Adjusting SSI 27D float level

[vintagetour]

Looking for some help in adjusting (lowering) the float level in my Dellorto SSI 27D. I have determined my rich mixture is due to the fact that tickling the carb causes the gas to bleed higher than the level of the air passage of the "leaning" (not choke) chamber on the right side of the carburetor. Getting back to the adjustment problem. I know that old Amals can be adjusted by pressing the seat up or down to adjust the level. Does the seat in the float bowl top press up and down in the Dellorto? I have tried tapping it whit a flat punch but I do not want to get to rough with it until I know for sure. The parts drawing shows the seat and threaded lid to the float as one part number (with the exclusion of the tickler parts). If the seat does not press in and out then do I have to order the whole lid assembly? And then how would you ever adjust the level?

[Bevel bob]

I don't think there's anything wrong with the level, its supposed to flood out with use of the tickler,you can raise the fuel level by rotating the float chamber and moving it closer to the frame spine or tipping the whole carb after loostening the clip to raise the chamber in relation to the body.If the carb drips without useing the tickler then the level is too high (tap the chamber with a spanner to check the floats not hung up).My bike ran a lot better after i raised the level by tilting the carb.Rich mixture is more likely due to worn needle jet ,whats the bike and whats the carb specs?.Slide size,main jet ,pilot, needle and emulsion (needle) jet?.

[vintagetour]

I have determined that gas flows out the mixture screw hole even when the carburetor is not tickled indicating my float is not shutting off. The mixture screw hole is higher than the leaner air passage no matter how you twist the carburetor or float. My main jet needle is good but it appears that the gas level is staying higher than the leaner passage which is the same level as the atomizer body. This explains why I have to run the leaner lever fully pulled to keep from fouling plugs. I am in search of new float needle and seat. Dellorto.com has the seat (float bowl lid) but they do not show the clip type float needle I have. Any supplier suggestions?

[JimF]

I would have to agree with Bevel Bob. The tickler floods the bowl which in turn makes raw gas burble above the jet right at the carb inlet. This is just a different way of getting the fuel mixture richer for starting (as opposed to a chokle which makes the fuel mixture richer by choking off air.)

The float level is fixed and is not meant to be changed. I used to have the same notion that the float level was wrong and that my bike was running rich as a result. Seeing as the float is not adjustable and has been this way since the dawn of 1960, I started trying to figure out what could be adversely affecting this fixed level. I thought it might be modern fuel versus old fuels, I looked into what specific gravity is thinking whatever the heck that is had something to do with it, or maybe atmospheric pressure has changed over the last 50 years etc.

I took it as far as determining that the best way (in my estimation) to change the float level would be to add another notch on the float needle in the float bowl so I might be able to change when the float rises relative to the amount of fuel in the bowl.

But to be honest, I now believe I was all wrong. The fixed float level is perfect being as it is attached to the carb body. I later resolved my rich running problems using different jets in the carb.


OOPS! Late in posting this one and I see you have moved on. Could you lap the float needle into the seat in the float bowl?

Jim

Jim

[Bevel bob]

It is possible to lap in the seating with a little toothpaste or ally cleaner, keeping the needle at 90 degrees from the seat, a small amount of fine sediment will also stop the needle closing.Check everything else before you do anything drastic,parts for these are hard to get.You can check the level with a tube but if the seat is working there are plenty of ways to lower the level without messing with the seat/needle.I had regular flooding untill i flushed out the tank, filter ,pipes and taps.Getting the mixture right can be a pain with this carb, even a change of fuel regular/super can give me a problem.I am using a 260 n/jet,a 60 slide and a 110 main on a 250.

[vintagetour]

First of all thanks to all who have replied. Even if it something I have already tried it helps me know that I am on the right track. I have set up a bench test to enable me to make adjustments using clean fuel. I have tried lapping the needle and seat but it looks like I need to try again because as you say these parts are hard to find. This by the way is on a 67 250 Scrambler. Without tickling the carburetor I have fuel seeping from both the weep hole (below leaner passage)forward of the adjustment screw and the adjustment screw itself which is higher in elevation (I have duplicated the angle of the carburetor by attaching it to a fork tube clamped in a vise) than the air passage from the "leaner". I have reduced the main jet from a 112 to a 108 but it still runs rich even with the leaner cable pulled full. When I fill the empty bowl, fuel weeps from both holes within a minute. When you tickle the carb for even one secound it weeps fuel from both holes and drips heavily for about five minutes before slowing to a drip per secound. Depending on how long you leave the fuel on, the level varies from 2/3 up the side of the float (in the shut/off position) to just over the top of the float. Adjusting the angle of the carburetor and the float bowl do not seem to change. I am thinking that before I worry too much about jetting I need to get the fuel level below the adjustment screw and eventually stop dripping from the weep hole forward of the screw.

[Bevel bob]

Untill you stop the flooding anything else will be a waste of time. try removing the tickler in case its set too close to the float.Has the float been repaired with lots of solder?.Does the float leak?.

[AIRMANBLUE]

I have spent many years adjusting SS1 Carbs and it seems clear that your float is not seating properly and thus allowing fuel to get past the cut off . Bevel Bob is right .The size of main jet is not connected to a flooding problem and if you removed or blocked Airmanble the main jet completely the symptoms would still remain the same. The angle of the float is critical and the bike must be vertical when adjustments are made.I have just been tinkering with my Mach 1 which has a D Series SS1 and had not been fired up for some 10 years . Fuel flooded out when the tap was turned on and inspection of the float chamber revealed corrosion on the shut off . A few mins with some metal polish did the trick and everything is dry as a bone . The Mach 1 does not start any easier and actually needs flooding !! . I wonder if the engineer who created that curved kickstart lever is still in hiding ?

[vintagetour]

Good news, the float needle is now seating with some polishing on it and the seat. I will try to figure out some way to check the level with some clear tubing. Then I will be satisfied..... maybe.

[Bevel bob]

Hi Airmanblue, Its comforting to hear i have an SSI expert right on my doorstep!!.Wish i had known that a year or two back.I still have unresolved issues with my SSI29D, what i really would like is an on board sensor to monitor the mixture at different positions ,perhaps an 02 welded into an old front pipe and a reader on the bars.If there is an old pipe going spare it would be an interesting experiment.I am often in your area on my Mark3 if you want to meet.