Turbo bike carby people, Help

Where is your boost gauge plumbed in? What is the fuel pressure to the carbs, and can you watch it while driving? How is the timing controlled on the Micra, distributer with vacuum advance?

Sounds possibly like the carbs have leaned out under boost pressure?

Does it drive okay without the turbo plumbed in? Maybe worth trying it again with the vacuum advance disconnected, see if that makes any difference? I think Metro turbo's had a system of retarding the ignition on boost, along with a distributer.

On my carb setup, I have the fuel pressure gauge inside so that I can watch the needle go up and down while driving. and having megajolt I can also monitor the timing advance while driving.

Did you get a air fuel ratio gauge in the end? That would give you a very good insight into how well the carbs are fueling the engine under all circumstances.

I would have thought that the signal for the fuel pressure reg should come from the plenum.

The dizzy should be fed with a pressure fitting to the vac advance unit so that it retards under boost.

On mine, the boost gauge is plumbed into the manifold after the carbs, along with the megajolt and wastegate actuator.

The fuel pressure regulator is running off a pitot tube in the plenum intake, and a second pitot tube next to it in the plenum intake goes into the carb float chambers.

You may get away with re-arranging some of the plumbing?

Typically the dizzy advance line is just a push on as it only sees a vacuum - in a turbo application it will see both vacuum under closed throttle and then boost. This could blow the line off leading to full advance and worst case detonation - so it need to be a pressure fitting - usually people use the the little push fit fittings like those on a disposable hobby welding gas bottle drill and tap the manifold and the vac advance casing. You need to check the max advance is limited to maybe 26-28 degrees and ensure that the dizzy retards about a degree for every PSI boost

Fuel pressure reg in the manifold is for injected systems where the injectors only have to overcome the extra manifold pressure

All figures engine dependent

The fuel pressure regulator needs to go on the plenum, so it can keep the fuel suppy proportionally above plenum pressure. That's where mine is fed from, and I'm sure Metro turbo's are the same.

Tried it without turbo today, carbs are leaning out at top of rev range. Getting spare jets drilled out and try again tomorrow.
I know, I need wideband sensor so exspensive !

Is next purchase

Well, as it is at the moment, thought it was turbo leaning carbs out, but ran it without turbo and at top of rev range the power dies and sounds all juttery (technical term your all unaware off)

So with me infinite knowledge (none) I have come to the conclusion (with no metering devices) I need bigger jets