TheSamba.com :: View topic - Solex 28-1 leak at throttle shaft help

Wed May 01, 2013 6:12 am

Item is a solex 28-1. PO had it rebuilt about a year and a half ago. My wife drives the 61 to work about 2 miles a day. I've been noticing about an hour after she gets home a drip at either end of the throttle shaft. I took the carb apart. The throttle shaft doesn't seem to be worn or oblonged. The float seems to be floating in the bowl. Needle and seat are free moving. It's as though its being feed gas after the car is off at a very slow rate. Should the choke close completely when the car is off or be open slightly? Any help is appreciated. Thank you.

Wed May 01, 2013 6:56 am

If the shut off valve is new it might be junk. Lot of reports the old valves are the only way to go.

Might try a second gasket between the valve and top of carb.

Choke depends on how much you need to have it closed to function properly. Too much and those piston rings will suffer from too much fuel.

Wed May 01, 2013 7:14 am

I have the stock return spring on the accelerator cable. I also ran a spring from the lever where the cable connects to a clip on the air filter to help it return a little better. at the last little bit it slightly sticks. Is it ok to run a spring as I described?

Wed May 01, 2013 8:13 am

I used to run an extra spring just like you described on my 28pict.It needed it with the extra throttle linkage I had from the S.charger I'm running.It didn't take long before it ruined the bushing with fuel running out same as you.My fix was I changed out the accelerator pump spring from one from a 30pict 1 .Stronger spring or maybe just newer.To fix the bushing I just used a good bottom half I bought here on a Samba ad.Its never worked better .Even when I had it stock. I saw these springs for sale and was going to give them a try if what I had didn't work. I have no idea if they would fit or work but they were so cheap it didn't matter.I never had to buy them though.

http://www.ebay.com/itm/8-HARLEY-DAVIDSON-CARBURET...mp;vxp=mtr

Wed May 01, 2013 9:19 am

I had some spare solex 30/31 carbs. I took the nut off the throttle shaft of the28 pict and took off that lock washer with teeth and replaced it with the washer that matches the profile of the throttle shaft from the 30/31. Also on the 30/31 I noticed between the carb body and the throttle lever there is 2 thin washers. I put one of these in the same place on the 28 pict tighten it back together making sure it wasn't catching and or dragging. We will see later today if this may help.

Wed May 01, 2013 5:45 pm

Would be better to oil up the throttle shaft. Plus make sure you do not have the accelerator cable too tight.

Adding extra washers to the throttle shaft is not going to seal it there. That was never designed to seal, but to be a bit of an air leak.

Since you have fuel dripping out of there the problem is fuel dripping down the throat of the carb when the fuel pump is no longer pumping.

Thu May 02, 2013 2:53 am

I have the same problem; there is some fuel dripping to the throttle shaft.

My question is: from where does that fuel come?

If I study a section of the 28 carburetor, it seems impossible for the fuel to reach the throttle shaft, except for the idle channel, but fuel, to reach it, should raise on then descend down.

I do not find any reason why my bowl chamber, after 2-3days, becomes empty.

Thu May 02, 2013 5:42 am

Yea, I measured the throttle shaft grip length with the stock washer then measured it with the 30/31 washer. It's the same. So I guess it doesn't make a real difference. Just the design of the matching profile washer seems like a design improvement idk. I keep everything so I still have the stock washer. No drips since I messed with it. Probably was something else I did that stopped the drip. I'm gonna keep an eye on it.

Thu May 02, 2013 6:51 am

herbie1200 wrote: I have the same problem; there is some fuel dripping to the throttle shaft.

My question is: from where does that fuel come?

If I study a section of the 28 carburetor, it seems impossible for the fuel to reach the throttle shaft, except for the idle channel, but fuel, to reach it, should raise on then descend down.

I do not find any reason why my bowl chamber, after 2-3days, becomes empty.

From the fuel system. Park with the front up hill and the gas tank is above the carb.

Even if you park on flat ground you can have problems in warm weather. New fuels today are more prone to vaporization in warm weather and with a hot engine. This turning from a liquid to a vapor can form bubbles in the fuel system which takes up more room in the fuel and thusly pushes the fuel up and into the carb. The fuel pump has one way valve in it, the fuel can not push back to the tank so it goes to the carb.

Same as above can happen if your fuel tank venting system is plugged up.

Once the fuel over flows the vent tube in the carb it drips down into the carb throat. Plus how old is your carb top to bottom gasket? How warped are those sealing surfaces??

Forgot to mention earlier that a cracked float or too heavy one will cause fuel drips in the carb. Had a float that looked fine, but once replaced the problem went away.

Thu May 02, 2013 7:17 am

Thekera, you have the best VW carb guy about an hour away from you. Tim out in Yelm can square you away. Read his feedback here, you wont find anything bad! http://volkzbitz.com/

Ben

Thu May 02, 2013 7:50 am

badufay wrote: Thekera, you have the best VW carb guy about an hour away from you. Tim out in Yelm can square you away. Read his feedback here, you wont find anything bad! http://volkzbitz.com/

Hey Ben, just read this thread and never could find this guy for my carbs, thanks for posting his info!!!!

Thu May 02, 2013 11:02 am

Not to threadjack, but Tim does amazing work! I've gotten 2 carbs from him and the dudes work is amazing!

Ben

Sat May 04, 2013 2:54 am

I contacted him. Nice guy and real close.