Evening All,
Thought I would put this out there to see if anyone has any simple solutions, or diagnosis options.
I have a 1380 MG Metro engine, Bill Richards Head, Kent 276, 1.5 Roller Rockers, Hif44 Carb. Lucas 59D with Aldon electronic ignitor kit. Facet silver top fuel pump mounted on rear subframe, feeding filterking filter/regulator mounted on engine bay bulkhead. Have had it rolling roaded at 105bhp @ 6250rpm, and really pleased with it.
Did the track day at Brands last week, and it went well, to start with!
Toward the end of the session, I noticed that it lost power/went flat at high RPM. I struggled to get it to rev over 5500rpm in either 3rd or 4th, but would pull well up to this RPM. It had been revving to 6000/6500rpm earlier on in the evening, and was still pulling!
I wasn't sure if this could have been a temp problem, but if anything, it was running a little under "N" on the gauge, I have since taken it out on the road, and it's still doing the same thing, so a prolonged track day wasn't causing it, it's there all the time.
Can anyone think what the cause might be?
Have done a compression test, results were:
1- 225psi (plug mostly brown/beige) UNADJUSTEDNONRAW_thumb_38c2.jpg 42.37K 10 downloads
2- 225psi (plug brown/beige with a little sooting) UNADJUSTEDNONRAW_thumb_38ea.jpg 42.79K 6 downloads
3- 235psi (as 2) UNADJUSTEDNONRAW_thumb_38eb.jpg 40.95K 5 downloads
4- 230psi (as 1) UNADJUSTEDNONRAW_thumb_38c1.jpg 42.8K 3 downloads
I have attributed cylinders 2/3 having a little sooting due to running slightly richer than the end two cylinders, a common mini problem, but none appear to be white, making me suggest mixtures are generally OK.
Have ordered a new coil, to rule out coil breakdown at high RPM, is there any way to test this apart from fitting the new coil and road testing again?
Thanks in advance!
Howard