Hi all coming to the end of my engine rebuild. Can't get bloody thing to start.
I'm reasonably confident the engine is timed correctly. Made 2 marks on cam sprocket, bisected angle and set that with E.P mark on flywheel. Set to 6 degrees and stationary time dizzy to go bang. Fresh fuel, bloody thing won't go.

It sounds quite chuffy when it's turning over. Both rockers have the clearance required when at TDC so confident it's on the bang stroke.

I can't work it out.
It ran before the rebuild.
Any ideas?

Have you done a compression test since thr rebuild?

I've found in the past engines that wouldn't start, solved in the end by pouring a little oil into the cylinders to help seal them.
It worked and once started ran without further problems.

Do you have a mechanical fuel pump?  If so, is it set up properly with the cam shaft?

I didn't have mine set up properly and had issues as well.

Is there a spark at the plug and fuel at the carburettor?

Quote from: Alan Drover on Mar 04, 2024, 05:34 PMIs there a spark at the plug and fuel at the carburettor?

Yeah have both I think compression test is next, make sure everything is hunky dory in there

Quote from: Larry S on Mar 04, 2024, 05:17 PMDo you have a mechanical fuel pump?  If so, is it set up properly with the cam shaft?

I didn't have mine set up properly and had issues as well.

have fuel pumping fine! Fuel was a bit old so have fresh fuel as well.

Distributor in correctly/spark plug 1 is getting the spark from the dizzy cap at the correct time?

Quote from: Chris866 on Mar 04, 2024, 06:24 PMDistributor in correctly/spark plug 1 is getting the spark from the dizzy cap at the correct time?

As far as I'm aware! Static timed it at the 6 degree mark on the flywheel! I use a light that goes between lead and plug and she lights up fine

I think I'll do one thing at a time. First I'll test compression! I'll post results 👍🏼

Are the plug leads connected to the correct  plugs?

The timing could be 180 degrees out. Was number 1 cylinder on the compression stroke when you timed it?

is the cam shaft correctly timed? Did you replace the cam sprocket with one of the single slot, or keep the original?

Quote from: Alan Drover on Mar 04, 2024, 08:43 PMThe timing could be 180 degrees out. Was number 1 cylinder on the compression stroke when you timed it?

So easy to check ...

If you had the distributor drive out while doing block work so easy to put in in 180 degrees out 
Very hard to spot.
Very hard to remove and reset - you have to remove the oil filter housing to get at the grub screw.

 -25D

Quote from: Wittsend on Mar 05, 2024, 11:01 AM

Quote from: Alan Drover on Mar 04, 2024, 08:43 PMThe timing could be 180 degrees out. Was number 1 cylinder on the compression stroke when you timed it?

So easy to check ...

If you had the distributor drive out while doing block work so easy to put in in 180 degrees out 
Very hard to spot.
Very hard to remove and reset - you have to remove the oil filter housing to get at the grub screw.

 -25D

I did have dizzy drive out but as far as I'm aware it's correct! The distributed arm points at number 1 cyclinder when on compression, got it static timed at 6 degrees so I can't see how it can be? Or am I being daft? After TDC on flywheel, it hits E.P and the exhaust valve is fully down. Then intake opens on way down. Both close and you're back on TDC with arm pointing at 1 and it sparking. Compression test tonight I think... make sure I've not done something weird