Solex fuel leakage issues

[JayGoss]

I have a couple of fuel issues with a rebuilt Solex that I'm sorting out, although they may be inter-related. One is there's an extra puff/exhaust detonation at idle similar to when valves need adjusting- but the valves have been adjusted. It's almost as if there's an extra drop of fuel falling into the intake. I just received the Rover after a restoration and it was set up at sea level (in VT) and it now resides at 7000 ft (in CO). According to the literature I have the correct main jet installed (117.5 for 7000-9000 ft) - although I do have a spare 120 (for 5000 to 7000 ft) as well. I'm hoping I can eliminate the popping via idle mixture/speed adjustments. What puzzles me is there seems to be fuel seeping/leaking at the area where the phenolic block makes contact with the intake. I haven't seen this before- but this is my first Solex and the first Rover I've owned/driven since moving from sea level to 7000 ft. Any ideas as to what might cause this seepage? Do you think the popping @ idle is a concommitant issue- or are they mutually exclusive? Thanks, in advance, for your help!

[jp-]

I rebuilt the original Solex on my 88". It had a similar problem prior to rebuilding. The leak appeared to come from the pheolic as you say, but I narrowed it to two sources. The first was the washer that actually hooks up to the fuel infeed pipe. The washer supplied in the kit was not fuel resistant enough and let the fuel seep down the body of the carb after a little while. I replaced it with a plastic one. Although, you could use rubber.

The next issue on the Solex is that the throttle shaft must be very tight in these things for them to work perfectly. A loose shaft allows air to be drawn in around itself which "fakes" the carb into thinking it needs more fuel and you have a fuel intake drip. You can actually take off your main air cleaner pipe and look down into the carb (with a flashlight) with the motor running and see the fuel dripping out.

The only other thing to check is to make sure that your accelerator diaphram is fully closed.

[Eric W S]

Solex's were sand cast which means that they are very soft. Brass can actually gouge them and you can actually warp the base, for example, by over tightening screws. Might be an issue.

Look down the carb and scheck to see if the butterfly has gouged the throttle body. you can feel it with your finger as well. If gouged, it will "grab" additional air during operation and throw you mix off. Sounds similar to what you described.

[jac04]

Do you have any issues with hot starting? I ask because the Solex on my 63 had an issue where it would push fuel into the intake after shut-down as the carb heated up. The symptoms were as you describe. I tried & tried to solve the problem, using a detailed Solex service manual that I have, but I finally gave up and installed a Weber.

[JayGoss]

Do you have any issues with hot starting? I ask because the Solex on my 63 had an issue where it would push fuel into the intake after shut-down as the carb heated up. The symptoms were as you describe. I tried & tried to solve the problem, using a detailed Solex service manual that I have, but I finally gave up and installed a Weber.

I do have issues with hot starting- sounds like what the manual describes as "siphoning". I have to turn the engine over for a while while holding the accelerator pedal down to get it to start. The manual suggests building a home made heat shield to keep the carb from heating up. I can live with the difficult hot starts- I was just hoping the seepage/leakage and popping while idling might be fixable. I've also noticed that the popping occurs at higher rpm's. I'm going to remove the air cleaner hose and take a look as some others have suggested. It's possible I may have a rebuilt carb where some details have been missed- and it's time to try a replacement. Will keep everyone posted. Thank you for the responses everyone.

[jac04]

^^ I also tried a heat shield and it didn't do anything.

[JayGoss]

^^ I also tried a heat shield and it didn't do anything.

You just saved me the embarrassment of showing up to a rover event with a cut up can of PBR mounted under my carb. Thank you!