Recently my 1970 Jaguar Series 2 has developed a carburetor problem. I assume that one of the jets in one of my carburetors is stuck. It began idling at 20,000 RPM's. I am hoping I don't have to have the carburetors rebuilt. Does anyone know of an easy fix for this situation such as something that could added to the gas tank? At first I thought the choke was stuck but that's not the problem. Recently the RPM's are increasing up to 30,000 RPM's . Any thoughts?

 

I assume you mean 2,000 and 3,000 rpm! Before you start taking the carbs apart, I'd look at the linkages to see if they are sticking. Work your way from the bulkhead all the way down to the carbs. Can you manually reduce the revs at tickover to normal levels by tweaking the linkages?

 

No, meant 20,000 initially and now it has increases to 30,009

 

Don't mean to be picky, but it can't be 20,000 and 30,000. You wouldn't have an engine. The red line ends at 6,000 for a series 2 4.2 litre, with no revs indicated past that number. Nonetheless, I think your point is that the revs are sticking at too high a level. Have you tried manually moving the linkages under the bonnet at tickover as I suggested above?

 

Thank you for your advice, that's exactly what the problem was. Apparently an adjustment screw for idling had moved and caused the problem.