hi all, just looking for some suggestions on what could be happening to my #3 cylinder.

its been a few times now that my 68 bug goes from running beautifully to running awfully. when this happens, i take out the plugs, check them, clean them and put them back.
every time i do this i notice that plug #3 is coated in oil and carbon deposits, but the others are fine.

after i do this it runs fine again until the next time.

i have taken it to a mechanic and they cant tell me what is wrong. Perhaps you all might have some ideas?

thanks in advance

Is it oiling up from oil? or form fuel? also what carb setup are you running? duals? or single. I used to ahve major problems with all my plugs fouling, went to NGK irridium and haven't had a problem yet.

Ask the mechanic to do a compression test, could be a broken ring causing oil to foul plug or worn valve guide doing same

If compression is down on that cylinder then it might be time for an engine over haul

it looks like its oiling up from oil... very black and oily smell.

im running a mid-mount weber 40dcn, dual port 1600 type 3 engine conversion.

the first thing the mechanics did was a compression test and all cylinders are fine.

i used to have the same problem on my 1600tp I thought that it may of had something to do with the fact the #3 is retarder (i think or was this earlier? ) anway I switched over to twin carbs and a 009 + a service and it has not done it again ... wierd ... I guess make sure your timing is right as if you running to cool the plug wont get a chance to burn off the crap

What type of plugs are you using ??? did you try a plug from a different cylinder... some of the Bosch plugs where crook a little while ago,

If compression is ok, my bet is poor ignition on that cylinder. plug, lead, cap, dizzy.........

new plug, and change the lead and cap for another one. Check that the dizzy is working correctly too.

You *can* have good compression rings but shagged oil scraper rings too. Look at any laser/323 of '80s vintage. Great compression but smokey as a smokey thing.... Does it use oil Starbug?

kkk

okies, a few more observations.

the leads are brand new, same with points and the cap. when i last got it serviced they fixed/changed all that and made sure the dizzy was working. that was about a month ago.

ive noticed that the manifolds on the 1&2 side get pretty hot after ive been driving it when its running like crap, but the manifolds on the 3&4 side are quite cool.
when the car is running fine both manifolds are the same temp.

car is thrifty on oil, only need to top it up a little bit every so often (maybe once a fortnight?) oil change every 3 months. it doesnt blow smoke.

could it be due to one side of the weber running alot leaner than the other side? i remember this was an issue with the bug last year when i got it serviced...

and im using bosch plugs. they wouldnt be more than 2 months old.