Hard starting after long storage

When put my 1969-70 Commando "S" away 30 some years ago, it was a 1 or 2 kick starter. Last year, I got it running and on the road again. I did the typical stuff first, isolastics, tires, seals, etc. I squirted oil in the cylinders and liberally in rocker chamber, etc. before I first started it last year. I had stored the carbs dry, and they looked good enough inside, so I didn't spent time cleaning them. But now its 30 to 40 or more kicks to start. You might as well forget even trying if its under 50F in the garage. I have never used any gas with ethanol due to still having a fiberglass tank. Stock Amal Carbs. Stock points, which I did polish.

I have not taken off the head or cylinders yet, but compression reads about 145 psi on one side, 146 on the other (cold, with 8.9:1 stock Norton pistons, 0.020 over.) I do not remember what normal compression is, but I am thinking maybe a little higher. Oil burn was not really noticeable, but I only rode it about 200-300 miles this year since it was such a PAIN IN THE ASS to start and due to difficulty getting the non-ethanol gas. Its not getting any better. Spark seems pretty good (it will jump 1/2" easily). Runs fine once started, but does seem to take longer to warm up before it will keep running at idle. I had to turn up the idle speed just a tad. After maybe 100 miles of this starting torture, I put in new Viton needles and upgraded floats, which made absolutely no difference.

I can't seem to flood the engine by too much tickler depression. It seems to me that it used to readily flood with too much tickling, but then 30 years is a long time to remember. Fuel will spill out, but I can hold the ticklers down over 10 seconds after they start spilling gas and it still will not start and no wet plugs even with full choke. Is there some fine passage that allows high float level to feed to the intake that might have scaled or corroded closed while stored even though the carbs were stored dry and looked spotless inside? (It doesn't seem it would be a regular idle passage, since the engine runs fine once its warm.) Or maybe does 100LL cause hard starting?

Thanks

Ted Lang said:

Or maybe does 100LL cause hard starting?

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100LL contains a considerable quantity of lead (despite the name) that can easily foul plugs.
Tried new plugs in it for this year ?

If the carbs dried out with fuel in them, then debris and corrosion can block things up,
and could well be worth a good clean of the carb, including the idle fuel and air passages.

Anything more than 2 or 3 kicks is a pretty fair sign that something isn't quite right in the tuning dept.
Better to chase it now, rather than wear out the kickstart mechanism - or someones knee....

Many factors here. Clogged pilot jet passages always No.1 as far as carbs go. Electrical check lousy British old connectors ,corroded ground(s) , weak battery and on and on. Spark plugs new ?

I'd certainly clear out the pilot jets, if it sat that long unused.
Remove the mixture screw. See if you can push a small wire (no bigger than 0.016" diameter) at least 1.5" into the carb body. If you can't, the pilot jet is blocked. You can clear it with a 0.016" wire, number 78 drill or 0.4 mm drill. If you use drill bits, you'll need to extend them with a piece of small tube like the nozzle from a WD40 spray can.

At a pinch, I've used the wire inside plastic bag ties after melting the plastic off them. They measure 0.014" diameter. When the jet is cleared, remove the float bowl drain plug and squirt WD40 or carb cleaner into the mixture screw hole. That will blow any rubbish out at the drain plug.

Another useful thing I've found for long-stored engines ( a year or more without use) is to remove the exhaust pipes from the head and start the engine. Run it for about 30 seconds, giving it blasts of throttle. Give it a good handful, and completely close the throttle before the revs get too high. Just do that on/off, on/off and make a lot of noise.
When the engine cools down, check and set the valve clearances.
You'll normally get a compression increase in the process, which you may not get even after months of normal use. It just cleans any crud off the valve seats.

