Engine Stalls

[frankp]

Hope you guys can bail me out.  Here are symptoms:

Starts fine, but engine will die when gas applied.  Letting up immediately on throttle and the engine will resume normal idle.  After engine is warm, the hesitation is lessened, but engine will still quit.  To me, this describes a vacuum leak that partially seals as the engine temperature increases. It is possible to feather the throttle to get to high rpm.  At this stage, it doesn't stall with increased throttle.

With my high frequency hearing loss, I can't really hear much, but my wife said it sounds like "chirping."  (been told a functioning vacuum tank makes this sound)  Wasn't not stalling last year.  Have not taken off the carburetor this year.

All ideas appreciated.  Thanks, frank

[chetbrz]

Frank,

It sounds like it is starving for gas.  Of course a major vacuum leak will create the same issue.  Is the vacuum fuel pump filled with enough gas to keep the old girl running ?  Sitting for a time might have caused the gas to evaporate and it might need a little priming.  Is everything tight on the intake side, carb included ?

My 2 cents..  Chet...

[frankp]

Thanks, Chet.

That was my first impression, too.  Went for several mile drive.  Vac tank believed to be function correctly.  Will check all the bolts on carb and manifold this afternoon.

Manifold to engine and carb bolts all tight.

[frankp]

Cleaned the Accelerator pump adjusting screw and it is much better, but still has a noticeable hesitation.  Accelerate slowly and ok, push it, no.  Removed Air cleaner and sprayed a little carb cleaner - didn't notice difference.  May put Sea Foam in gas tank.

Chet, I think you're on the money.  May have to remove carb and blow out the jets with air.  Don't like taking apart because it's always a challenge to get used gaskets sealed.  New gasket set costs $50, maybe I'm too cheap to do this every year.  Might give a discount if order a gross.

When anyone has engine running issues I always suspect the carb first, based on my experience.  In all the 48 years, I've had 2 electrical problems, loose wire (operator error what's wrong with finger tight?) and a bad condenser.

[chetbrz]

Frank,

It sounds like you are on the right track also.  I started running all the gas out of my snow blower, generator, and power washer.  They are all 4 stroke engines.  It seems that the longer they sit the harder it is to get them going again.   Unlike the chain saw which is a two stroke engine.  That can sit around for years and start right up.  At least it did last summer.  Since I have been running them dry of gas when I am finished with them, they give me less trouble when I need them again.  Hopefully blowing out the jets will do the trick. 

Chet...

[imoore]

Sounds like you may have a blocked jet.
When i have an issue like this. That i suspect to be a jet issue. Try removing the air cleaner. Bring the engine to a fast idle  and cover the air intake with your palm for a split second. This will suck fuel from any and every jet or orifice. You may have to do this a couple of times. Keeping in mind it will flood the engine which is why you need a high rpm so it will clear with out stalling.
This might just save pulling carby apart for a clean up.
Ian

[frankp]

Chet,  I've thought about doing that in the past, but I don't have a hose to get the fumes out of my storage area.  Maybe I should spring for one.  However, won't there still be gas in the bowl and all of the jets immersed?

Thanks Ian,  I did that yesterday, but not with a very high rpm.  Easy enough to remove cleaner, so will do again today.  If doesn't work, we're expecting rain tomorrow, so it will be good day to remove bowl and clean.

[racertb]

Frank - I wish I could help!  I can't even get my old gal started still 

[frankp]

Racertb,  My problem is small compared to yours.  Wish I had some pearls of wisdom to give.

Put about 40 miles on yesterday to confirm the carb needs to be removed.  I just hope that will do it for me.

[Doug]

Here is my 2 cents. What kind of card are you using? If it has an accelerator pump, and stalls on acceleration, that pump isn't working. When you open the throttle you have to have a rich fuel mixture. Got to take the carb off and see whats wrong. If your using ethanol fuel it will eat up any cork gaskets floats seals, and those little crumbs will get in every little hole
 

[frankp]

Thanks Doug, makes sense.  Carter RT-08, probably a 130SA

2 steps backwards today.  After cleaning, accelerator pump cylinder now filling with gas; sucking in gas vs pushing air into pump jet.  Unable to remove all jets for this system.  Thought I found the problem when I freed the ball in the ball check assembly during cleaning.  Interesting note, all brass was covered in a green substance as if gas is leaching the copper from the brass.

[Old Man]

I understand that the 10% markings on some of our station gas pumps is behind the times. I've been told we already have 15% alcohol in our petrol here in Canada. I had to replace the rubber pump diaphragm in my 1930s AC pumps because the alcohol at 10% dried out and split the rubber. I recut new ones from a sheet of neoprene. The new neoprene I'm told can take the alcohol. But I'm wondering what new and wonderful problems we're going to have now. This green growth on brass has me wondering if this is the "15% problem". Alcohol absorbs water and mixes it through out the gas tank. So instead of a 'miss' every once in a while as a bit of water goes through the system,we are constantly having water run through the system. I wonder if some of these old cars will have to be modified in some ways to run decently. 

[frankp]

Old Man, as far as www says, we in Minnesota are still at 10% alcohol by volume.  Green color reminds me of polishing brass with Brasso.

Dave told me about Gunk Carb Parts Cleaner in a gallon can and had to have one.  My carb hasn't been this naked since 2008.  Unfortunately, the Low speed jet tube wouldn't budge, but really put the air to after it soaked for the afternoon.  Plan to reassemble Sat and expect the best.  Thanks to Chet for providing the idea to layout the parts for a pic.  (having a digital cam now helps immensely)

[frankp]

As Willie Nelson would say - On the Road Again.  Hesitation gone, now to reduce the idle.  Suspect the accelerator pump is set too high for the throttle position.  Spring won't return throttle but foot will.  Checked freedom of movement several times before installation, but ....

[Crazydave]

Thinking about the green gunk in your carb, do you happen to use STA-BIL or some other fuel conditioner? It has been my experience with seasonal vehicles snowmobiles in particular, that STA-BIL does that to the carbs. Friend of always used it and had trouble every fall, I use seafoam or nothing and never had a problem. He stopped using STA-BIL and runs them dry every spring, and is no longer cleaning the carbs every year.