well she was running!

Post by **ratrodmog** » Fri May 22, 2009 10:52 pm

Hi all. I am nearing the end of my custom build and had her running really sweetly but all of a sudden she won't start, or even fire. I wired in some new rear lights and shorted them out(not earthed properly) but this wouldn't affect the starting would it? It's a 1098 with HS4 and LCB manifold. Here is a list of everything I have checked and see if there is anything I have missed or should try.
Changed points, rotor arm, condenser, dizzy cap.
There is a spark from the coil and at each plug.
Firing order is 1342 as it should be.
Fuel pump is working with fuel in the float bowl.
Good compression in each cylinder.
No blockages in the jet(brand new).

As I said, it was running but now won't even fire. Is there something else I could try?
Cheers
Ben

Post by **ssnjimb** » Fri May 22, 2009 11:04 pm

Hello

Has the dizzy been moved at all.

Check the points gap it could have closed up.

How old is the condensor it may have popped.

Are all the earth connections tight and corrosion free.

James

Post by **bmcecosse** » Sat May 23, 2009 12:10 am

Take the plugs out - and vent the engine. Clean the plugs - NOT with a wire brush (ok soft brass wire brush is allowed!) - and if possible dry them off with a gas blow torch. Then refit - and try again. But you really need to retrace every step you have taken since the engine last ran. Unfortunately you have changed some parts - and maybe introduced some problems there too!
Back to basics - make sure the spark at #1 plug is when the piston is at TDC - and both valves are tight closed! Then 1342 anticlockwise round the dizzy to the other plugs.

Post by **8009STEVE** » Sat May 23, 2009 7:42 am

After trying to start, whip out the plugs. If thet are wet, the problem is electrical. If dry, then fuel.

Post by **ratrodmog** » Sat May 23, 2009 7:20 pm

Well it seems that the plugs are dry after trying to start her but there are no blockages in the jet or float bowl. I tried squirting a bit of fuel onto the needle throught the filter but no cigar

This leads me to think electrical. Bmc, how do I check the piston is TDC? Seems strange that it suddenly happened when she was running well. Could change the coil to make sure as it didn't fire when I sprayed fuel into the needle/jet.

Post by **bmcecosse** » Sat May 23, 2009 7:25 pm

Easy way - take plug out and put finger over hole - turn engine clockwise by hand and you will feel the compression as the piston rises. Other option - put long wood chop-stick down hole and turn engine - watch chop stick rise and fall! Ahhh - so!
But to be sure it's not petrol - pour a good egg-cup full of petrol into the carb - and crank it!

Post by **ratrodmog** » Sun May 24, 2009 5:28 pm

Right, definitely not a fuel problem as I have poured a fair bit of fuel into the needle/jet whilst turning the engine over and it didn't fire. There is compression in all cylinders (put my thumb over each plug hole and it nearly pulled it off). Must be electrical. I'm going to have to gt my hands on a spare coil to eliminate it from the problems as it is the only thing I haven't changed, even though there is a god spark from the HT lead.

Post by **bmcecosse** » Sun May 24, 2009 9:09 pm

It won't be the coil! Everyone want s to blame the poor coil! they are very very reliable! Check it's actually sparking at a plug - lay the plug on top of the engine - and crank it. If spark - then test if it's hppening at the right plug at the right time ! If no spark - check back to the HT lead going to the dizzy - connect a plug to that - and crank it! If sparks - then the problem lies with dizzy cap/rotor arm/timing. No sparks - check all the low tension side of the dizzy.