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rolex748
13-Sep-2009, 15:34
I Have a 99 748 Bp with 21k on the clock.

It has 45mm Termi end pipes, Carbon Airbox & Tubes with JHP Air Filter. I have also have the correct chip in the ECU.

However I have also fitted a Lighten Flywheel.

My problem is that, once the engine gets hot, eg after 30 miles I can feel the engine lurching, eg speed's up and then returns back.

If I pull in the clutch and coast to the junction it will stall.

Is this problem the cause of the flywheel or something else?

Once the engine is hot, just as you open the throttle, it seems to split through the bell mouths, not loud but there.

The throttle feels like the cable is fraying or catching on something and then seems once the revs rise completely normal.

I suspect the throttle bit is a red herring, but will inspect later today.

Any help would be handy.

skidlids
13-Sep-2009, 19:13
Possibly the throttle position sensor needs resetting
Sounds to me like your running a bit weak on the mixture, OK when cold when the trim factors from the air and water temp sensors add a bit of extra fuel but once warm theyr'e not adding anything

Airtractor
27-Jun-2020, 07:43
I have the exact same problem with my 748!! Did you find out what the problem was?