Are you storing the bike with fuel in the tank ? If so, there could be couple issues. 1) the fuel is leaching the resin out of the fiberglass and gumming up the carbs 2) the fuel is simply stale. Today's fuel is a mix of who knows what, it eats fiberglass, and is not very stable. It is not the gasoline of 1970. You could always drain your existing fuel and try a gallon of fresh pump gas (87 octane is the most volatile) and see what happens.

Greg

I would remove the tank and all feeds to the carbs including inspection of taps... check that all parts are freeflowing... Maybe you have a "cellar dweller" that has made a home in the pipework..

You're on the right track, good work. Quick acid test, pull the plugs, teaspoon of gas in each hole, thread them in, kick it up. If it fires, pull the carbs, remove the welsh plug sealing the idle circuit chamber. Clean/verify passages.
If no joy with gas in the cyl, look at the kill switch ( hot wire bypassing main ignition switch and kill switch)
Report back please

I suspect you're going to find the idle passages are the problem but the other thing is that avgas, as someone else has already pointed out, is made to be less volatile so that it doesn't cause a vapor lock condition at altitude. It may take more tickle to get enough gas to turn to vapor to get it to start.

I've run my bikes on 100LL when I couldn't get ethanol-free pump gas and they started just like normal - hold the ticklers down just until the fuel starts running out. Suspect the OP's problem is a combination of stale gas and clogged idle circuits. Modern gas goes stale in a couple of months. Also if the sump is full of oil they are harder to start.

If you're still on points, the contacts may have a 30 yr. film on them or even a bit of rust. And check that the auto advance is not stuck.

"...remove the exhaust pipes from the head and start the engine. Run it for about 30 seconds, giving it blasts of throttle. Give it a good handful, and completely close the throttle before the revs get too high. Just do that on/off, on/off and make a lot of noise."

I would be very leery to do this, as it can quickly lead to warped exhaust valves. 'Not to be a nay-sayer, but why take the chance if you already have 145psi compression?
As noted numerous times, go for the idle jets. That's what went bad on my 25 year warehouse special.

Nathan

100LL is NOT the problem, stores well, runs well.

Nater_Potater said:

"...remove the exhaust pipes from the head and start the engine. Run it for about 30 seconds, giving it blasts of throttle. Give it a good handful, and completely close the throttle before the revs get too high. Just do that on/off, on/off and make a lot of noise."

I would be very leery to do this, as it can quickly lead to warped exhaust valves. 'Not to be a nay-sayer, but why take the chance if you already have 145psi compression?
As noted numerous times, go for the idle jets. That's what went bad on my 25 year warehouse special.

Nathan

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I've done it too many times, and sometimes seen 30 psi improvement in compression. It's never caused a loss of compression.
I've even done it where valves were damaged from running insufficient valve clearance. The damage was restored, and compression came back.

X-file said:

Nater_Potater said:

"...remove the exhaust pipes from the head and start the engine. Run it for about 30 seconds, giving it blasts of throttle. Give it a good handful, and completely close the throttle before the revs get too high. Just do that on/off, on/off and make a lot of noise."

I would be very leery to do this, as it can quickly lead to warped exhaust valves. 'Not to be a nay-sayer, but why take the chance if you already have 145psi compression?
As noted numerous times, go for the idle jets. That's what went bad on my 25 year warehouse special.

Nathan

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I've done it too many times, and sometimes seen 30 psi improvement in compression. It's never caused a loss of compression.
I've even done it where valves were damaged from running insufficient valve clearance. The damage was restored, and compression came back.

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If its working for you, great. I wouldnt do that to any engine of mine or advise anyone else to do it.
Sounds like a way to cause more damage.
Good luck with that.

concours said:

100LL is NOT the problem, stores well, runs well.

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Agreed on that. I've used thousands of gallons albeit in airplanes, not motorcycles. Something I observed in airplane with an STC to burn mogas was they required fewer pumps of primer when cold that when running on avgas. Auto engines ran just fine, even with 115/145 except for the beautiful coat of brown in the tailpipe.

