Sticky needle valves

[rob love]

Just thought I would check to see if others have been having more pronounced problems lately with the carb needle valves sticking. I went to get three vehicles going for an event the other day, and 3 out of 3 had this symptom. With fuel or ether down the carb, the engine would run until it burned that off, but would not maintain. Once I would crack the fuel line at the carb so fuel would reach the carb, then gave the carb a few whacks, everything performed as it should. But even then, a week later, the artillery tractor gets onto the trailer, heads to the display, and then has the stuck needle again. The carrier initially gave me the same problem, but now it's the other way with what would seem to be a wide open valve after sitting for just half a day.

The chev artillery tractor just had its carb rebuilt about 6 months back, the two Fords (carrier and Lynx) have not had rebuild kits into them for at least 4 years that I know of (likely a lot longer on the carrier, although we did dis-assemble the carb last year and re-assemble it after cleaning). Fuel pumps on almost all these vehicles are newer as there have been total failures of them with being parked seasonally, and I suspect incompatibility with the ethanol.

We have the 10% ethanol blend here in Manitoba. A quick google search has many, many hits with the same problem, particularly on outboard motors.

I am going to try a few different fixes as an experiment. I am going to drain the fuel from the tractor, and replace it with a higher octane non-ethanol fuel and see what the results of that are. I may also try some stabilizing additives and see if they help.

Another I will try is replacing the rubber tipped needles with solid brass needles, like the old days. For the brass needles, your fuel must be really clean, and to that end I normally have a larger fuel filter unit before the pump, and a smaller one right at the carb. Rust and debris should not be an issue.

Today’s fuel reportedly has a very short shelf life which is far exceeded by winter here in Manitoba. Several of our vehicles are due to go onto military change of command parades in the next few months, and I would like the operation of these vehicles to be seamless.

So what is the experience of the MLU collective, and what solutions have worked for you guys?

[chris vickery]

Rob, the ethanol type gasoline is a major source of trouble for many reasons.
Lucky here in Ontario there are a couple places where the gasoline is ethanol free (Esso Premium and Shell V-Power)
When I bought a couple new pieces of lawn and garden equipment last year, both places told me under no circumstances to use ethanol blended fuels and to only run premium.
As you pointed out, needle valves with rubber tips- bad.
Ethanol is a solvent which destroys any and all rubber components. add to the fact that many of our small engines today are also made off shore from material of dubious quality and it furthers the problem. Old type rebuild kits are also trouble whereas modern kits for the most part have upgraded the materials to include diaphragms, gaskets etc which will stand up to ethanol.
There is also the other side of the coin; what many people do not understand is that ethanol is a CHEAP additive for gasoline. Petroleum companies have been adding it as a way of "cutting" the product to the consumer, for lack of better terms, watering it down...
The burn rate of ethanol is much quicker than gas as well, in essence, you burn way more quantity and get less MPG. I calculated it out comparing Regular to Premium on a cost per Kilometer and as it turns out, Premium is actually the better value. I know that my truck gets way more miles out of a tank of Premium than it does Regular.
Anyhow, back to your question. This has been discussed at length on the G503 Forum, specifically on the M274 Mule section. The common theme is that whenever guys mules quit running for some mysterious reason, it always comes down to a new fuel pump and carb. Co-incidence???
I run all my MVs now on Premium and will likely run my mule on 100LL Avgas once its finished. Problem solved.

[Wayne Hingley]

I have no other solutions, but will reinforce what you both have stated about people using non-ethanol premium fuel in MV's that sit, or where there are components that do not have a tolerance for the ethanol content.

I try to use fuel stabilizer in all of my seasonal or low-use fuel tanks. It is amazing how quickly the fuel goes bad these days.

Im interested to see what other ideas/solutions come up.

[Phil Waterman]

Hi Rob

From your problem statement that you are having two problems with the float valve. One that they are sticking open other that they are sticking closed.

Agree the ethanol is probable cause.

Now to the diagnostic questions:

Do any of these vehicles have electric fuel pumps?

Are the vehicles in cold or heated storage?

Are you pulling the choke all the way out?

Even though the engines turn over have you tried hitching up a jump or charger?

Now to some observations on starting my three CHEVY CMPs. They all have different starting personalities even when sitting side by side in the shop for a couple of months.

All my trucks have either primary or secondary electric fuel pumps. All of these are on switches so that they can be turned on or off. When starting one of the trucks that has been sitting for a while I turn electric pump and you can hear a difference in the click of the pump as it fills the carb float bowel.

Concerning the choke, two of the trucks want full choke to start in the cold you can hear the "waa" sound of the choke. The HUP requires full choke then half inch in, it will flood and not start if cranked with the choke full out.

On the trucks with no mechanical pump if the engine floods then turning off the fuel pump and holding the throttle wide open and cranking clears its and then starts. On the one which retains it's mechanical once flooded only sitting will clear the flooded conditions.

I have removed all the viton tipped needle valves and replaced they with the old style all steel needle valve. Also have replaced all the pre-ethanol rated rubber parts fuel lines, pump diaphrams etc.

Now as I said in my New Years Day post all of this is not a guarentee that the trucks will start on demand. The all three trucks had been standing for four months the two in cold storage started the one in heated shop didn't.

One last extended parked start problem issue. The stale fuel needs a hot spark to fire and if the engine has to crank for an extended period to prime the carb. The spark may just not be hot enough to fire the fuel, simple trick is to put a battery charger on the battery the day before you want to fire the engine after a long sit. Even an hour before the you hit the starter will top up the battery.

Cheers Phil

PS Thanks for posing the question and thanks to all who respond, will make good Tech Tip topic for newsletter.

