J J Posted July 7, 2023 Author Share Posted July 7, 2023 I meant to add that I took the rocker cover off to check and the pushrod on No2 valve was loose and the valve was stuck down, I managed to free it and it popped up I set do that no1 and no8 were rocking which I think is right Quote Link to comment Share on other sites More sharing options...
yorkshire_spam Posted July 7, 2023 Share Posted July 7, 2023 To be honest @J J I can never remember the "rules" so I just turn it over by hand in the right direction and watch for the inlet on #1 closing and then the next tdc on the crank is the firing datum. Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 8, 2023 Share Posted July 8, 2023 On 07/07/2023 at 06:41, J J said: I meant to add that I took the rocker cover off to check and the pushrod on No2 valve was loose and the valve was stuck down, I managed to free it and it popped up I set do that no1 and no8 were rocking which I think is right JJ, You missed it. There are two ways to get the valves at the right position to set the clearance. One is to turn the engine until the valve that will give a sum of 9 when added to the valve to be adjusted is fully open. So, for example, to adjust valve 3 you want valve 6 fully open. The second system is to have pairs of valves "on the rock" to adjust a second pair. Those pairs are as follows: Open valves ............................... Adjust valves 1 and 3..............................................6 and 8 2 and 5..............................................7 and 4 6 and 8..............................................1 and 3 7 and 4.............................................2 and 5 If you find any of those pairs on the rock when you start, you can follow in the order I have given them to adjust all of the valves. This minimizes the number of times you must turn the engine to complete the process. Regards, Paul Quote Link to comment Share on other sites More sharing options...
J J Posted July 8, 2023 Author Share Posted July 8, 2023 Thanks Paul that made perfect sense and the job is now done however now it won’t start but I noticed that the coil centre connection is arcing to either the +ve or -ve terminals when I turn the distributor which I’m guessing is stopping it starting, could this be a coil problem? it reads 3.5 ohms across the terminals best Julian Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 9, 2023 Share Posted July 9, 2023 20 hours ago, J J said: Thanks Paul that made perfect sense and the job is now done however now it won’t start but I noticed that the coil centre connection is arcing to either the +ve or -ve terminals when I turn the distributor which I’m guessing is stopping it starting, could this be a coil problem? it reads 3.5 ohms across the terminals best Julian Julian, That could be a coil problem. But first give the top of the coil a good clean to make sure there is nothing to aid the spark going to the primary terminals. Then check the timing to make sure the rotor is pointing at least close to the number one post on the cap when the engine should fire. If the spark has no easier way to ground than jumping on the top of the coil that is what it will do. Regards, Paul Quote Link to comment Share on other sites More sharing options...
J J Posted July 10, 2023 Author Share Posted July 10, 2023 Thanks Paul with the lead attached the arcing stopped, however it still won’t start and I’m losing the will to live! there is a spark albeit quite weak, same non start result with both distributors, 125 bar compression on all cylinders and there’s good fuel supply tappets are adjusted (hopefully correctly) the electronic distributor will only fit into the drive one way and I installed it with the No1 piston at the top and the arm pointing to no1 post could the weak spark be the problem? any thoughts? julian Quote Link to comment Share on other sites More sharing options...
standardthread Posted July 10, 2023 Share Posted July 10, 2023 (edited) 2 hours ago, J J said: tappets are adjusted (hopefully correctly) the electronic distributor will only fit into the drive one way and I installed it with the No1 piston at the top and the arm pointing to no1 post The distributor WILL only fit in the drive dog one way, BUT, the slot in the top of the drive dog is offset. So if the drive dog has been dropped in the wrong way round the ignition will be 180' out, I know, I did it when I re-coned my first engine, and learned from my mistake. Photographs in a decent workshop manual show how the dog should be fitted, there is a free version someone on the forum has posted as a pdf. This is the page from my Standard 10 manual, but they are all the same. Edited July 10, 2023 by standardthread photo 2 Quote Link to comment Share on other sites More sharing options...
yorkshire_spam Posted July 10, 2023 Share Posted July 10, 2023 That's great info @standardthread haven't seen it explained/pictured so clearly before. Quote Link to comment Share on other sites More sharing options...