When I stored it many years ago, it was completely drained, both carbs and tank. No ethanol gas ever (unless I got it somehow 30 years ago) Also put oil in the cylinders, rolled engine occasionally, and stored on an inside wall of an attached garage. Now it has new fuel lines (originals were actually brittle) with good flow TO the Amals, fresh fuel in the tank, and starts really hard.

If an idle passage is plugged,would it still idle ok? But like I said, it does take a long warm-up to idle smoothly and I can't seem to be able to over tickle it. I like the suggestion to pour a teaspoon of fuel in each spark plug hole, re-install and kick. I will try that this weekend.

I take it that my compression is in a normal range? Engine has 19,900 miles total, but the first 5000 miles with the PO were hard. I got it in 1974 after mains and oil pump were replaced. But the PO didn't clean the oil tank or replace pistons. I remember sticking a magnet in the oil tank and pulling out a 6" snake of metal chips. At that time I had it re-bored for Norton replacement standard 0.020 pistons, and added a real oil filter. These pistons have served for about 15,000 easy miles and it has not been apart since.

By the way, the PO had installed an alloy rim on the rear only. Since I got it, the bike had always pulled to the side and I thought maybe the frame was bent or something. I put up with that for years and just got used to it. When I was going through it last year, I saw some posts on this forum about rear wheel offset, and as you might guess the rim was exactly centered on the hub. I relaced myself with SS spokes and corrected offset (also did swingarm mod) and viola!! it tracks straight. ...... just wish it would start!!

MikeM said:

X-file said:

I've done it too many times, and sometimes seen 30 psi improvement in compression. It's never caused a loss of compression.
I've even done it where valves were damaged from running insufficient valve clearance. The damage was restored, and compression came back.

Click to expand...

If its working for you, great. I wouldn't do that to any engine of mine or advise anyone else to do it.
Sounds like a way to cause more damage.
Good luck with that.

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When reality doesn't agree with theory, what do we do?
Try to change reality, or get a better theory?
It has always caused an improvement. I've only been doing this successfully for about 45 years, so maybe I speak prematurely, and there is some risk.

There is a big difference between a red-hot exhaust valve on an engine running at full throttle and full power, and an engine being run for 30 seconds from cold in neutral with no net power output. Heat absorbed (and later dissipated ) by the head and exhaust valve is roughly proportional to the square root of fuel consumption. Fuel consumption of an engine running in neutral is minimal.

Maybe some of the theories about potential valve damage should take that into account, because they currently don't agree with reality.

Glanced over as if concerned someday to notice - spark able to jump 1/2" which is wonderful but not being tested through the plugs which may spark outside w/o compression but not under pressure so maybe for luck and check off more eliminations try new plugs. If already have never mind likely never run right again. One 850 stored at my place a few year was a booger to start and then would not respond to pilot screws after clearing so messed with float till 1.5 turns out idled good and it was happy kicker after. Its also possible somethings shorting when plug leads installed so kick in the dark for hints of flashes to trace. Btw the whitish crust fround stained with what ever is what coaches put on noses, zinc oxide leached out of the 'pot' metal. Mild acid like acetic or bath and bowel lime cleaner will get it pretty quick w/o bothering the base metal. Should only have to kick a few times before giving up and doing something different or same old thing over just in case, otherwise you may have a kick lever slpine and ratchet wear issue too not to mention the cam/lifter galling. In some of my desparations I'd fudge timing an Nth degree at a time, finger tighten stable then kick once or twice, then next Nth degree ditto'd till obviously the wrong way then creep back up till joy,- if timing is an issue. Air leaks all accounted for of course. Lick this and rest of life is a breeze to over come.

Do you know anyone with a good starting Commando who would loan you their carbs so you can sort out whether it is a fuel or ignition problem?

Greg

Snake of metal chips ,replaced mains and oil pump tells us this baby needs way more than a start up. More like a tear apart and start again. :|