My 2 litre, carbed Ford DOHC, which I plan to replace this winter with a zetec, is reluctant to rev beyond 3500rpm. It will, but it isn't worth it.
It is still fun to drive, as I have bags of torque, so I tend to drive it like a diesel. However, I miss the extended rev range for effective overtaking.
I haven't touched the carb since the engine was transplanted from the donor sierra. I have tried with & without air filter, but it makes no difference. It has ecu controlled ignition.
Any basics I could check to find the cause or point to either fuel starvation or something?
It has been suggested that the exhaust may be too large at 2", but I'm still using the cast manifold which gives 4:2 and then using 2" (original size) for the 2:1. Is it likely that the exhaust would cause this unwillingness to rev?

Any advice would be much appreciated

Very unlikely!!!

It is more likly to be either fuel or ignition. I would start with ignition as this is easier to check. You need to ensure that you are getting sensible advance, above 34 degrees should be OK although it may need more for best power.
If the timing is OK and the spark is good tehn it is more likely to be fueling.

Yeah , check the full amount of advance

Will it rev if you operate the throttle linkage on the carb end, are you getting full travel from your pedal setup? Does it misfire or just stop and go flat, what carb is fitted ?

[Edited on 11/8/06 by Peteff]

Doh doh doh

Just looked down into the Weber TLD carb, at the two butterflies and only the primary is opening on full throttle. I'll look further into it, but it looks like the secondary butterly is opened by vacuum, the throttle linkage doesn't connect to the butterfly, but does remove a stop to it at full pedal travel. Maybe a diaphragm is split, will check with engine running.
Thanks for the advice...
That explains the good fuel economy! 30+mpg

Yep, the Weber fitted to those has a vacuum operated secondary. Parts should be readily availble for it though, try the guy on Ebay who seems to specialise in Weber stuff: http://stores.ebay.co.uk/FAST-ROAD-CARS_Weber-Service-Kits-Gaskets_W0QQcolZ2QQdirZ1QQfsubZ3QQftidZ2QQtZkm