Help with float levels

[OneHand]

OK, here goes...(Again!)

I have now read every tech tip and thread on the above and can't seem to get a definite answer or picture. Don't hav a manual. PLEASE HELP! For ref : 79F

The long of the short : Pulled carbs, cleaned etc. Float levels were
all mixed up. I kept finding reference to 25mm, so I set them all to 25mm - From the edge of the carb bowl seat to the top (bottom) of the float (It's upside down, right?) when the little thingie in the needle is pushed in. Is that wrong? Should it be 25mm when it is just resting on the needle? Or where should it be measured?

Results: Fired up first touch of hte starter button with full choke.
Idled OK, but the rev pickup has quite a hesitation, and idle sounds very rough. Went out for a quick ride, +- 6mi. Battling to pull off, but once past 3.5K ran fearly strong and smooth.

I pulled the plugs when I came back, just to find 1,3,4 seems Ok, allthough bit brown (lean?)2 still wet, header pipe cooler than the others. A bright light goes on! I couldn't get the Pilot out of no 2. Could a blocked/mangled pilot cause too rich? Also put new idle screws in, all at 1.25 turns out as recommended, and did a bread-tie sync. New 140 main jets(Weber?) Went up in jet size for the 4 in1 and non-standard filter in drilled airbox.

More problems... Went for a second ride, same route. Felt even worse! Losing power, throttle response very bad. Just made it home. Felt like running out of fuel. Check spark - OK. Tank off, check fuel flowing when sucking on vac pipe, I expected to see more fuel, but should keep it running. Had to give quite a suck. On prime it gives a good squirt?

While idling (badly) I pulled the choke to 1/2 and the revs jumped up to 4K, sounding possibly smoother - Making me think it's running lean? Also when closing the throttle, the revs drop very slowly down to idle speed, currently 1.5K - Out of sync?

Quess the carbs will be coming off again!!

Any suggestions and pics? THX

1H

[Ken Talbot]

Start off with the 25mm measurement from the carb body to the highest point of the float, while the float is just resting against the spring-loaded pin in the needle valve. The correct setting may end up being something else, but you need to start with some consistency before you start adjusting everything else.

Pilot screws set to 1.5 and a careful bread tie sync should get you running, but you will be beating yourself up until you get a proper sync tool. I like my inexpensive mercury sticks, but some guys like the gauge type. Either way, I wouldn't worry about going to much further with adjustments without a sync tool.

[pggg]

Hey Onehand I sent four 137.5 main jets, four 42.5 pilot jets and four float valve needles in an envelope to that address you gave me, they should turn up soon, to sync the carbs, do it by eye, there's 3 tiny fuel holes above the butterfly in each carb, set the butterflys so they half cover the front fuel hole in each carb, set those floats at 25mm just sitting flat upside down, I'd be checking the slide needles to be sure they're all the same size and all set on the same notch. You need a thin pair of circlip pliers or suchlike to remove the slide needles. Those petcocks could probably do with a strip & clean out too, also good new rubber hoses all round including vent hoses, vaccuum hoses and fuel hoses.

[TopCatGr58]

I couldn't get the Pilot out of no 2. Could a blocked/mangled pilot cause too rich?

Just to add, YES! The Pilot jets have small aeration holes in their sides, and could get gummed up. Look at the ones you are able to remove! So...with only the central hole/channel open, the pilot is NOT sucking in air thru those plugged holes to mix with the fuel, so it's running richer, flooding, hence the wet plug!!

You'll need to see about getting a reverse thread drill bit to get that jet out and then replace with either PGGG's, or other source!

I had a sticking float once, and would be flooding my #2 cylinder, and it totally screwed up the low rpm response until I would open it up enough to get into the mains, then it would run strong!

It's fairly common and normal with 4-1 pipes to have popping on decel. Poor sealing exhaust gaskets can also cause that. Mine used to do it quite a bit. I replaced the gaskets and it cut it down considerably, but it still does it some! A turn out of the pilot screw may help reduce that, but you'll want to get that pilot JET fixed first!
T.C.

[OneHand]

Thx guys!

At least I know now where half the problem lies. The floats levels would then probably be +-28mm currently. Will fix that. Soon as the jets etc. lands from NZ, I'll stick those in there. Hav to go find an EZ-out or reverse drill bit this week to get that pilot out. The others looked clean but mangled. OK, but you never know how long that #2 has been stuck in there.

I have also ordered a single vacuum guage, and will be putting together a sync tool when it arrives.

The floats all seemed in good shape, not sticking and closing the needle, but I'll check again. I have replaced the hoses, but petcocks up for a clean also.

Thx a lot, will let u know how it pans out.

1H

[oseaghdha]

Couple of thoughts:
You can run it on "Prime" to see if that makes any difference. If it does you have a clogged line, petcock, or bad diaphram.

I had to drill one of the pilots out. I used a bit that was just smaller than the minor thread diameter. Very carefully drilled until I felt the bottom of the jet begin to spin. I then was able to pick the brass threads out with a small tool and remove the the rest. You have to stay on center and square to avoid cutting into the threaded part of the carb body. The drill will want to follow the pilot thru hole. I was able to free hand it but a drill press is preferred. A machine shop would be better.You can FUBAR the carb if you don't do it right. Clean out with a tap and plenty of air and spray juice.

[xj11john]

OneHand,

Sounds like you are on the right track with all the good advice you are getting.
I don't know if you have discussed this already, since I havent seen your previous thread, but if not - one more thing to check is to make sure your vaccuum diaphams are operating properly, with the diaphram cover off pull out each diaphram and make sure that each one glides down without and catching or too fast to make sure you have the right vaccuum and no pin holes in you diaphrams. If you do have pinholes in the rubber diaphrams there is tips on using plasti-coat to seal them up, or take the hit on new ones, but it does sound like those float levels, and synching your cabs is all it will take, good luck!

[red bandit]

I couldn't get the Pilot out of no 2. Could a blocked/mangled pilot cause too rich?

I use a #1 easyout, sometimes aply a LITTLE heat from a torch on the tower. It makes old gummy gas soft. Don't have to worry about fubaring something up with a drill.

[OneHand]

Diaphrams

Hi John,

I havn't taken the diaphrams out yet. Have moved the slides up and let it come down by itself. All 4 move smoothly, at a sedated pace. If the new jets and needles + syncing dont fix it, I'll take them out as well. Dont really want to fiddle there if not neccesary. Won't be able to get new ones in SA, unless I get them off e-bay or such.

Thanx for all the help so far.

1H

[OneHand]

BIG Thanx to PGGG!!!

Have to extend my biggest possible gratitude to PGGG for sending me some jets, float needles and such. It arrived yesterday (Wed)

I'ts not everyday that you find someone that is willing to help out, and not expecting anything back. I will remember the favour and hopefully one day be able to assist Pggg or someone else in a similar manner.

Thank you!

1H