Why does starter fluid cure my no start? What is the issue?

[fried1765]

Re: Why does starter fluid cure my no start?

One month ago I'd have had trouble starting a mower full of Summer blend gas in those temps.

When did you top up the tank last? You'll want Winter gas to push snow.

If you are willing to pay the extra cost, 100LL aviation gas works fine all year long.

 

[TimberHole]

Re: Why does starter fluid cure my no start?

If you are willing to pay the extra cost, 100LL aviation gas works fine all year long.

And it never spoils. I’ve seen planes fly on 100LL that was 5 years old. No problem.

 

[fried1765]

Re: Why does starter fluid cure my no start?

And it never spoils. I’ve seen planes fly on 100LL that was 5 years old. No problem.

THAT is the reason that I use it for my small engines.
It is worth the cost to me!
I often store my small engines for long periods, and 100LL stores almost forever!

 

[ray66v]

Boat gas is ethanol free, stores for long periods, and is usually like 90 octane.

It's perfect for small engines, (especially 2 cycle), better for the environment, and much cheaper than 100LL.

That being said, it's obviously not available in all areas. Which is a shame.

 

[paulfun9]

Stalls normally don't. If you hit a stump or anything to cause the blade (crankshaft) to stop suddenly, the flywheel will try to continue spinning. That's what sheers the key. In a backfire, the crankshaft is forced to turn backwards while the flywheel is still trying to move forward. The key shears to save the crankshaft. That's why the key is made from very soft metal. The key is also the ignition timing index.

The shearing may or may not be complete. I've seen keys sheared only about half way through and still allow the engine to run. They'll be hard to start and won't run with full power but they will run. That's because the ignition timing is retarded. If you take that half-sheared key and turn it around to advance the timing, you'll gain about 10-15% more power. It may be hard to start there too but it will run like you've never seen before. The factory timing is a compromise to allow easy starts. That is in addition to cam lobe timing. But I don't even want to get into a cam discussion here.

I used to race Karts. I ran in the Super Stock class running on pure Methanol. I built and tuned my own engines. What started as a stock 5hp Briggs & Stratton was putting out about 10hp on race day. When your rear is in a seat about 1" off the ground, 80mph feels like 280. That is a rush! That was at the Mid-Ohio track. The usual Kart tracks will only allow about 30-40mph in the straights before the first hairpin.

Sorry to drift. Those were the days.

All I'm trying to say is if you need starting fluid, something is wrong. The engines were not designed to be started on ether. (Some are but not small utility engines.) The problem can be fuel, air, ignition or any combination of them. Also, valve clearance can effect starting. This is part of a fuel/air combination. You would be surprised at just how complicated the engineering of these small engines can be. It's not just gas and oil that keeps them running.

No matter your experiance or confusion on my experiance, thinking I need explination on where and what the parts are or what they do. I will make my statement again, If the key shears while trying to start with starting fluid then it will also shear on backfires from gasoline as well. This makes the recommended non use of starting fluid null and void as I feel most are more likely to have backfires and flooding type conditions if they keep trying to start with gasoline then a simple quick spray of starting fluid. Which by the way can most times be done without removing any parts. Whit mine the choke has been non functioning for years and all it takes for a quick, easy backfire free start is a quick shot of starting fluid on one corner of the filter.
Most issues people with hard starting mowers will face is worn-incorrect plug or plugs, improperly or non functioning choke and worn-low compression engine. For the hassle involved and the cost of fixing the choke I would estimate my can of starting fluid will outlive the mower it was purchased for and make the repair not needed ever.

 

[paulfun9]

A few thoughts on small engines that tie in with this thread: 1)Repeated starting fluid use can actually be habit forming for engines. It is better to address the issues rather than rely on its use. Carburetor spray is a safer alternative and for intermittent use. 2) Your carburetor's throttle plate is wide open. Right now, no matter where the throttle is set- it is wide open when the engine is not running. If you can see the throttle arm or linkage, watch it try to close as you crank the engine and as the engine starts.3) Briggs Intek twins can normally require extended cranking when cold if they have sat for several weeks. Mostly it is simply the design of the intake manifold and the performance of the carburetor. For best results, stabilize your fuel and run every couple of weeks to cycle fresh fuel into the carb plus maintain the fuel level in the float bowl. If they (or really just about any OPE engine) have a cold starting issue every time- ensure the choke is closing, the fuel fresh, test for fuel pump output at first crank, feel for the click of the anti backfire solenoid at the bowl of the carb when the key is cycled. These four things seem to be the issue with the majority of cold start issues. Of course there are other factors which may require attention. 4) Many of the smaller engines that had primers were more forgiving than a like engine with a choke for cold starts. Many went to auto chokes, including the twins on your rider. A step forward?

Someone forgot to tell my mower it痴 throttle plate should go wide open when I turn it off at idle speed. Mine only goes wide open when I put the throttle wide open.

 

[Sittingbull2]

What kind of motor is on your mower? Does it have a electrical solenoid on bowel of carburetor? That is a solenoid for making gas flow or shut off when you turn key off/on

 

[paulfun9]

A few thoughts on small engines that tie in with this thread: 1)Repeated starting fluid use can actually be habit forming for engines. It is better to address the issues rather than rely on its use. Carburetor spray is a safer alternative and for intermittent use. 2) Your carburetor's throttle plate is wide open. Right now, no matter where the throttle is set- it is wide open when the engine is not running. If you can see the throttle arm or linkage, watch it try to close as you crank the engine and as the engine starts.3) Briggs Intek twins can normally require extended cranking when cold if they have sat for several weeks. Mostly it is simply the design of the intake manifold and the performance of the carburetor. For best results, stabilize your fuel and run every couple of weeks to cycle fresh fuel into the carb plus maintain the fuel level in the float bowl. If they (or really just about any OPE engine) have a cold starting issue every time- ensure the choke is closing, the fuel fresh, test for fuel pump output at first crank, feel for the click of the anti backfire solenoid at the bowl of the carb when the key is cycled. These four things seem to be the issue with the majority of cold start issues. Of course there are other factors which may require attention. 4) Many of the smaller engines that had primers were more forgiving than a like engine with a choke for cold starts. Many went to auto chokes, including the twins on your rider. A step forward?

Can you recommend a good therapist for my mower? I am starting to think this habit of ingesting starting fluid has become an addiction!

 

[ForumJunkie]

It was a broken choke shaft.

Problem has now been fixed.

Thanks for all the feedback!

 

[tomplum]

Good deal. Thanks for the report!