'73 Eldorado turning over real slow when hot.

[SmokyBC]

So I'm late to,the party with my MG this season, other bikes have been keeping me busy.

But with new gas, and a charged battery, it fired right up, and away I went. Topped it up with no methanol gas and went for a ride. Re-starting it hot, it turns over slow, and is hard to start.

At my friends, it wouldn't start, and we had to jump it.

Once home, it shows about 12.3 volts idling, and 13.5. When revved up. But both those numbers jump a round a lot.

I've only got about 150 miles on new Gilardoni barrels and Pistons, so it's still tight.

Anything I can change or check?

I should have done this in the Spring, damn this is fun to ride. 

[Cam3512]

How old is the battery?  Might be time for a new one.

[Red Dog]

Just a general rule of thumb I have lived buy:

Electrical start at the source.  So check the battery with a real load meter.

Starters fail when hot

Batteries when cold.

If batt checks good then see how many amps the starter is drawing or just pull it & clean it.

[Kiwi_Roy]

Measure the Voltage at the starter while cranking. If it's low don't automatically blame the battery.
Measure across the battery terminals, not the lugs, the actual posts on the battery while cranking

Compare the two readings
It might be as simple as a loose battery connection or ground.

They are fun, aren't they

[rodekyll]

What bike?

Also go back over the baseline -- valve adjust and (if applicable), timing.  If your dizzy advance is sticky it will be hard to start either cold or hot depending on where it stuck.

Starters can have both electrical and mechanical issues that cause them to turn slowly or not at all.  A quick check would be to borrow someone else's and see if the problem follows the starter or the bike.

That's all I've got.

[Antietam Classic Cycle]

Might be time to service the starter.
http://www.thisoldtractor.com/moto_guzzi_loopframe_starter_and_solenoid_repair_-bosch-.html

[Tom]

 :1: with Charlie.  The internals for the starter need corrosion cleaning.  One overlooked item is the negative ground for the battery cable.  Make sure that it's clean and corrosion free.

[SmokyBC]

OP here.

Battery is a year old.

I rebuilt the solenoid last year.

I'm going to pull the starter tomorrow, and clean it all up. I'll report back with my results.

[John Ulrich]

Time to retorque the heads, set the valves.

[SmokyBC]

So I pulled the starter, cleaned it up, brushes looked fine, and gave it a dab of grease. Then painted it shiny black.

Sadly it still turns over slowly when hot, but it starts every time.

Next I'll do an amp draw check on the battery. I really thought that new paint would do the trick! 

[normzone]

I really thought that new paint would do the trick! 

I don't know why it wouldn't, I'm one of those lucky guys who's machines run better after I wash them.

[Kiwi_Roy]

Dissable the bike so it won't start, plug leads off or similar

Take a Voltmeter and connect it across the starter from the large brass stud to chassis
Measure the Voltage while cranking

Take the Voltmeter and connect it across the battery posts from Positive to Negative (note,  across the actual posts of the battery)
Measure the Voltage while cranking

Get back to us

[twowings]

"Battery is a year old"  Year-old does not equal new  New does not equal good.  Load test the battery and inspect battery cables.

[Kiwi_Roy]

"Battery is a year old"  Year-old does not equal new  New does not equal good.  Load test the battery and inspect battery cables.

That's what I'm asking him to do above, load test and test the cables 

[SmokyBC]

Kiwi, I,will do that in the morning, and report results.

Thanks

[wymple]

A lack of fuel while cranking a hot engine will give you that exact symptom. Prime it a touch with raw gas when hot, if it rolls over once slowly and then picks up cranking speed quick, I'd bet on the fuel issue. However, it's most likely an old starter issue.

[SmokyBC]

OK! So here are the results of the voltmeter/cranking test.

At the battery, at rest, 13.05 volts, with key on 12.8V. I have a headlight switch, light was off.

Measured at the battery, while cranking 10.9V

Measured at starter with key on 12.4V, and 10.7V while cranking.

Put the plug leads back on and it fired right up, no choke.

I could do this again while it is hot and see what the results are, what say you?

[Tom]

Can you load test the battery?  You need to do that first to eliminate the battery from being the problem.  Lead acid batter or ?

[Two Checks]

Heat is also an enemy of batteries. As others said, test it.

[Kiwi_Roy]

Measured at starter with key on 12.4V, and 10.7V while cranking.
 
I could do this again while it is hot and see what the results are, what say you?

10,7 while cranking is pretty good, it must have been spinning ok.
From the other readings you took the other connections are fine.

Yes you could try it again hot.
Maybe open the starter up, look for any sign of the armature being polished by rubbing on the fields, usually a sign that the non drive end bush needs replacement.
New brushes might speed it up a little.
I like to dab a bit of molly grease on the ring gear, it helps it spin over a bit easier.

If I remember I will do the same test on my Eldorado this evening.

[LaMojo]

...I've only got about 150 miles on new Gilardoni barrels and Pistons, so it's still tight.

Did you measure the piston/cylinder clearance and ring end gap before installing?

[SmokyBC]

Yes, rings and pistons installed to spec.

I'm taking the big bike out for a four day jaunt thru BC, MT, ID and WA. I'll settle this when I get back.

[Kiwi_Roy]

I believe the Giladoni kits come all pre-gapped, at least mine did (last year)

[Tom]

Smoky....you get any where near an Advance Auto, O'Reilly's or Checker.  They'll load test the battery for you for free.  They have sealed lead acid batteries with high CCA's. 

[Kiwi_Roy]

I remembered to test mine, recently restored cylinders

Lucas starter with solenoid underneith
Wall Mart battery ES14BS Start 12.76 Volts
While cranking drops to 11.2 Volts
Spinning over (or cycling) 25 times in 10 seconds

Even after leaving the light on for over 10 minutes it still cranked at over 11 Volts.

[jrt]

Timing too far advanced?

[chuck peterson]

I Had similar on a v700, but it was Marelli strter....took the starter to a basic starter/gen/alt shop...all rebuilt and working perfectly, about $125....
Problem disappeared, took back two more...they loved having something "different" to work on...helped that the owners father drove a Falcone in the home country...

[Furbo]

My guess, you need a new starter, or someone who knows what they're doing to rebuild yours.

Wiring builds up resistance over time, heat exacerbates it.

[SmokyBC]

UPDATE

So the bike is starting fine now.

It wasn't any single things, but taking all of your suggestions, combined they have the bike running fine, and starting easy.

Cleaned the starter, set the ignition timing, and after putting on 500 km since the new barrels and Pistons, I re-torqued the heads and set the valves.

Thanks for all the help.

[danedg]

Don,
As you are finding out, these things shake like a wet dog and have a tendency to loosen fittings. A small container of LocTite is always in the kit. Don't just eyeball the battery ground cable, grab it and wiggle. You said the meter was bouncing around and that could indicate a loose battery connection. I ended up moving the location of that connection from behind the battery to another bolt that connect the tray to the tranny.
Double check the spade terminals on the starter relay, they can get sloppy from all the bouncing around.
And keep an eye on your exhaust header nuts. The right one is especially prone to loosening.