Engine Doesn’t Start

[Tmac897]

Trying to fire up my rebuilt engine, but I haven’t gotten it to start. I know the whole spark / fuel routine, so that’s not my question.

I’ve got a new, fully charged battery, but the engine turns somewhat slowly. I only cranked it a few times, and only for a few seconds each try. Battery cables are noticeably warm, as is the solenoid and the starter itself. I disconnected the battery and went no further, as my automotive electric knowledge is rather thin, and I didn’t want to make a worse problem. Any guidance?

Tony

[HCA]

Yes, you have a huge resistance. Maybe/probably in the starter itself, poor engine grounding or poor live connections along the route.

[Craven]

Not necessarily anything wrong, a standard starter motor even with the correct 9 tooth pinion and a high cranking capability battery will struggle with a freshly ( tight ) engine. Remove spark plugs the engine should then spin over at good speed.

[Tmac897]

Not necessarily anything wrong, a standard starter motor even with the correct 9 tooth pinion and a high cranking capability battery will struggle with a freshly ( tight ) engine. Remove spark plugs the engine should then spin over at good speed.

Took the plugs out and it spins quite nicely. Got everything back together but still no go.

I decided to replace the coil. Even though the old one passed the resistance test, it’s almost as old as I am. So I decided to replace.

Used some starter fluid and got it to fire a few times, but not start. On to the fuel system.

[ill_will]

Hi Tony,

Have you confirmed the cam timing with a DTI or similar? And the ignition timing with a strobe (You mentioned it had been rebuilt.)

Cheers,

Will

[h20hamelan]

Before you began your restoration in 2019, was it running.

Seems to me, you might have a CCA issue?
Cold Cranking Amps is what the higher compression twink requires.
A 300 wont turn a worn engine, 500 might, 660CCA is good.

[Tmac897]

Before you began your restoration in 2019, was it running.

Seems to me, you might have a CCA issue?
Cold Cranking Amps is what the higher compression twink requires.
A 300 wont turn a worn engine, 500 might, 660CCA is good.

I technically began my restoration in 1985 with the deconstruction, then life happened. So by 2019 I guess I would have to say no, it wasn’t running. This is actually the second engine rebuild since 1985, with the initially rebuilt engine finding its way into a chicken coop in Manchester, NJ. So I guess I’d have to answer no, it was not running before this latest effort.

I have a brand new battery with 500-550 CCA, following the advice of one of the old posts on the subject. I have a 1/2 ton pickup with an 850 CCA battery, so I might try that one. I could probably stand to renew the negative battery cable. I have a new positive, but the ground connections might need some cleaning up as well. So my current predicament might be a case of a few less than optimum circumstances.

[Tmac897]

Looks like the electrical side of the equation is resolved. Starter is turning the engine normally, good spark, and the engine fires, but doesn't turn over.

So must be something in the fuel system. New fuel tank and fuel line, new fuel pump (mechanical), but it doesn’t have a bowl to see if it’s full. Weber setup for idle mixture and idle throttle are set according to spec.

Carbs are black magic to me. Anything I should be checking or looking for?

[2cams70]

Did you do what ill-will said? Usually these problems on initial startup are due to a timing issue somewhere. Typically ignition but can be valve also.

[Tmac897]

Did you do what ill-will said? Usually these problems on initial startup are due to a timing issue somewhere. Typically ignition but can be valve also.

Can timing was done with a dial indicator and a timing wheel. Static timing was done with a test light at 10 degrees BTDC for flat top pistons. I don’t have a strobe, but it should be close enough to start. I’ll check the firing order again.

[rgh0]

I would try some starter spray. If it fires and runs for a second then its probably a fuel issue

cheers
Rohan,,

[Tmac897]

I would try some starter spray. If it fires and runs for a second then its probably a fuel issue

cheers
Rohan,,

Thanks, Rohan. That’s about where I am. It fires with the starter fluid, then shuts down.

[h20hamelan]

viewtopic.php?f=40&t=54282

[Tmac897]

I was on vacation for a couple of weeks, so I didn’t advance this too much until today. Checked the carb fuel filters to see if they were clogged, which they weren’t. I found that the choke cable to one carb was not pulled through the fitting enough, so I tightened that up - but not something that should make that big a difference.

I gave the idle mixture screws another 1/2 turn to richen the mixture a little, and I sprayed starter fluid into all four carb throats.

It took a while to turn over, but I eventually got it to start. I guess the newness of the build was the major issue. Engine ran a little rough, but revved pretty easily. Good oil pressure, so that’s a big relief.

A few things to look into:
- Now that the engine is running, adjust the timing.
- Tach not working
- Make sure the timing chain is tensioned correctly
- Run it long enough to make sure cooling system is working properly.

Thanks everyone for your help.