Help please getting a new engine to start

[George Smathers]

I have just installed a rebuilt 1275 but I can't get it to start. The guy that built then engine sent me a video of it running but now that it has been shipped I am having trouble getting it to run. All the parts are new.

The starter turns it strongly, the fan goes around, oil and water get distributed but it won't start or even catch for a second. I'm wondering if I wired in the electronic distributor and coil incorrectly or if I installed and plumbed the HS6 carb incorrectly.

I have power going to the coil, the coil is grounded, power leaves the coil and goes to the distributor, and the distributor is grounded. I have a vacuum line going from the top of the distributor to the carb.

I pulled a spark plug with it's attached wire and tried to get it to arc to the block but it wouldn't. I don't see spark at all. Fuel is getting to the carb but I'm not sure what happens then. I pushed on all the plug and coil wires and I think they feel attached. Help!

Thanks,


George



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[lambrettalad]

does it spark at the king lead?do u have 12 volts at the coil?

[George Smathers]

Alex,

Good question (actually it was only a good question after I looked up our Yankee word for "King Lead"
I just checked, there is no spark coming off the King lead. That must mean I have a bad coil? It's a new Lucas unit.

Thanks,

George

[GBond]

Great looking engine George!

Try a different coil if you have one available, if that's the problem it should fire right up.

Sometimes the problem is much more basic, check there's fuel in the chamber, check the rotor arm is inside the distributor and check that the timing is set correctly (should be, if the engine ran before but it never hurts). Also check the cables are installed the correct way round.

These might seem like simple suggestions but I've had engines not start before because of simple mistakes like these.

EDIT: In your pictures, there's a brass pipe from the carburettor that's not connected to anything. I'm not too familiar with the HS4 but it might be a vacuum connection that should be either plugged or connected to a tube somewhere.

[George Smathers]

Thanks Gabriel. If I had your Dad's coil collection I would be all set!

George

[bmcecosse]

It's NEVER the coil.......it is obviously a wiring up problem - we need more details of the 'electronic' ignition. You say the coil is grounded - in what way? Why do you think that is important? Current should flow through the coil winding and be 'grounded' in the dizzy through the points - or by the 'electronics'. The video of the engine running - is it using the same coil/dizzy/electronics now? I assume petrol is flowing - but your lack of spark would appear to be the #1 problem.

[George Smathers]

Once again Roy is right; It Is Never The Coil! I knew most nonstarting problems are almost always human and not mechanical but I only learn the hard way. It was only once I had a new coil sitting on the bench that my brain got into gear. After that the engine started right up.

The problem was that I had run a wire from the negative terminal on the coil to a ground. Of course the coil could never build up charge if I was always bleeding it away. Thanks for all the help guys. Now it's time to move to my next screw-up.

[GBond]

Glad you managed to get it started, now you've got a spare coil for when it never fails!

[bmcecosse]

I did wonder about your coil being 'grounded'.... Glad you got it sorted out before the coil caught fire!

[David53]

Nice pics! What are the two relays for?

I had a similar problem when I rebuilt my engine. Turned out I hadn't shoved the lead from the coil to the dizzy far enough down into the coil and it wasn't making contact. Drove me nuts for about three hours!

[George Smathers]

David,

Good eye. The relays are for the headlamps; probably overkill but it was easy to do. I'll be posting more pictures in my Recreating Beatrice restoration thread soon.

George

[bmcecosse]

What's the 'thing' bolted on the carb intake??? Looks like it's blocking off the breather ports for the bell - and that 'double bump' won't be helping air flow either. Better to just radius off the carb inlet I think.....

[George Smathers]

BMC,

Do you mean the black spacer? My builder ran the engine and he set it up this way. I'm not sure why.

George

[mike.perry]

That is not an HS6 carb, it is an SU HIF 44

[bmcecosse]

No - you need that - it's the silvery block bolted on the inlet...... I would take it off......

[philthehill]

The silvery block as bmc calls it is the radius (or trumpet) block designed to assist the air flow into the carb. Usually fitted inside an air filter so as to eliminate the sharp corner between the carb and air filter. The two upper holes are the two holes for air to enter the bell chamber.

[bmcecosse]

Yes - I know that - but it looks like it may be blocking the vent holes to the bell - not clear if there are screw heads in the top holes - or if they are clear. It also doesn't look a great match for the carb throat either. I much prefer to simply radius the carb inlet - to minimise the vena contracta. But hardly necessary here IF that is an HIF44 (sure it's not a 38??) on a standardish 1275 - the carb air flow will not be the power limiting factor...... If it's not blocking the vents - it won't be doing any great harm - but I doubt it's doing any good !

[George Smathers]

I guess I was wrong about it being a HS6, it must be an HIF 44; I've never been clear about the difference but it a 1.75 SU carb. The engine is a built-up 1275 with considerable head work. The builder claims to have worked with David Vizard but I'm not sure what that actually entailed.

I'll play with having the radius on or off and see what works best.

Thanks,

George

[bmcecosse]

'Considerable head work' - ohhh...

[hanvyj]

The silvery thing is a stubstack, I wouldn't bother rounding the edges off the carb if you've already got one - it's doing the same job.

And no one would put the effort into machining/producing a stubstack and not drilling those holes through!