L20 hard to start

[oldgasman]

L20 duel SU carbs runs good. But very hard to crank. ?? Starter ??

Any ideas

[MikeRL411]

First have your battery capacity checked out.  It may be at the end of it's usable life.  Most Sears stores [and others] will do this check for you.  If the battery is OK, it may just be the stubborn SU, just jiggle the wire protruding from beneath the "fuel bowl" on the side of the main body.  This is connected to the float.  Be aware, "it's not supposed to work that way" but it does.  Jiggling the float will spill some gasoline into the SU body and serves as a"prime", very useful if the car has been sitting for a while.  Try it!  It's free and just might work.  I would leave my RL411 at the airport for a week and found this to be a very good option to running down my battery on cold winter nights.

[datzenmike]

Battery terminals clean and with good quality and tight cables? What about the other ends? Is the negative cable clean and firmly bolted to the head. The positive cable to the lug on the starter?

 

Is the battery fully charged or holding a charge?

 

Is the charging system working?

 

Timing. A severely advanced ignition will fire back against the starter.

[oldgasman]

Battery mounted in trunk so u guess I would need to ground block to frame.

[Z-train]

Gasman?as in So.Cal.Gas Co.?

[oldgasman]

No not SoCal gas. Old gas as in old gas station stuff like signs and pumps

[DanielC]

"Battery mounted in trunk so u guess I would need to ground block to frame."

 

I think we found the problem.   There is a reason car manufacturers mount the battery under the hood, in most cases, even going to the trouble to put the battery on the same side of the engine compartment as the starter.  To keep the cables between the starter and battery short. 

 

If you insist on remote mounting the battery, i suggest to use AT LEAST 1/0 or 2/0 battery cables.  You can use arc welding cables.  You need to have a dedicated ground cable as thick as the positive cable between the battery, and the engine.  The frame of the car will not work reliably, because every extra connection you make adds resistance to the circuit, and every extra connection is another place for corrosion to build up and make the connection even poorer. 

 

Do you know how to do a voltage drop test? 

This is for somebody who reads this, and does not know.

Get a volt meter, connect the positive lead to the positive battery terminal.   Connect the negative lead to the lug on the starter where the battery connects.  Read the voltage while cranking the engine.  The voltage, while cranking should be less than .500 volt.

Do the test again, but put the negative voltmeter lead on the negative battery terminal,  and put the positive lead on the starter frame, or the engine block close to the starter.  Again, the voltage should be less than .500 volt while cranking.  Ideally, you want the voltage below .200 volt, on both positive and negative connections.

[banzai510(hainz)]

if still points ignition sometimes the HOT start wire is off the coil. or back of key switch no hot start to coil. wiggle.

 

timming/valave lash. intake carb tight. point ignition bushing good

[oldgasman]

What do you mean by hot start ??

[datzenmike]

The START position on the ignition feeds a direct (hot) 12 volts to the coil for fullest secondary voltage when cranking. When the key is released to the ON or run position, power is fed through a ballast resister to drop the voltage to maybe 8 volts and then to the coil. This is still enough to run the motor but it reduces the arcing of the points and they last longer.

[oldgasman]

Can you tell me wire colors for the hot start and other.

[datzenmike]

For a 510?

 

Well at the ignition switch or the positive coil terminal it's the Black/Blue wire that has the full 12 volts in the START position.

 

The Black/White wire on the ignition switch and on the one side of the ballast resister is 12 volts in START and RUN ignition positions. Note that it has to go through the ballast to get to the coil.

[oldgasman]

It has matchbox. Dist. With No. Ballast. Would it still be the same but no resistor ??

[datzenmike]

The matchbox can handle lots of current, way more than points ever could. Because of this points coils had ballast to add current limiting resistance. If you run a points coil without a ballast resister, a matchbox will draw so much current through it, it will fry.  If you have a points coil with a ballast resister it will work just fine, but you won't get the higher output voltages.  To get high output you need a coil (without a ballast) that will handle the extra current flow through it and not over heat. For this you need a stock EI coil or one in the 0.80 to 1.0 ohm range designed for use without a ballast.

[oldgasman]

Yes that is what I'm running. Just having cranking issue. Ordered a new starter to see if that might be my problem.

[Z-train]

Before you do that,get a new negative cable and route it to the starter bolt(shortest path thing).Then use a jumper from the battery to the starter to crank it. This will tell all.

[oldgasman]

Did that. Already. Same problem

[oldgasman]

Any other suggestions will be appreciated