[rob love]

Well I had at the carrier today to start things off. I pulled the top off the carb, and checked the float. There is a little rattling in it, but it does not have fuel in it. I put a new needle in, set the float a little lower, and it is running great now. I'll get a kit for the carb a little later in the season, but for now it's OK. That one normally does not need any choke, but of course it's a Ford, so that is to be expected.

Went to start the White scout car, and over 3 weeks it developed the same problem again: stuck needle. I cracked the line before the carb, gave it a couple taps with the wrench, a one second shot of ether, and away she went. The fuel is getting pretty stale in that one, so I'll be draining the tank this season and she'll be over to a mix of premium and avgas I think.

The Chev Artillery Tractor started OK today and I have her back in her spot. The top will be coming off that carb and the rubber tipped needle is giong to join file 13 (the dumpster). That one is on standby for towing a funeral carriage, as well as going to be on the Change of Command in a couple months. The carb kit I bought for it 6 months back was supposed to be OK with ethanol....I'm not so sure now.

The only vehicle of the bunch that has a secondary electric fuel pump is the lynx, and aside from it's first start of the season, it has been working well. I have never done the carb on that one, so perhaps it is overdue. On it's first start, I ran the electric pump for quite a bit, and it did not want to go. Cracked the line, tapped the carb, and away it went. But once again, it's a Ford, and I would expect nothing less.

Did get a pleasant surprise this afternoon with the C15TA. That one is notorious for not starting, and a tune up and carb job are long overdue on her. She did not want to start, so I reached uunder the panel and tickled the wires near the ignition switch.....away she went. Methinks I may have some wiring to do this season. There were way too many of those quick crimp blue connectors put on some of these vehicles in the past, and combined with the fraying 70 year old cloth wiring, are not a good combination.

Anyway, coffee break is over and I have to go put double and triple drain pans under all the Chevs now.

[chris vickery]

Rob, do you use Oilwik absorbant sheets under all those Chevs? I can put you onto them as we use a ton at work for oil management. They keep a garage floor tidy.
If not familiar, here is the website:
www.pigmalion.ca

[chris vickery]

One of the main issue with ethanol is that it is hygroscopic in nature, which means it has a propensity to attract and hold water. This is the reason that it is useful as a fuel line anti-freeze. Water in the fuel is one issue as water attacks and corrodes the fuel system from the inside out- gas lines, fuel tanks etc. All of thee fine rust particles clog up the system, filters, carbs, pumps etc.
The ethanol as mentioned earlier is also a solvent when in contact with rubber components, plastics etc. Once again, turning these into goo which wreaks havoc on the fuel system.
A friend of mine had a small engine shop that he recently sold when he retired. He always told me that the best thing ever to happen for him was when the Petroleum companies started adding ethanol to the fuel.
His staff was always super busy, especially in the spring time when all the lawn and garden equipment came out of storage and then would not start. He kept plenty of kits, carbs and fuel pumps on hand to deal with the problem.
It seems that this industry has been slow to adapt, or outright refuses to upgrade their products to comply with modern fuels. Why would they?
The auto industry has adapted and overcome by introducing modern materials which are resilient to ethanol and other additives. Many cars are actually designed now to run on blends. South American manufacturers are building cars to run on as much as 85% ethanol, derived from corn.
I think in the long term, it is a case of using the best product available at the pump if it can be found. Otherwise, I would suggest that in the future, rebuilds on HMVs will require the ue of modern components in the overhaul of the vehicle. A 30 year old rebuild kit for your carb is still a 30 year old kit, made of rubber. Only modern materials made to handle ethanol will work long term.

[Phil Waterman]

Hi Guys

Well this morning being April 1 figured it would be good day to start all three trucks last time they were started January 1st. Last time the trucks were fueled was last week in July so the fuel is pretty stale.

All three trucks fired and ran fine, little weak acceleration on hills, did a GoPro video, but the only the only things of importance to this discussion is the sound of the electric fuel pumps priming the carbs. No starting ether no pumping the peddle just prime carb with fuel pump, choke and hit the starter.

Did remember one thing though from last time had starting problem, plugged modern fuel between tank and pump, the clear type should be able to see dirt and crud, but last time the filter looked OK but would not pass fuel. Back clear it with air and the pump worked and would then plug again. Cut the filter open and the filter the filter media was gummed with white deposit.

Sorry short on solutions long on observations. Only possible solution I see is drive more often.

Cheers Phil

PS Long no driving period was because of hand surgery.

[chris vickery]

Phil, are they adding ethanol to your fuels in the USA? Stale gas usually works, not the greatest depending on age but there may be a difference between US fuel and Canadian fuels...
I am going to hit the guy up down the road that runs float planes. I see he has a 500 gallon tank of Avgas sitting by the hangar.

[Phil Waterman]

Hi Chris

They started adding ethanol here in New Hampshire in 2006, immediately started causing problems. I first notice it the first time, filled some Canadian style Jeery cans that had always been carried on their sides in the side rack on my HUP, they had always been carried full and never leaked. Used them up at a rally, refilled them drove back to the rally and both caps were leaking. Opened them up and the gaskets in the cam lock covers were the consistency of marshmallow whip.

With in a very short time club rides and parades were being regularly interuptured with, leaky fuel lines, failed fuel pumps, plugged fuel filter. Took almost a year to get most everyone in the club to get the message. One on going problem was fuel pumps because so many pumps were and so much fuel line in the parts system. Think I replaced four mechaical fuel pumps in two years, until ethanol resistant Chevy fuel pumps started coming out.

Cheers Phil

[Stew Robertson]

Just an old trick from way back when that has served me well
add some mothballs to your fuel tank and they seem to help get rid of the water and dissolve the fine dirt
any carbs That I have used it on are always nice and clean

[Lynn Eades]

Stew, our moths are only small and it's just not worth my time to catch them.