from the original 98s. TT advised me to move to the fourth notch to help with leanness and the deceleration popping.

Carb are off and I found out the shop who cleaned them last summer already had them on the fourth notch. The air mixture screw was 2.5 out. I'm thinking this may have attributed to the leanness. 4th from the bottom to the top leaving one notch left.

Is the 4th notch counting from the bottom up? Or from the top down? It would make sense from the top down as then it would be set at factory specs. But common sense would be from the bottom notch to the top.

[Deltarider]

Standard we all count from the top (≠ tip!) down, so 4th is richer than 3rd notch. The lower the clip the higher the needle hangs.
2,5 turns (turn is 360^o) out is too lean and can cause popping.
Check also for faulty condensers (always, always start with the ignition!)
Air leaks between carbs and head?
Are exhaust gaskets in place?

[Tews19]

Standard we all count from the top down, so 4th is richer than 3rd notch. The lower the clip the higher the needle hangs.
Check for faulty condensers (always start with the ignition!)
Air leaks between carbs and head?
Are exhaust gaskets in place?

No air leaks from the carbs to head, no exhausts leaks either. Ignition is on. At least I hope all this is correct.

To be clear, the notch it is currently on is the stock one correct; 2?

I need to move it down now to the fourth? One away from the very bottom one?

[lucky]

That clip position would be wrong no matter what.
Put the clip at fourth groove DOWN from the top.

[Tews19]

That clip position would be wrong no matter what.
Put the clip at fourth groove DOWN from the top.

Thanks.

God I am an idiot.... SO I an counting from the top of the needle, the part that is in the sleeve? Down to the fourth correct? SO the clip will be closer the the sharp needle tip then it was previously?

[Tews19]

Also, do I seperate the clip using needle nose and spread it or do I have to do something where the integrity doesn't get messed up?

[Dimitri13]

I had no problem getting it off with needlenose. If you happen to break it, I'm sure you can get a replacement from a hardware store.

[Deltarider]

That clip position would be wrong no matter what.
Put the clip at fourth groove DOWN from the top.

Are you aware that Honda prescribes 2nd groove for the 550F-A (p. 165 Honda Workshop 500/550 Manual)?
Do you have any experience that tells us you know more than the manufacturer?
We tend to pass correct information in this forum. Personal experience can help, but we will not pass on "info" from hearsay unless our source is 100% reliable. If you think your source ís reliable, please reveal. Remember everything posted in the internet,right and wrong is here forever.

[Tews19]

That clip position would be wrong no matter what.
Put the clip at fourth groove DOWN from the top.

Are you aware that Honda prescribes 2nd groove for the 550F-A (p. 165 Honda Workshop Manual)?

I am aware it is recommended by Honda to be on the 2nd clip. But I have a free flowing muffler now and there is no back pressure. Am I going about this wrong? Any more insight would be greatly appreciated!

[Scott S]

 If you are lean and want to richen it up, move the clip towards the pointy end....towards your fingers in the pic.
 Think of it as working similar to the needle/seat valve that allows fuel into the float bowl. The tapered needle runs inside the emulsion tube. If you RAISE the clip, you LOWER the needle, thus allowing less fuel/air mixture to get around it. And vice-versa. If you LOWER the clip, you RAISE the needle, allowing more to flow past.

 You should be able to pop the clip off with a small, flat screwdriver. I like the pointy "hook" tools you can get in a multi pack. Work on a towel on your kitchen table or somewhere clean. When (not IF) one goes flying, you want to be able to find it. I get them started back on the needle with a very small pair of needle nose, then use the flat part if that small screwdrive to push across the back, non-open part of the clip until it snaps in.

[Deltarider]

I presume with popping you mean popping in the exhaust, right?
2,5 turns out is too much IMO. It's one turn more out than standard. That surely can cause popping. But always check ignition first (timing, free movement of advancer, capacitors). We did discuss gaskets and airleaks already. Are you sure there's no water in the fuel. Even a small amount can cause popping. So does old fuel. My bike pops every springtime and than after I filled the tank with fresh fuel it's gone. Pop till you drop!

[dave500]

lay the needle and clip on a flat surface with the clips open end facing down,now push the needle down out of the clip,no damage,dont spread the clip with pliers.

[TwoTired]

Your picture shows the clip in the 2nd notch from the top (relating to the top of the bike as installed on the machine).
That is the stock set up position for the 069a carbs and leans the midrange for the stock muffler system.
What I am recommending is going to the stock 022A setup with your experimental muffler (of unknown back pressure characteristics), as I know that set up works well with the stock 4 into 4 and the aftermarket MAC muffler systems.  I know both the stock 4 into 4 (early style) and the MAC iare more open and louder than the stock F muffler.  I don't have a clue about the Lossa's actual pressure characteristics, it's outlet area, or sound.  Lossa's internet adds seem to reference fitment to triumphs and claim rejetting is required.

I've also told him that 2.5 turns out on the pilot screw is too much.  That setting and the slide needle too low is likely the cause for decell popping AND poor throttle response off idle.

Cheers,

[Tews19]

Thanks all for the input on the carbs. I went with the 4th notch. I am swapping out the plugs tonight and will take pics. I am pretty sure there was no water in the fuel line as I have put over 800 miles on her so far. I hope that isn't to long of a duration to ride with popping on decel.

