I'm in need of a good spin

[Steptoe]

here we go, 2 identical 11's side by side in the shed.
740 goes like a bat out of hell, 516 also goes like a bat out of hell----once you get the thing started----it has a very laboured wind over.
Have cleaned & polished the starter brushes, windings, commutator, planatries, & shined up all earth & contact points.
Still the same, soooo, swapped starters, 740 starts great, 516 not so, swapped start solonoids, 740 great, 516 same.
Soooo pulled the BATTERY out the 350 full alloy V8 [660 CCA], straight onto the starter cable, earthed directly off the starter, you guessed it, still the same, soooo swapped every thing over again with the big battery, 740 still turns over normally with all of 516's parts but 516 is getting closer to the scrap metal dealer by the second, almost forgot cables have been deleted from the equation as well.
Once 516 is running there are no issues, spark is strong, there are no charging probs, no missing, the only thing that could be a very long shot is the fact that there is no ballast resistor to give the coils their 6 volts to start,but if that was an issue, 740 would be the same--maybe--
Idea's will be great please, thankyou, ta
Have been working with these machines for 16 yrs, now am at an end with this problem, any idea's ?

[ozlad]

Hey Geoff is this a new one that was of ebay down ther? or the one you told me about...... sorry no idea on your problem though

[dbeardslee]

You mentioned not having a ballast resistor. The ballast resistor and the coils go together - if you've got the 81 style coils (3 ohms) you don't need it. If you've got the 78-80 coils (1.5 ohms) you do. You can tell the difference by the length of the high tension wire tunnels. On the earlier models the tunnels run the length of the coil. The 81's have one long tunnel and one short one. I don't know if mismatched coils would cause or contribute to the starter problem though.

[Steptoe]

81

both bikes are original, 516 more so, even still has showroom dust on her, plus an extra 28yrs worth. She's not mine,am trying to get it running for a mechanically challenged fella.
Apparently it has been hard to start for a good many years, he doesn't even try to start it in winter.
Hi Jim, yes it's the OTHER one, I didn't promise the guy anything, I said I'd have a go at it though.

[oseaghdha]

I would take a torque wrench to both of them and see how much ass it takes to spin them by hand.

[Ivan]

Am I correct in thinking that you used the car battery and bypassed the solenoid? You say you have switched out all the components at one point as well, correct?

The only other suggestion I have is to load test the system. If you have a load tester, hook it up to the starter cable (unhooked from the starter) and the case near the starter. Hit the start button, and crank up the amps until it falls to 10.5V, and if you have a good amount of amperage, then it almost has to be internal engine drag.

Maybe one other suggestion, is the starter casing making good contact to the engine case? Paint or corrosion getting in the way of electrons?

I know some of this is elementary, but even after being an auto tech for 10+ years, the stuff that stumps me is the basics.

[CatatonicBug]

I dunno if I really uderstand the problem correctly, but what I read is that you know it's not an electrical problem, and once you get it started, everything runs great. My first thought is the jets down IN the float bowls. That's where the fuel comes from when starting, and if they're clogged, fuel has a really hard time getting into the engine until the engine is actuly running and the pilot jets kick in. HTH

[Larrym]

Resistance is Futile.

It's great to have another working model to exchange parts with. But if exchanging the parts didn't lead you to the defective component/connection then you're stuck with guessing or chasing your own tail.

Here's where a little used but essential piece of test equipment that not everybody owns will come in handy: Inductive Ammeter. I've got a cheapo that I got at "Pep Boys" for about $15.00. One lays the wire inside a metal channel on the ammeter and the meter will read how many amperes are flowing. (The meter has two channels: one large one for large cables like for a starter and another smaller one like for testing charging current.)

If you use the inductive ammeter on both bikes then you might see a difference in the starter amperage "draw". If the reading is lower on the problem bike (516) then it is likely that there is still some resistance somewhere which makes the starter run slowly. If the amperage reading is higher on the problem bike (516) then the starter is having to work harder due to some mechanical drag.

Cleaning the grounds and connector ends is a good thing but it is also a possibility that the "cable end to cable" connection is iffy. This would not show up in a resistance check with a multimeter until it was so bad that almost no current would flow in the cable. But an iffy connection like this generally only shows a problem when the high amperage demand is made and the connection voltage drops due to high load and limited flow of those little electron guys.

[Steptoe]

where to go

Hi Ivan, if we're looking for internal drag what's the start point? the starter clutch maybe, the turns easily with a spanner on the crank end with no unusual sounds.
Or do we go in from the clutch, highly unlikely a small shaft would be dry on the starter gears?
All contact area's have been cleaned.

Catatonic, carbs have been stripped down, cleaned, blown out with 120 psi air & checked over with several defects rectified, suppose the only way to rule fuel out would be to swap carbs as well [to much more of this swapping I'm going to start forgetting what goes with which]

Larry, hi, is the Ammeter a tool of today or was it used yester year, will try to hunt one down shortly[auto shops don,t open 24hr's any more]

I'm sure these bikes are alive sometimes, they test you like a 6 yr old

[Larrym]

Today's Inductive Ammeter

Steptoe,



Available at NAPA or their online catalog:

http://ecatalograck.genpt.com/pdfcat...ch&leftpanel=0

Not as accurate as the Inductive DC Amp probe that goes on a digital multimeter but it doesn't cost over $150.00. Good enough for car and bike starting/charging systems.

[Ivan]

Is it possible your ignition timing is advanced too far on start up? That would cause hard start but run ok when finally going?

[Steptoe]

Time of death

3:30 pm 20/10/09
there is only so long you can work on something that doesn't want your help.

Have been working on it all day, as the day has worn on spark has been getting weaker to the point of barely there.
One advantage to being a horder is accumulation, so back to swapping stuff, firstly the timing pickup spark exciter vacuum advance,,even weaker spark .

Left the new pick-up assy in and changed TCI box still winds over slow,now WITH NO SPARK AT ALL, swapped all cables still winds over like it has 2 'D' size batteries instead of SIX HUNDRED & SIXTY CCA .

It's not that it has no spark or that it won't start, but having a battery that turns a motor 5 times it size something is terminaly wrong, so I've reached the point of walk away and leave it

[ozlad]

I do have a mostly there spare motor... if you need anything next time you come through just call

[Steptoe]

516

Has been and still is on the operating table,pulled down to the last en'th,

It got the better of me, I couldn't have it sitting there knowing it runs but not understanding why it won't.


The only obvious thing found is the hyvo chain is so loose it is chopping into the slap pad above it, so maybe it is trying to climb onto the next tooth causing a lockup , being caught between the crank teeth & the pad.

So while it's down we're throwing a set of mains & big ends at it, a decent bath to wash the old oil stains off it, put it back together with precision & care with a few wise thoughts from this here site & Bob should be your Uncle.
will keep a success or fail log going

[Steptoe]

we're back,,,,,,,sort of

WE HAVE AN UPDATE

over the last few months, I've pulled # 516 down,gone thru all parts and inspected,,

have needed to replace "hyvo" chain & pad, and a full set of bearings,,yep, pretty boring but needed to be done,,

washed every thing, have put it back together "fussy fussy" {obsessive compulsive type of thing }

initial start up went brilliantly,,, wound over{VERY EASILY} a little before firing and starting,

with out carby sync or adjusts of any sort, she idled almost straight away, at this point I'm thinking I've done it,, let her get hot listening for any noises,,, nothing,,, so I turned it off, feeling good.

went back into the cave to start final clean up, was in there a while,I thought we'll go back out & try again,,,, yep locked up just like before,,

am thinking I might pull the plugs to see if it will spin freely,and then am not sure where to go from there