Still not getting better. I dunno if there might be something wrong inside the engine i.e. a pushrod or something.
It's been getting a little worse. Very noticable spluttering going uphill at 1/2 or more throttle. It's also chasing up/down a good 150rpms or so at idle, esp. with the choke engaged. I'm wondering if it could be the renix or if the fuel supply is getting cut off..
If anyone else thinks it could be the renix I'll find another one and try that.. but i dunno. Anyone else had a failing renix? I'm guessing this cause cyl #3 doesn't run right.
This engine's been giving me a bit of a headache lately Been struggling with an exhaust "leak" for too long too only to realize it was noisy due to the exhaust hitting the right leaf spring.. welded on a short bend and it's now really nice and quiet. And i've screwed around with that exhaust for days only to find out it was this simple
sorry to join the party late but reading through where you have got so far I agree the next check is an air leak for that one cylinder. plug, leads and cap are all ok and if the renix output for the plugs was weak it would affect all plugs (as per Michol's car which had weak spark and eventually stall and would restart - due to high resistance on coil connection (9and 10 I think in green book?). Have you tried a propane spray to locate or confirm the leak? From experience, an unlit blowlamp works well in this case. you might need a high flow rate though to ensure the propane does disperse too much before reaching the leak. If you have a leak, propane will be sucked into gap and engine revs will rise.
Well in Norway you can buy something called "Start gas" which you spray into the air inlet to make it easier to start in -40 degrees celsius.. probably the same stuff as carb cleaner. This works for finding leaks.
I think there is a leak somewhere, but taking the inlet manifold off just isn't very tempting, and i dunno where to find a new gasket?
Hope it's the inlet manifold gasket though, it would be a huge relief to have my baby running again
Well i dunno, still struggling with it tried to take it for a long drive today on the freeway. It runs okay i guess a little rough but after driving steady especially uphill for a while going 55mph or so steady for a while it just dies and i have to sit a minute or two before i get throttle response back. Too rich mixture i guess i need to sort that out first.. I've given up on it i don't have time for all this.
My GF recently passed her drivers test so she's driving it a little bit no more than 15 mints or so at a time though, as i said i took it for a half hour drive to work today and it stopped twice. I know the carb should be adjusted properly but i think there's more to it than that, but it's got most if not all the symptoms of rich mixture.. starts easily cold (minus 5 celsius here starts easily with a little choke), hard to start when warm, splutters and generally screws up.. I'm gonna do a ghetto adjustment tomorrow of the mixture ETC and see if things improve somewhat.. check on the plugs maybe for soot.
Well i replaced the space age tube (the preheater air hose) to the carb, and tried adjusting the fuel mix per the instructions in the sticky thread here, but i can't make the idle RPM go down below 1200 or so with the mixture all the way out. Probably the air inlet flap stuck on cold engine setting? I just adjusted idle as far as i could down (a little more and the screw would pop off i think) and adjusted the mixture till it just dropped off 50rpm or so.
Engine ran perfect on full choke now when cold (before adjusting the carb), and ran OK when warm (after adjustments). Next cold start will be interesting, hope it's ok
had similar prob recently and seemed to affecy only ni 4 plug.and traced to road dirt on the king ignition terminal and lead to the renix . Was holding moisture in this damp weather
Been struggling with an exhaust "leak" for too long too only to realize it was noisy due to the exhaust hitting the right leaf spring.. welded on a short bend and it's now really nice and quiet. And i've screwed around with that exhaust for days only to find out it was this simple 
