5 replies to this topic

[travellering]

My Mini has been down for far too long for me to remember the initial start of symptoms correctly.

It's a 1983 Mini 1000 with a stage one, (alloy intake, Hs4, no name LCB, cherry bomb muffler) and 59d4 electronic dizzy with a flamethrower coil. I can get it to start and sort of idle on full choke, but as soon as I touch the throttle it dies.

I currently have 3 in 1 oil in the dashpot, and the dashpot piston is slow to push up even by hand, and drops with a thunk. The plugs are coming out black, and at least one is wet, so fuel is getting in there at least.

The coil was wired correctly for input voltage, but did have an extraneous wire that I thought went to the tach on the negative side. After pulling the dash, I found it was not connected to the tach( which had never read anyway, car was converted to a three clock setup from the old 2 clock).testing found continuity to the wire that was connected to the oil pressure warning switch, so I disconnected both ends of that wire.

Unhooking that plus putting in new unfouled plugs got me from not firing at all to firing up and "woofling" a little bit at full choke. As stated, touching the throttle results in the engine dying, as does letting the choke slide in.

The timing has been set static at 5 degrees btdc, and all the rockers are moving as they should and set to the Haynes BOL clearance. No discernible change in RPM from spraying starting fluid around intake manifold, and it's been off and on again so I know all nuts and bolts are tight. Compression test is pretty consistent across all cylinders.

What else am I missing???

[travellering]

Further info, as if that wasn't enough of a wall of text. Needle is AAU, and bias spring is in and correct, pushing needle away from slot in carb piston. Spring behind carb piston doesn't have any color coding or anything I can discern to identify which one it is, but it's certainly there.

Both vaccuum inlets on carb are plugged off with brand new vaccuum caps, timing advance port and crankcase breather.

Edited by travellering, 14 August 2023 - 09:20 PM.

[coopertaz]

if all 4 plugs are definitely firing and if fresh fuel is being used would suspect air leak as you have already checked around inlet manifold have you also blocked off breather pipe, does it have servo (shouldn't on 83 but you never know) the diaphragm can fail drawing air.

[andyapanel]

Have you considered taking the top off the carb and cleaning it, the piston and the spring?
Good luck

[travellering]

I got results, from replacing the plugs yet again. Brand new NGK BPR6ES. The ones I had put in were not brand new, but they did not look terribly fouled, the electrode and post were shiny but apparently they were no better than the ones that had come out.

Still a little stumble developing after running at a constant speed then asking for more, but now it's running well enough that I think the regular tuning process will help.

Edited by travellering, 18 August 2023 - 01:16 AM.

[JamesW83]

Quick question on this to confirm, as i'm going through a similar process myself....

 

Swinging needle should angle away from the slot in carb piston? What baseline settings were you using on yours i.e from jet adjustment nut? My carb was making an awful whine when i restarted after fitting stage one kit. I had bust the inlet manifold, so hoping it was drawing air in from there, but want to make sure my carb is set up right for initial starting...