Discussion
My newly acquired 1600VX '99 has a flat spot!
One would assume that the Webers would be correctly jetted from the works for this power unit.
On that basis I removed the tops to check the accelerator pump circuit of both carbs. Both mechs are working fine with fuel being pumped into the four jets (which are all clear).
The flat spot is at low revs say 1500ish then clears. Is this a "characteristic" of these 40's or something else? It idles/starts ok
I'm loathe to put it on a rolling road as it puzzles me as to why this occurring. As mentioned above I am intrigued by why I would need to re jet a set of original carbs when the motor has no mods at all. In fact the car is totally standard from new factory built. Is it some kind of emissions thing? It would seem unlikely that the idle setting would cause this. I could get a Gunson colourtune to perfectly set up each choke correctly or an air synchroniser. But that would seem to be wide of the mark.
I welcome your thoughts.
A pic for your peruse for the enthusiasts. I'm quite impressed actually with my first "poverty spec" Caterham. I like the Weller racing steel wheels as opposed to the usual superlights. I think after this season (I intend to go to the Cote D'Azur in it avec doris) I will sell it to get a sigma engined example. A pin sharp drive and classic feel really lift the spirits!
One would assume that the Webers would be correctly jetted from the works for this power unit.
On that basis I removed the tops to check the accelerator pump circuit of both carbs. Both mechs are working fine with fuel being pumped into the four jets (which are all clear).
The flat spot is at low revs say 1500ish then clears. Is this a "characteristic" of these 40's or something else? It idles/starts ok
I'm loathe to put it on a rolling road as it puzzles me as to why this occurring. As mentioned above I am intrigued by why I would need to re jet a set of original carbs when the motor has no mods at all. In fact the car is totally standard from new factory built. Is it some kind of emissions thing? It would seem unlikely that the idle setting would cause this. I could get a Gunson colourtune to perfectly set up each choke correctly or an air synchroniser. But that would seem to be wide of the mark.
I welcome your thoughts.
A pic for your peruse for the enthusiasts. I'm quite impressed actually with my first "poverty spec" Caterham. I like the Weller racing steel wheels as opposed to the usual superlights. I think after this season (I intend to go to the Cote D'Azur in it avec doris) I will sell it to get a sigma engined example. A pin sharp drive and classic feel really lift the spirits!
Edited by P50 on Sunday 29th May 06:12
Why do you not want to put the car on a rolling road? My car had a bit of a flatspot when pulling away as well as a petrol leak from 1 of the 40's, I took it to a weber specialist who put in new needle valves, a missing plate, hence the leak, new petrol pipe, a few dyno runs and after he had checked plugs, altered timing checked valve clearances the car produced an extra 6hp and no flat spot! All for £192 so the price of a service really but I know that engine is spot on!
The carbs needed no adjustment even though the chokes are bored out!
The carbs needed no adjustment even though the chokes are bored out!
Gassing Station | Caterham | Top of Page | What's New | My Stuff