Mk1 Nexus buyers guide?

[Taipan]

Yes and a lot quieter now the intake is sealed properly! I was disappointed to find it still pops on the overrun though? I wonder if I should disconnect the battery and let it relearn all its FI settings etc?

[michaelphillips]

good idea, i would, is the warning light still on?

[Taipan]

good idea, i would, is the warning light still on?

Yes its still on. The previous owner did say that came on when it had the wiring fault and i'm sure I read something in the workshop manual about that?

[BenR]

Yes and a lot quieter now the intake is sealed properly! I was disappointed to find it still pops on the overrun though? I wonder if I should disconnect the battery and let it relearn all its FI settings etc?

I tried to re-seal mine intake but because of the shape of it it didn't work. I'm afraid you're going to have to bite the bullet & get a new one. As for disconnecting the battery the ECUs on these aren't that clever, not wanting to be a kill joy or anything but I doubt anything will happen/change. I fitted new (second hand forks) to mine the other day & it's booked in for its MOT today so it's ready to rumble once more. Good luck with yours though & the offer of help if you need it is still there as Essex is not far from me.

[Taipan]

Hi. I used sikaflex and that sticks like mad. I can pressurise the tube by blowing into it so I the tube itself is sealed. I will still renew it though as if its old enough to perish it might go again? I assume the leak is my refitting if that is the cause of the backfiring? Interestingly the idle speed is up slightly to 1500 but seems very stable now?

[Taipan]

Ben, out of interest, was that where yours had split too?

[michaelphillips]

over run popping i thought was caused by un burnt fuel entering the hot exhaust, so the injection system might learn the new air mix once run for 50 miles or so, check that the exhaust is not leaking anywhere, do this when engine cold, hold a bit of tissue near it just to see if movement. eg downpipe both ends, to exhaust and the cylinder.
could be Throttle position sensor or Engine rpm sensor but they are all linked to the ECU so it could be the timing , the valves may need setting as they are opening and shutting slightly out, but first i would check the airbox breather pipe is not blocked, underneath the main stand there should be a pipe with a bung in the end, careful once removed as the oil in it will go everywhere if never done, so use a pot, then just let it flow, once stopped flow put bung back on, the previous owner sounds like just rode it what ever, have you removed the air filter to check its not bunged up?, there may have been oily residue under filter to clean out, these are just regular check jobs. it may just be the valve timing which is doing it and the ecu is picking it up and so lighting the warning.. a weak spark plug? try a new one just a thought,
common read below

Exhaust system backfires occur in engines that have an emission system malfunction, like an air injection system diverter valve problem, an exhaust leak, or when the catalytic converter has been removed. In some high-performance vehicles, when a driver shifts up and lets off the accelerator, the engine has a moment of running rich. This causes an incomplete burn which causes the fumes to explode in the exhaust system along with an audible pop or bang sound. This is a result of working equipment, and is unlikely to cause damage.
A fuel-injected engine may backfire if an intake leak is present (causing the engine to run lean), or a fuel injection component such as an air-flow sensor is defective.
Common causes of backfires are:
Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires

[BenR]

Ben, out of interest, was that where yours had split too?

Yes I used Sikaflex as well but the type of rubber used to make the inlet manifold didn't like the sikaflex (didn't bond). It sticks at first but after a while just comes off. The inlet is only £13 or something so not expensive.

[Taipan]

Oh I'm ordering a new one, although its gone up quite a bit and is £29 delivered from Suttons now. The skiaflex is just a temporary repair.

[Taipan]

over run popping i thought was caused by un burnt fuel entering the hot exhaust, so the injection system might learn the new air mix once run for 50 miles or so, check that the exhaust is not leaking anywhere, do this when engine cold, hold a bit of tissue near it just to see if movement. eg downpipe both ends, to exhaust and the cylinder.
could be Throttle position sensor or Engine rpm sensor but they are all linked to the ECU so it could be the timing , the valves may need setting as they are opening and shutting slightly out, but first i would check the airbox breather pipe is not blocked, underneath the main stand there should be a pipe with a bung in the end, careful once removed as the oil in it will go everywhere if never done, so use a pot, then just let it flow, once stopped flow put bung back on, the previous owner sounds like just rode it what ever, have you removed the air filter to check its not bunged up?, there may have been oily residue under filter to clean out, these are just regular check jobs. it may just be the valve timing which is doing it and the ecu is picking it up and so lighting the warning.. a weak spark plug? try a new one just a thought,
common read below

Exhaust system backfires occur in engines that have an emission system malfunction, like an air injection system diverter valve problem, an exhaust leak, or when the catalytic converter has been removed. In some high-performance vehicles, when a driver shifts up and lets off the accelerator, the engine has a moment of running rich. This causes an incomplete burn which causes the fumes to explode in the exhaust system along with an audible pop or bang sound. This is a result of working equipment, and is unlikely to cause damage.
A fuel-injected engine may backfire if an intake leak is present (causing the engine to run lean), or a fuel injection component such as an air-flow sensor is defective.
Common causes of backfires are:
Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires

I disconnected the battery for a while and then reconnected it. EML is still on. Bike seems to run better for it though? Placebo effect or did something actually change?