Revolution Posted May 1, 2013 Report Share Posted May 1, 2013 Hello All Was having flooding issues with the front carb so have: Fitted new Grose jets, floats, gaskets to both carbs and replaced the rubber fuel pipes to each carb Great, no more flooding issues and car running well.......until today......front carb spewing out petrol from the bleed hole.....slackened off float chamber lid to release excess fuel and started car.....no flooding! I fear the problem will return Is it possible this could be a petrol pump issue somehow or is it still likely to be an issue with the front carb ? Any help would be appreciated as I've run out of ideas! Thank you, Nick Quote Link to post Share on other sites
stuart Posted May 1, 2013 Report Share Posted May 1, 2013 Check your rubber fuel pipes for degredation as it only takes a small bit of debris to do this.Also check your filters (if fitted) and the state of the inside of the fuel tank. Stuart. Quote Link to post Share on other sites
AlanT Posted May 1, 2013 Report Share Posted May 1, 2013 Float chamber needle valve. These get stuck open sometimes. Bad fuel, lay-up over winter, contamination the usual things. May need to remove and clean. Quote Link to post Share on other sites
peejay4A Posted May 1, 2013 Report Share Posted May 1, 2013 (edited) Do the Grose float valves suffer from sticking? Just asking because I have them. Edited May 1, 2013 by peejay4A Quote Link to post Share on other sites
ctc77965o Posted May 1, 2013 Report Share Posted May 1, 2013 I also vote for 'debris in the fuel line', bad tubing or defective gauze in petrol pump. Quote Link to post Share on other sites
Badfrog Posted May 1, 2013 Report Share Posted May 1, 2013 What kind of petrol pump? Old, NOS, refab? Some poor refabs push out too much pressure, around 7 psi. So do electric ones: the smallest "cubic" Facet unit pushes 7 psi, other push more are they are meant for mechanical carbs. Pressure regulator set at 3-4 psi can be the solution. Crud and debris are also great suspects. Grose valves don't stick, usually. Badfrog Quote Link to post Share on other sites
RogerH Posted May 1, 2013 Report Share Posted May 1, 2013 Hi Nick, I had similar issues with the rear of my carbs (HS6 TR4A). Having eliminated dirt etc I then went the other way and increased the gap in the float mechanism so that there should have been less fuel in the bowl. This did the trick. I can only assume that the extra force on the float (slightly more submerged) sealed the grose jet better. There is no logic to what I did, only desperation but it worked. Roger Quote Link to post Share on other sites
stuartmac Posted May 1, 2013 Report Share Posted May 1, 2013 the smallest facet pushes 7psi I hope you're wrong I had the road unit at 2.5 to 3, the fast road at 4 to 5.5, and the competion unit at 6 to 7psi Are you saying that the road unit actually does 7psi, contrary to the 2.5 to 3 stated I'm halfway through the install and if thats the case I now need to buy a regulator as well, I'm trying to reduce the number of components, not add to them! Quote Link to post Share on other sites
Ashley James Posted May 1, 2013 Report Share Posted May 1, 2013 What Stuart said first, but make sure fuel pressure is what Burlens say it should be because SUs don't like excessive pressure. Quote Link to post Share on other sites
Badfrog Posted May 1, 2013 Report Share Posted May 1, 2013 Stuart, Your figures are right, but they're catalogue figures. I have found reality to be quite different. And yes, you need a regulator with an electric pump. In a nutshell, forget Facet, get a Huco pump: http://www.gowerlee.dircon.co.uk/HUCO.html Did that. Happy camper. Badfrog Quote Link to post Share on other sites
Revolution Posted May 2, 2013 Author Report Share Posted May 2, 2013 Thank you all very much for your advice - will be working backwards from the carbs to the fuel tank looking for muck !! Nick Quote Link to post Share on other sites
BrianC Posted May 8, 2013 Report Share Posted May 8, 2013 (edited) Hi Nick, I had similar issues with the rear of my carbs (HS6 TR4A). Having eliminated dirt etc I then went the other way and increased the gap in the float mechanism so that there should have been less fuel in the bowl. This did the trick. I can only assume that the extra force on the float (slightly more submerged) sealed the grose jet better. There is no logic to what I did, only desperation but it worked. Roger Had this problem with mine (actually H6s with standard needle valves set as per spec) and in desperation, did the same as Roger - so far, so good, after several thousand miles. Edited May 9, 2013 by BrianC Quote Link to post Share on other sites
stuartmac Posted May 8, 2013 Report Share Posted May 8, 2013 (edited) Just to update the question of fuel pressure above I have fitted a Facet interrupter style pump (I initially bought a cube type but ended up putting it in the bin - I may have bought a HUCO but didn't have the patience to wait 48 hrs!!)rated at 4.0 to 4.5 psi. After the above advice I fitted a regulator from the outset, turned right down to 0.5psi and still works ok - no leaks, flooding, starvation etc. One day Ill get an accurate gauge and get a proper pressure reading. PS - what type of jets have the black rubberised tips because they are useless!! I bought some rebuilt HS6's that had them fitted, just by blowing through the chamber lids by mouth and working the float with my finger I could tell they were not going to perform properly,changed them for my originals and no issues. Edited May 8, 2013 by stuartmac Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.