ok folks,what could i have done when i put my top end together to make it all ass about??have changed all ignition bits and timed it statically,done valves etc, but i still only get backfiring through the carbs.what are the possibilities?

Timing.

1. Check that the plug leads are in the right order. Print out a cheat sheet from the Kombi site at
http://www.aussiekombicampers.com/cheat_sheets.shtml 
and use it to check that your firing order is 1-4-3-2 as indicated.

2. Recheck you static timeing.

Backfiring through the carbs usually indicates that you're firing a spark plug with the inlet valve open.

hth

When I put our kombi motor together, I had this problem and it was just that I had the distributor 180 degrees out.

I had to take the distributor extension shaft thing out and change it 180 degrees.

Be very careful not to drop the washer in the case though. :thumb

thanks guys,ill have a look.although ive checked the firing order a hundred times hoping id put the leads back on wrong.helbus, where is the notch for no. one roughly pointing when your dissy is the right way?

[Edited on 9-3-2004 by franko]

When it happened to me, I found the quickest way to check if the shaft is 180 degrees out is to swap the leads as they are now, diagonally, or two places around if you like.

If it runs like that, then the shaft is 180 out. You can leave it like that, but it will confuse the heck out of someone in the future.

When I swapped mine, it started and ran straight away. I then had to turn the shaft 180, and put the leads back to make it original.

excellent!!!something i can try.thanks

you farkin legend!!!!!!started first pop as you said.ive been going mad trying to work it out.if i leave it like this do i have to redo valves?

I think if the cam on the shaft of the dizzy has a different lobe for no.3 to retard. (to alleviate overheating of no.3) Then you would be advised to go back to original.

I think also being 180 out means that no.1 does not line up with the little "l" mark on the dizzy, but 180 out also.

I suppose mechanically it helps you out, because you know the motor is not a dud.

I redid the valves the next day after the motor cooled down again. I ran it for about 15 minutes when I first got it going.

Still going now 18,000 k's later.

I would check the valves again, If you did them 180 out they will be very loose.

If you have installed your dizzy drive gear 180 out in the case, the easy way to fix it is remove the round spring off the drive on the dizzy, knock the pin out of the drive thingo and change it 180 around on the shaft, beats trying to get the dizzy drive out of the case with out dropping the washers.

Why didnt I think of that.

I was packing it while taking the dizzy drive out, because dropping one of those washers would be an engine out job if it fell right down. Yeah?

thanks again helbus,and yea dave,thanks,i think ill do that.if i stuff that up its not as bad as dropping the washer.(which id probably do).sure feels good to be back in bussiness!!!