carld Posted November 18, 2008 Report Share Posted November 18, 2008 Hi I have an issue with my GT6 and thought I would try my luck with you guys. I recently had a new clutch fitted as the bearing was whineing away. It was then driven back to my home with no issuess. I then started to strip out the interior, which I then re carpeted and fitted inertia belts. The weekend before last I put it all back together, the weather was sunny so I took her out for a run, the car filled with fuel smoke and was running terribly. I opened the bonnet to see fuel pouring out through the air filters? She is fitted with Stromberg 150 cd`s, there is a lot of moisture under the rocker cover. Any ideas as to the problem here Cheers Carl Quote Link to post Share on other sites
jerrytr5 Posted November 18, 2008 Report Share Posted November 18, 2008 Well, if fuel's pouring out it must be a stuck float valve. You could try gently tapping the float bowl (that's the rectangular tank under the carb) with a small hammer to see if that frees it before taking it apart. I foound this with a quick search which might be useful. http://www.triumphspitfire.com/images/carbs/zs1.jpg Jerry Quote Link to post Share on other sites
Kiwifrog Posted November 18, 2008 Report Share Posted November 18, 2008 If its not a sunk/stuck floater it could also be a stuck valve. replace them with gross jets Cheers Alan Quote Link to post Share on other sites
carld Posted November 18, 2008 Author Report Share Posted November 18, 2008 Thanks guys, its not the floats and I suspected a stuck valve. anyone got any other theories to work through. Cheers Carl Quote Link to post Share on other sites
Badfrog Posted November 18, 2008 Report Share Posted November 18, 2008 Hi, Strombergs are just low-life flower pots. get SU carbs. Cheers, Quote Link to post Share on other sites
carld Posted November 19, 2008 Author Report Share Posted November 19, 2008 Hi, Strombergs are just low-life flower pots. get SU carbs. Cheers, Badfrog Understand where you are coming from, but I am confident that the issue is not carb related. Alan - Gross Jets? sorry dont understand. Cheers Carl Quote Link to post Share on other sites
Guest ntc Posted November 19, 2008 Report Share Posted November 19, 2008 (edited) Badfrog Understand where you are coming from, but I am confident that the issue is not carb related. Alan - Gross Jets? sorry dont understand. Cheers Carl Hi Carl It will be the carb's or the fuel pump my guess the rubber diaphragm are split on the top remove them stretch and look for cracks or holes this will cause the needles to stick. You might get more replies if you moved the subject to the main page of the forum Regards Neil Edited November 19, 2008 by ntc Quote Link to post Share on other sites
Kiwifrog Posted November 19, 2008 Report Share Posted November 19, 2008 (edited) Alan - Gross Jets? sorry dont understand. Cheers Carl Gross Jets, direct replacement for the float valve needle and seat. Ball bearing based in theory should never stick Nothing wrong with Strombergs just less tunable than SU's Cheers Alan Edited November 19, 2008 by Kiwifrog Quote Link to post Share on other sites
Rex Wyer Posted November 19, 2008 Report Share Posted November 19, 2008 Carl, why is it that every time you buy a car you have this tendency to rip out the interior trim and replace it. ? Can you not find a car with a trim you like, or were you an upholstery fitter in a previous life. ? regards Rex Quote Link to post Share on other sites
BrianC Posted November 19, 2008 Report Share Posted November 19, 2008 Gross Jets, direct replacement for the float valve needle and seat. Ball bearing based in theory should never stick Grose Jets Nothing wrong with Strombergs just less tunable than SU's... ...and an Achilles' heel in the diaphragms (a good item to carry as spares) Quote Link to post Share on other sites
67_gt6 Posted November 20, 2008 Report Share Posted November 20, 2008 Carl, is sounds very much like sticking needle valves in the carbs, this will cause fuel to pour out the filters. The valves on my GT6's Strombergs always used to stick if I didn't run an inline filter right before them, cheap one from Halfords will do it. The float heights must also be set correctly, you can only do that with the carbs off the car so you can invert them. Andy Quote Link to post Share on other sites
67_gt6 Posted November 20, 2008 Report Share Posted November 20, 2008 Hi CarlIt will be the carb's or the fuel pump my guess the rubber diaphragm are split on the top remove them stretch and look for cracks or holes this will cause the needles to stick. You might get more replies if you moved the subject to the main page of the forum Regards Neil Definitely worth checking the diaphragms as a split one will cause poor running but it won't cause your symptoms - a split diaphragm will cause the piston not to rise in the chamber, and thus the metering needle won't rise in the jet so you won't get the correct air/fuel ratio. Not the same as a sticking needle valve, which will cause a flooded carb like you have experienced. Andy Quote Link to post Share on other sites
Tom Fremont Posted November 20, 2008 Report Share Posted November 20, 2008 Carl, is sounds very much like sticking needle valves in the carbs, this will cause fuel to pour out the filters. The valves on my GT6's Strombergs always used to stick if I didn't run an inline filter right before them, cheap one from Halfords will do it. The float heights must also be set correctly, you can only do that with the carbs off the car so you can invert them. Andy I'll second that except I was always able to set the floats on mine in situ using a small measuring caliper ( 5/8" is the distance from the bottom of the float to the carb body ). You could make up a cardboard gage just as well. On my '250s I never had sticking floats, but always used an inline fuel filter as advised. Standard float needles too. I can't imagine any other cause unless using an unregulated electric fuel pump; the stock AC type can't generate enough pressure to cause this IME. Quote Link to post Share on other sites
carld Posted November 20, 2008 Author Report Share Posted November 20, 2008 Thanks guys I have replaced the carbs with another set that had just been renovated and taken off a car that was running fine. The same is happening again. I stripped the other carbs and diaphragms were fine. Off the forum, I am being told stuck valve, cracked head, burnt out valve and so on. Head off at the weekend I guess. Very funny Rex, made me snigger for a while, carpets were horrible and in complete, had to go. No cream in sight this time ! all black. Cheers Carl Quote Link to post Share on other sites
carld Posted November 25, 2008 Author Report Share Posted November 25, 2008 OK Head off, took to local engineering place, skimmed, crack tested and valves checked etc. Re fitted and still the problem persists. It seems somehow that the fuel is being pressurised, yet its a manual pump. Confident that its not the carbs. Any further ideas welcome. Cheers Carl Quote Link to post Share on other sites
Guest ntc Posted November 25, 2008 Report Share Posted November 25, 2008 OK Head off, took to local engineering place, skimmed, crack tested and valves checked etc. Re fitted and still the problem persists. It seems somehow that the fuel is being pressurised, yet its a manual pump. Confident that its not the carbs. Any further ideas welcome. Cheers Carl Air vent blocked in the fuel cap ? Regards Neil Quote Link to post Share on other sites
Kiwifrog Posted November 26, 2008 Report Share Posted November 26, 2008 (edited) Carl Check the needle valves on the carbs you took off as I still think its highly likley to be your problem. Modern petrols emulsify very quickly leaving a sticky residue behind. If the new carbs had been used then taken off a car its highly likely that the old fuel in them has evaporated leaving behind a sticky layer. Have you actually taken the tops off of the float chambers to check that the needles move smoothly ? I cant see how the head could cause your problem. Have you checked the crank case breather as if this is blocked it could cause pressurization somewhere although I am not sure it would cause the pump to become pressurised. I would start with the basics Check the pressure at the output from the pump, should just be a weak spurt if it is a mechanical pump then double check the float valves. did you actually see the new carbs running ok on the other car ? Cheers Alan Edited November 26, 2008 by Kiwifrog 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.