On a side note... After all the time posting on here how I will be attempting to clean the carbs. I finally did it today. Taking apart, cleaning and reassembly is not tough at all. I am kicking myself for paying someone to do it. Especially when I would look at the clock when it was at the shop being cleaned. One solid day of work not to bad.... Beats making myself angry when I have to take it back to a shop for poor work. Now I can get mad at myself for poor work and not how poorly I spent my hard earned cash.

Since it took me all day I will wait until tomorrow to tackle putting them back on the bike and syncing the carbs.

[Scott S]

 Did you remove/clean the emulsion tubes, too?

[Tews19]

I believe so. The brass tube that is inside of the carb body where the needle sits? It has holes up and down the body of the brass? If so to cleaned that. I used Valucraft to clean up all parts then used an air compressor to blow it out

[Tews19]

Quick update. Sixthwisconsin let me use his carb synchronizer.  Here is the first start with the carbs being cleaned. On 4th notch. 100 mains. 38 slow. Floats at 22mm.

Next few videos continue to tweaking process.
http://s1090.photobucket.com/albums/i373/Tews19/?action=view&current=031-1.mp4


http://s1090.photobucket.com/albums/i373/Tews19/?action=view&current=032.mp4

http://s1090.photobucket.com/albums/i373/Tews19/?action=view&current=033.mp4


 Last video is the end product. I  very pleased. Took her for a 30 mile ride around outskirts of waukesha.

http://s1090.photobucket.com/albums/i373/Tews19/?action=view&current=034.mp4Need to adjust the clutch.  If something looks out of tweak please let me know... Also, the decel popping is gone.

[iron_worker]

Great thread.

Makes me realize that I need to adjust my needle position as well! I also have some lean popping and bogging at low rpm acceleration.

IW

[Really?]

This is a nice little tool to have for the gauges.  I checked the sync on the gauges (i have the same ones) and found them to be a bit off.

Connect the four hoses to the T thing and the other hose to one carb.  The small end is just a plug.

I am not saying you did anything wrong.  Just a tip for the next time you check the sync on your carbs.  The bike sounds good to me.

[iron_worker]

Just watched the videos. That first blip of the throttle on the last video ... the throttle response is great! Hope to get mine running as good soon.

IW

[TwoTired]

They are such nice bikes when in tune.  Nice to see bar controls that aren't sum bleached.

Sounds like it is running pretty well. 

(Just a bit too loud for my current tastes.  I've already lost some of my hearing response because of repeated exposure to high sound pressure levels.  Once it goes away, it doesn't come back)

After you are satisfied with road performance, you might consider posting the final carb settings.

Cheers,

[Tews19]

The controls are in pretty good shape. I bought it off a teacher about an hour and a half from me. He posted it on CL last year and I was the first to respond. He had no pics but the price was great.. I think 450 or 400.

TT, do you think I should bump up the slow jet to 40? On the road the bike drives well. The exhaust seems deeper sounding now that it is sync'd. I want to do a few rides on the highway before I check the plugs. I guess I could have chopped them but I really enjoyed the satisfaction of this bike running and sounding as well as it did by myself. Taking into consideration I was afraid to take a tank off last summer and over the winter I tore her down to the frame.


Once again to everyone who helped me out with this.
Here is a reminder how she looked when I brought her home last summer

[TwoTired]

TT, do you think I should bump up the slow jet to 40? On the road the bike drives well.

I don't see why you'd want to change it if it is working ok.

Cheers,

[Tews19]

Quick update. Rode her to work today on the higway and she seems not not have the response as she had prior to the cleaning, jetting and sync.

Tank is extremely clean inside so I am not worried about rust in the carbs. When I gave her gas she seemed to hesitate around 4200 rpms. Flat spot 550's are known for?

Other then the hesitation the bike runs great. Idles awesome. No more blipping at lights or high idle. I may put on the sync today to check for any off readings.

I had the gauges set all the same. I saw XSMOOTHs video of his sync and his gauges read higher. Should I move it to where is are?

[TwoTired]

When I gave her gas she seemed to hesitate around 4200 rpms. Flat spot 550's are known for?

Maybe/maybe not.
Wouldn't it be nice if you were told whether the "hesitation" throttle position was running lean or rich?
Wouldn't it be nice if you knew at what precise throttle position (slide position/jet needle position) the "hesitation" occurred?  (Mechanical slide carbs have no knowledge or appreciation for engine RPM.  They know only air speed and vacuum parameters and respond solely to that.)
Wouldn't it be nice to know what air bleed screw setting was selected?

So, without a dyno's exhaust sniffer, observing spark plug deposits while at the "problem" throttle position might indicate what is happening inside and what the engine needs to correct the problem.  This is done with clean spark plugs, a test track, quickly attaining the problem scenario operation mode, holding it for a time period, and then killing the ignition, pulling in the clutch, and then reading the spark plug deposits.

I had the gauges set all the same. I saw XSMOOTHs video of his sync and his gauges read higher. Should I move it to where is are?

No.  It is a vacuum balance activity.  Actual vacuum level after balance is related to engine efficiency and idle speed.  Once balanced, it is what it is.  The carbs do not produce the vacuum the engine does.

Cheers,