J J Posted July 10, 2023 Author Share Posted July 10, 2023 Thank you so much for explaining this so simply, a job for tomorrow Quote Link to comment Share on other sites More sharing options...
glang Posted July 10, 2023 Share Posted July 10, 2023 28 minutes ago, J J said: Thank you so much for explaining this so simply, a job for tomorrow But your dizzy gear drive hasnt been out has it Julian? I thought you had just changed the dizzy but not touched the gear so the dog slot cant have changed and you cant have got the installation wrong.... Quote Link to comment Share on other sites More sharing options...
J J Posted July 11, 2023 Author Share Posted July 11, 2023 You’re right the dizzy gear hasn’t been out, I was going to check the drive just in case I put the electronic dizzy back in and it started, revved very high, spluttered and died powerspark are sending a replacement electronic module and I’ve bought some new silicon leads….not sure if it will help i took a look at the carbs and noticed that the float chamber adapters are split and very worn, not sure if they’re significant losing the will to live now! julian Quote Link to comment Share on other sites More sharing options...
glang Posted July 11, 2023 Share Posted July 11, 2023 Cant see the adaptor damage is too important as long as the float chamber sits vertical.... Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 11, 2023 Share Posted July 11, 2023 Julian, High revs on start-up usually means there is a vacuum leak or the throttles are being held open slightly somehow. Nice to learn you have gotten it to start however briefly. Regards, Paul Quote Link to comment Share on other sites More sharing options...
J J Posted July 19, 2023 Author Share Posted July 19, 2023 hello all sadly the saga of my non starting spitfire rumbles on! after a lot of effort it will start but coughs, splutters and blows loudly from the first carburettor then dies distributor is new (same with the points dizzy) new plug leads pistons 1 and 4 are at the top of their stroke with timing marks lined up and rotor arm pointing to no1 post new balance grommets on carbs there is fuel and a spark Am I missing something really dumb here? I worry about timing but it seems right, I also worry about tappet adjustments but they also seem right any ideas? Quote Link to comment Share on other sites More sharing options...
yorkshire_spam Posted July 19, 2023 Share Posted July 19, 2023 (edited) The time I had a very similar issue on my Spitfire 1500 I had the plug leads in the wrong order. I'd got the right firing order 1-3-4-2, but went the WRONG WAY round the dizzy cap... (Rotor arms goes counter clockwise, I had the leads in clockwise) The effect of this is that it runs on 1 and 4 (correct timing) but mis-fires on 2 and 3 (both 180 deg out) Edited July 19, 2023 by yorkshire_spam Quote Link to comment Share on other sites More sharing options...
J J Posted July 19, 2023 Author Share Posted July 19, 2023 Plug leads are in the right positions, thank you the only parts not changed are the plugs and coil, there is a spark but if looks weak to me Quote Link to comment Share on other sites More sharing options...
standardthread Posted July 19, 2023 Share Posted July 19, 2023 Can we take it it is a twin SU carb set up? If so I had a similar episode with a Dolomite the previous owner had fitted twin SU's (don't like them, prefer Strombergs). It turned out that one was running weak, added to that a plug lead issue. So basically the engine was running on one carb. My present Dolomite (single SU) suddenly died approaching traffic lights and wouldn't re-start. That turned out to be that an emulsion had formed in the petrol (E version and I'm NOT going in to that debate again) and a globule of it had formed at the base of the float chamber next to the exit to the needle blocking the petrol flow. I blew it through from the carb end and it started first time. Then I cleaned the float chamber out and found the emulsion. Quote Link to comment Share on other sites More sharing options...
J J Posted July 19, 2023 Author Share Posted July 19, 2023 Thank you that’s really interesting. When it starts it revs high before spluttering and stopping, I guess that sounds like a carb issue as the throttle screws are backed off the plastic grommets that connect the bowls to the carbs were perished so I replaced them yesterday I bought a set of refurbished twin SUs a few years ago and have done very few miles since, I’ve been running E5 with additive since then Quote Link to comment Share on other sites More sharing options...
drofgum Posted July 20, 2023 Share Posted July 20, 2023 Julian, As I posted on 11th July high revs with the throttle closed show a vacuum leak. On the Mk3 and later Spitfires the two nuts below the inlet manifold are difficult to reach and are often found looser than they ought to be. Cheers, Paul Quote Link to comment Share on other sites More sharing options...
J J Posted July 20, 2023 Author Share Posted July 20, 2023 Thanks Paul, i checked them when you mentioned them before, I was able to tighten them a little but with no effect Quote Link to comment Share on other sites More sharing options...
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