Hey everyone, i finally got my head converted to unleaded and skimed for £140 quid in the end. Ive put it all back together, got it started and it drove it round the block which was a bit ropey! I adjusted the valve clearences when the engine was cold and didnt get a chance to readjust when hot as the manual says. Today i went to start it up to get it a bit hot so i could adjust them properly and it started for about 2 seconds and then a puff of smoke came out the carb!! Didnt dare try again, any ideas whats wrong guys?
carb smoke
- Thread starter alexlambe
- Start date
Probably a back fire, pre-ignition. Have you adjusted the timing at all. Daft question but did you use the 'rule of 9' when you adjusted the valve clearances - No1 valve fully open/adjust No8 - No5 valve fully open/adjust No4 etc. If you have got them too tight a valve could be held open and if it is an inlet valve it could result in white smoke back through the carb. Another thought - did you grind the new valves in before you assembled everything so they will seal properly.
'Harvey the RV'
'Harvey the RV'
its not uncommon for engines to spit back in the carb, especially when cold. as panky says a tight tappet or dodgey valve seat will easily cause it. try it again and see how it runs, it needs chance to settle down again 
"you were only supposed to blow the bloody SLIDING doors off"
"you were only supposed to blow the bloody SLIDING doors off"
Hi Alex,you are not far from the "cambridgeshire meet" would you like to join us? see post under chat [}]
Sybhil & no1
]Sybhil & no1
Cheers guys, i adjusted the valves correctly and the guys who converted it to unleaded did all the valve work and are well known in my area for work like thios so i doubt they mucked up grinding them in. I got a mobile mechanic out today as i was getting out of my depth and yep, it was a backfire in the carb, i had knocked the distributor aparently and he adjusted it and no more backfire. It was runing ropey because the new points i put in from Speedy's were faulty and were to stiff. They werent closeing how they should have been and as a result it was missing beats, he found and rectified this problem by puting the old ones bac in. One more problem now, he is coming back on thurs to look at the carb, it has been replaced to a webber one at some point and works fine at high revs but at low revs it keeps making the engine cut out. He didnt have time to properly look at it tonight but said to me to check the gasket and little holes at the bottom or something before he comes back. If anyone has any other ideas what to look for (and if anyone has actualy read this far ) ill give it a go. Commerchris, sounds great i may pop along on the sat for a few hours depending on if im not working and my van is runing!
) ill give it a go. Commerchris, sounds great i may pop along on the sat for a few hours depending on if im not working and my van is runing!