slickyddyer Posted August 18, 2012 Share Posted August 18, 2012 So got the mk 5 going again after it's respray midnight purple. It's got the 2L now and I put some twin 45 dellortos on it I got from trade me. It idles ok but want to die when throttle is opened up. Iv'e never tuned twin carbs before so I'm wondering if anybody can reccomend someone in christchurch to do it? Also can anybody tell me roughly what timing advance suits? I'm running 8degrees at the moment but I think it may need more. And 8 degrees is the last mark on the crank. Quote Link to comment Share on other sites More sharing options...
Llama Posted August 18, 2012 Share Posted August 18, 2012 It's easy enough to add another mark, just turn it over until you get to the 0 deg, put a mark where the 8 deg is, then turn it around again until the 8 deg mark reaches the new mark, the make a new one so you have 16 deg. Or repeat with any deg you want. As far as tuning goes I'm no help sorry. Quote Link to comment Share on other sites More sharing options...
shizzl Posted August 18, 2012 Share Posted August 18, 2012 thats the exact colour my first mk5 was... so it sounds like its bogging when you open it up? is that under load or free revving? Quote Link to comment Share on other sites More sharing options...
slickyddyer Posted August 18, 2012 Author Share Posted August 18, 2012 Both. Revving and under load. Probably too rich or too lean. It doesn't have an exhaust yet. Just headers. I can't see any moisture or petrol flying out the end of the headers so i would think lean. Although I had a play around with the mixture, I gave up. It's tricky. Also the temperature gauge flies of the richter pretty quick and flickers on the end of the hot scale. Not sure if this is an electrical fault or if it's actually the temperature. The temp probes brand new. When I drive it around the block the temperature gauge flies around up and down pretty quick. Quote Link to comment Share on other sites More sharing options...
shizzl Posted August 18, 2012 Share Posted August 18, 2012 i was thinking more on the lean side. ive seen guys tuing using a infrared laser temp reader,and going off the exhaust temp as it enters the extractors from the head. dont know how accurate it would be though.. isnt there a alfa romeo specialist in chch that could probably tune twin carbs pretty well, maybe hit them up if theyr still around Quote Link to comment Share on other sites More sharing options...
Horse25 Posted August 18, 2012 Share Posted August 18, 2012 palmside tuned the 45's on the 2.0L i have, What work have you done to the 2.0? Quote Link to comment Share on other sites More sharing options...
shizzl Posted August 18, 2012 Share Posted August 18, 2012 would 45s be a bit big for a stock 2l? good excuse to get some head work done, or atleast a fast rd cam haha forgot about palmside Quote Link to comment Share on other sites More sharing options...
Horse25 Posted August 18, 2012 Share Posted August 18, 2012 yeah if it was stock that's what i was thinking but could always change the jets etc? I think it was around the 200ish mark to get it tuned there. ive had it done there twice in the last two years. Quote Link to comment Share on other sites More sharing options...
bigmatt4 Posted August 18, 2012 Share Posted August 18, 2012 can you tell me wot jets you are running? from what i can see in the photo the rear carb is been choked with the air filters squashed against the battery. Has the distributor been re curved? wot distributor does it have bosch or motorcraft. with a bosch distributor i run it about 10 deg static motorcraft about 8 deg static. 0.025" points gap 0.025 plug gap and no vacume advance jets to start with 36mm chokes 7772.6 or 7772.5 Emulsion tubes 145 Main jet 190 Air corrector idle jet size 50/55 idle air jet holder size 7850.2 i would start tuning with a 45 idle jet to prevent plug fouling ideal idle mixture should be between 1.5 and 2.5 turns out. (MAKE SURE THE CARBS ARE BALANCED FLOATS ARE SET AND TIMING IS CORRECT BEFORE ANY JET CHANGES ) You will have trouble otherwise. Are you running electric fuel pump or standard mechanical? if electric you must not exceed 3.5 psi or they will flood and leak fuel. basics for jetting are idle jet works from roughly idle to 1700 rpm main from 1700 to 3500 rpm airs from 3500 rpm up give or take. besy way is to get idle right then road tune to 3500rpm using light throttle by checking sparkplug colour every 1000rpm ( hot shutdowns) it should be biscut brown then when thats right do some full throttle runs checking plug color dont idle between tests plugs can change color very quickly. it all takes time but it is possible good way to learn your carbs too. note generally if it surges and backfires out the carb its lean and if it boggs and bacfires out exhaust its rich Quote Link to comment Share on other sites More sharing options...
shizzl Posted August 18, 2012 Share Posted August 18, 2012 awesome bit of info there bigmatt Quote Link to comment Share on other sites More sharing options...
slickyddyer Posted August 18, 2012 Author Share Posted August 18, 2012 It's had a bit of porting. Had valves cleaned up but still standard size. Running a fast road cam. Na I don't know how the carbs are set up although they came off a 2L pinto with a hot cam. So I would think they would be set up for this motor. Standard dizzy but Iv'e got an electronic one to go on. Just gotta get the sparky to cum round and change the wiring to suit. And get the lights going and a couple wee bits. Ive got a couple wires without homes. Can't remember where they went hehe. Quote Link to comment Share on other sites More sharing options...
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