Running lean

[fancyketchup]

Ok, Ive been having a problem with my 76' for a couple weeks now and Im starting to get real frustrated. It started running high idle from being lean after I cleaned out some crud that got into the carbs(have fuel filters now). Here is everything that I have done/replaced:
-Carb boots(from 650central) and clamps
-Repaired pinhole in left carb diaphram
-Installed carb kits
-Cleaned main/pilot jets
-Set float height to 25mm
-Ultrasonic cleaned carbs-sprayed passages with carb cleaner followed by air
-Checked valve clearances after setting chain tension
-Replaced throttle shaft seals
-Cleaned air filters
-Checked compression 120 left 115 right dry.
-Checked points gap
-Replaced plugs with new BP7ES gapped at .025
-Resprayed with carb clean while bike running and can not find any air leaks
-When I bought the bike it had been previously gone through by a shop and I found the needle raised to the highest position and it had 120 mains installed. Im assuming because they could not get 122.5's without ordering them. Ive got some on order but until then Ive got it set like this. The bike ran fine until this point like this.

After all this and the thing still doesnt run right, when I try to set the mixture screws using the dead cylinder method the bike stalls after a few seconds on both cylinders. Ive checked the sync with a motion pro guage and its good. The idle revs up on its own and it has no power. Im really getting irritated, anyone have any ideas?

 

[nj1639]

How's the voltage when it's running?

 

[fancyketchup]

Off-12.7
Idle-13.3

 

[fancyketchup]

In the morning Im going to double check my float levels and maybe adjust them to 24mm? Im also going to recheck for air leaks. I have a feeling it is one of these issues. Or maybe I should just buy vm's.

Edit: When I installed the throttle shaft seals is it possible the butterflys are a little off? Would that cause a similar issue? Thanks

 

[fancyketchup]

Ok wtf... I got some fuel filters from Mikesxs and they look like they have melted? Only been on 2 days. The pilots were almost completely clogged, im guessing from my non fuel compatible fuel filters? I ran cleaner/air through all the passages again and cleaned the pilots and mains. Also set the floats to 24mm. Bout to reinstall and see.

 

[Pandorasglocks]

Sounds like a headache =/ So the bike was running fine before it got lean and then went haywire ?

 

[fancyketchup]

Yeah, as far as I could tell it ran good, plugs looked good anyways. I just ran it and the power is back but it still revs up and a slight backfire on deaccel that I can only hear without my helmet on... this is really irritating. Guess I will start back up on it in the morning.

 

[fancyketchup]

One of the other things I did was lube the advance mechanism, I did notice that the weights do not retract all the way unless you push them, does someone know if that is normal or should the springs pull them all the way back?

 

[XSLeo]

They should snap back shut every time. If they don't you can shorten one spring at a time by clipping the loop that hooks the spring on off and bending up the next coil of the spring for a loop. do one, test. If ok fine. If not clip the other spring.
This can be the reason your idle is hanging.
I might set the plug gap at .028. The bigger gap creates a bigger spark. I use a much hotter coil than stock and gap my plugs at .038. With the Better plugs I may try .040 gap.

 

[fancyketchup]

Thanks leo, Im gonna give it a shot this morning and report back.

 

[fancyketchup]

Set the plugs to .028, clipped one spring and now the atu retracts as it should, but still high idle after it warms up and plugs reading lean.

 

[5twins]

Did your carb kits come with needles and did you use them? These kits usually contain a generic Y-22 needle. No one really knows which of the earlier needles it is a match for, if any, so you're better off using the original 4M1 needle.

Idle speed should be set when the bike is fully warmed. Set it when cold and the bike will idle too high once warmed up.

 

[fancyketchup]

No needles in the kits, however I did order some needle/needle jets through mikesxs, havnt gotten them yet, are those the right ones? I did get it running right today, after fixing the advance I then took the carbs back out(for the 10th time) and loosened the butterflys and reset them with the idle screw completely backed out(made sure the holes at the top were covered by the butterfly). Then I warmed it up, synced it, set the mixture screws and voila! No more sticking idle. Thanks for all the help guys, now I just hope it stays this way.