Pete Lee
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Wise choice you won't loose money.
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My current spitfire has overdrive, my previous ones didn't. Wouldn't be without one now. Motorway speeds are 60 max at 4000 rpm without 70 plus cruising at 3000rpm with. My gearbox has around 80000 miles on it now no problems. I strongly suspect the overdrive is original so has over 200,000 miles on it without problems, I think I cleaned the filter when I fitted the current gearbox.
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Hi Doug, I suspect the thread has stripped, it's only a short plastic thread, recently stripped mine after 14 years, luckily I had a spare. Either that or its not on the correct slot.
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2402 wrote:The rear end should be lovely over the bumps. I've got lovely rear end suspention over bumps. Chris. Chris, I wasn't referring the the cars rear end :X Yes could be in the brackets, have you fitted polybush or rubber suspension bushes?
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I was recomended 28PSI all way round years ago, not had any problems.
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Can't say I have any steering wheel vibration, yes you can feel the road and the ride is firm especially with uprated suspension. Pot holes do send a shock through the car. On the whole my car gets better, replaced the upper steering column bush and the car felt so much more like it should. Back in the day the suspension was always "sporty", The roads of Birmingham back in the late 70's were just as bad as they are now - how we long for the past ;D. Dont expect the car to be modern, you're rear end is only a few inches off the road, this was designed as a traditional British sports car, enjoy :)
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Also search the MGB EXPERIENCE website for tuning twin su carburettors.
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932 wrote:thats how i thought they would be, but nope. currently at 33 flats out from fully in but not sure if this is higher than bridge or not, tested with colour tune today and blue spark/flame when ticking over and if open the throttle it goes orange briefly then back to blue again, cant try lifting pins as both are seized up. I think this is part of the problem, 12 flats is from when the top of the jet is level with the bridge not from the fully wound in position. If from the fully wound up position then you could be winding out by 30odd flats. You can use a drill of the correct size to lift the piston, it should be 1/16" diabetes not 1/4" as I said before. Personally I don't like the colour tune I find listening to the engine far easier and accurate when adjusting the mixture. There are some very useful articles on the mgb experience website on SU carburettors, including an excellent one by Roger Garnett.
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As I said earlier the older HS4 carbs have a different jet bearing, this is the set I am now using. The major difference to the later carbs is the dashpots. Yesterday I swapped back to the non waxstat conversion jets due to a leak. My problem with the conversion kit was a gunked up linkage causing one of the jets to stick open on choke. I set them to 12 flats as normal, tuning resulted in making them a bit leaner, less than 2mm below the bridge and slightly higher than the jet bearing. If yours are much lower then they must be too rich, I cannot see this being the result of the jet bearing. What happens to the engine speed if you raise the piston 1/4"?
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I had a thought, the jet on my conversion kit are longer than the waxstat jets. If you start with the jets fully wound up then you will have to wind them down further than the waxstat jets to get the same position for the top of the jets. Could this be your problem?
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On mine the black plastic bit is a bung, it sticks out about 0.5mm. When I set up the carbs this afternoon I started with the jet flush with the bridge in the carburettor. Turned it down by 12 flats, but I forgot to fit the pipes from the rocker cover and ended up turning the jets down much further to get it to run, maybe worth checking your breather system if you have not done so yet.
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Hi Rich, I was nearly finished when I loosened one of the pipes to the float chamber accidently, another leak so I am leaving it to another day to finish. Anyway I have a few photos that may help you. Pic one is the later carb (FXZ1122 ) damper with the needle correctly installed, pic 2 shows it incorrectly installed. The needle comes out from underneath, its secured by the screw you can see. I suspect that if the needle is proud it will bottom out, but this could prevent the piston from returning properly causing fast idle and a mixture setting imbalance between the 2 carbs. In pic 1 you can also see the piece of black plastic and 2 holes in the bottom of the piston. Pic 3 is the jet adjuster position now I have the carb set up. I do think you have the incorrect bearings for your carbs so no problem if you want to get the correct ones. On the FZX1258 carbs I have the bearing is the same as yours.
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Hi Rich, the needle moves. As more air is sucked in the damper rises making the needle rise to thinner point allowing more fuel through. So if the needle is lower then the optimum idle point is lower therefore the jet will be lower. But it can only really go down so far. I have made progress today, rebuilt carbs fitted and looks like I have got the mixture right and the carbs balanced, just stopped for a cuppa then back out to set the choke. Had a big leak though, the pipe from the jets to the float chamber needed tightening more than I had. I think the old carbs were leaking as I was finding it difficult to set them properly, but then they have done over 200,000 miles ;D