running rough | 2.25 petrol

hi all,

so i have the current problem that my series 3 isn't running as good as it was before ...
It idles quite fine but won't accelerate/go up in revs like before :/

Maybe it is running on 2 cylinders ???
The ignition is set at 7°BTDC as she is running on 95 octane fuel + additives .
It has the 2.25 petrol (8:1) engine with a new weber 34 ICH fitted .
compression test showed :
1. 125psi
2. 125psi
3. 137psi
4. 126psi

Thank you for your helps

Is 7deg static or at idle? Static would be bad.

Compression seems a bit low but not that bad. Tappets? How you changed anything recently or has it gradually got worse?

hi there
timing is set with a test lamp ( made out of a used s3 brake light ) at 7 ° btdc. made some road test and there was a power difference from the TDC.....

i suspect a carb issue , maybe a blocked jet ??? what do you think

i havent't changed anything from where it ran very good , it just started running bad one day

That seems quite advanced but if you think it runs better...

Blocked jet is possible but seems unlikely, though cleaning out the carb can't hurt. If you suspect fuel, what about fuel pump, fuel or tank pickup?

Yes i forgot to mention that fuel supply is working well (new pipes+pump)

i had a look at the air filter , is was full of dirt -.-
while the engine was running , the filter was diconnected

i think i will have a closer look at the carb and clean it then once i get the time
thanks anyway

Try starting the engine and with it running block the air intake with you hand this can often clear blocked jets. Worth a quick try rather than full strip out.

hi Blackburn
in fact i had already taken the carb out at that time , but thankyou anyway
i have cleaned it now and have put it back together , just need to order some parts as choke cable won't pull and a piece of metal from the throttel linkage snapped....

i hope a cleaned carb will correct this issue