pfenlon Posted July 31, 2018 Report Share Posted July 31, 2018 1300 MK1 Spitfire twin small SU carbs, cleaned chokes OK fuel level set, but poor running. Will not rev up. If I separate the carbs so I can use them individually, the front carb when operated is good revs up nicely and I can see the Delco Remy advance working properly. If I operate the rear carb, it splutters and bangs and the advance unit works the WRONG way. Have ordered a set of plug leads?? but on only 2 cylinders I drove it back under cover without a problem. What am I missing please. Quote Link to post Share on other sites
John390 Posted July 31, 2018 Report Share Posted July 31, 2018 Rusty tank, dirty fuel? Cheers John Quote Link to post Share on other sites
Peter Cobbold Posted July 31, 2018 Report Share Posted July 31, 2018 Pete, If the vac advance capsule is fed from the rear carb could that make the disy change?. Try it with the capsule feed on the SU blokced off. If the carbs have been in bits check that the pistons are sinking smartly with damper removed. Peter Quote Link to post Share on other sites
Ian Vincent Posted July 31, 2018 Report Share Posted July 31, 2018 Peter, what happens if you disconnect the vacuum advance altogether and block the take off. I would start from there and get both carbs running before reconnecting the vacuum pipe. Rgds Ian Quote Link to post Share on other sites
Nigel Triumph Posted July 31, 2018 Report Share Posted July 31, 2018 I would start from the beginning and work through a methodical tuning ritual: - check/adjust valve clearances - consider compression test at this point - check/adjust ignition timing - check and tune carbs. Hope this helps, the 1300 Spit unit is cracking, same power and same capacity as a 1275 Cooper S. Nigel Quote Link to post Share on other sites
pfenlon Posted July 31, 2018 Author Report Share Posted July 31, 2018 tomorrow the new leads arrive, after that I will take your advice and I thank you for it. Quote Link to post Share on other sites
Peter Cobbold Posted August 1, 2018 Report Share Posted August 1, 2018 Peter, what happens if you disconnect the vacuum advance altogether and block the take off. I would start from there and get both carbs running before reconnecting the vacuum pipe. Rgds Ian Ian, Nothing much. It advances the spark at cruise to get the best mpg, but the effect is subtle. Many capsules have seized without anyone knowing! Peter Quote Link to post Share on other sites
Nick Jones Posted August 1, 2018 Report Share Posted August 1, 2018 Back two plug leads switched over? No fuel getting through to back carb or float chamber to jet pipe blocked? Sticking valve on one of the back two cylinders? Head gasket gone between 3 & 4? Is it really a 1300 (8 ports) or a 1200 (6 ports, inlets siamesed). Mk1 would have been born with 1200. Nick Quote Link to post Share on other sites
pfenlon Posted August 1, 2018 Author Report Share Posted August 1, 2018 I am a Numpty, rear carb not operating the Vacuum unit due to stupid owner disconnecting the carbs from each other and the Vac pipe is in the front carb. new leads did nothing. checking the mixture rear carb very much too weak, Corrected but suspect fuel starvation from float chamber to the jet, Then the starter motor said goodnight, it was fitted in 1972 so didn't do bad A new one from Moss £78.00 A new one from GE Middleton electrical, city Rd Manchester £38.00 inc VAT To be continued. Quote Link to post Share on other sites
nowtelse2do Posted August 1, 2018 Report Share Posted August 1, 2018 This is going to be a long thread Peter. :D Dave That remind's me, i've a couple of photos from the Rochdale show. Will put them up. Quote Link to post Share on other sites
pfenlon Posted August 2, 2018 Author Report Share Posted August 2, 2018 This is going to be a long thread Peter. :D Dave That remind's me, i've a couple of photos from the Rochdale show. Will put them up. It is Dave, after fitting the new starter, and checking the Left carb for lunge ( it was clean) the starter solenoid decided to stay permanently "on" back to G E Middletons, tomorrows another day. solenoid was £18 + vat, Moss didn't have one. Quote Link to post Share on other sites
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