Engine Missing
Hello All this is driving me mad . I lent my car to the wife (1st mistake), she filled it with Optimax and drove it or a week – comes back with a miss – it is fine or not noticeable under load but at idle or cruising in 4th it is a constant –I have checked most things – plugs, points, tappet gap , wires to carbs, timing etc but cannot find it.
Any ideas ? IT is a dual port standard twin carb type 3
Paul

Hey Paul,
Try pulling out your idle jets and making sure they're not blocked. had this problem with the square and it was a bitch till we worked it out.
Steven

At idle, disconnect each HT lead in turn. If you're a wooss like me & are afraid of a HT shock use a work glove but connect it (the glove) to earth via a lead & a couple of croc clips- trust me- it really works!
You'll find that disconnecting a "good" cylinder will drastically affect the idle-ie make it go real slow. Disconnecting the bad one will logically have no effect on the idle. Then go thru the electrical side with a fine tooth comb.
Start at the HT terminal on the dist cap- look for arcing signs or cracks internally. Look where the HT plugs into the cap- is it clean or sooty. Check the HT lead to the cylinder by replacing it even temporarily. Is the plug connector ok? Maybe trim a bit of wire off the plug end & then screw it back in. If you have new plugs, then that should be the end of it. If it's still missing, it's bad news & time for a compression test.
Good luck!!

Your engine is missing? Maybe she sold it!

Seriously, though; I'd pull the plugs and see if they're fouled. That's about the only thing that could be related to the fuel.

Thanks for the help guys - have done some of that stuff but will look into the rest.
Funny how some engines never play up and others just like to test you

Cheers Paul

Yeah.

All cars are female - but some seem to think they're married to you.

hey when you locate the cylinder thats missing, pull the hi tension lead from the top of the dizzy. Start the engine in the dark somewhere and look to see if there is a spark arcking anywhere...perhaps on the lead from the coil to the doghouse? i'll bet thats you trouble.

Optimax has stuff in it to help "clean" so i hear. I have had trouble with it disolving shit and placing it in my idle jet..very uncomfortable....take it out and spray and blow it out....

easy starting point anyway

Thanks people
I have decided to wait untill my new webers are on it that will at least eliminate carb issues.

Cheers Paul

Funny though it was purring before the Optimax