FAQ
TL;DR: 1:32 mix can run but smoke; "after such attempts it is 100% flooded." Clear floods and skip choke on warm restarts. [Elektroda, płetwa, #17199573]
Quick Facts
- At 40:1, use 125 ml two‑stroke oil per 5 L petrol; 160 ml equals ~31.25:1. [Elektroda, wojtek1234321, post #17199615]
- Avoid re‑priming and re‑choking after a 20‑minute pause; it floods the cylinder. Clear by removing the plug and pulling upside down. [Elektroda, płetwa, #17199573]
- Quick diagnostic: inject a small dose of fuel via the plug hole with a syringe; a brief run confirms fuel starvation. [Elektroda, Pedros050, post #17199586]
- "Rich mix" smokes more; a bone‑dry plug after pulls suggests no fuel delivery. [Elektroda, Pedros050, post #17199553]
- If the air filter is dry/clean yet it still won’t start, suspect the ignition coil and replace it. [Elektroda, KrisPan, post #20148828]
How do I fix a STIGA SBC 252 D that wont start when hot?
Do not choke or pump the primer again on a warm engine. Over‑priming floods the cylinder. "The scythe after such attempts is 100% flooded." Clear the flood by removing the plug, inverting the unit, and pulling several times to expel fuel. Refit the plug and pull to start with the lever on Run. If it still fails, let it sit a minute, then try again without choke. [Elektroda, p2etwa, #17199573]
Whats the correct fueloil ratio and volumes for 5 liters?
For 40:1, mix 125 ml of two‑stroke oil with 5 liters of petrol. Using 160 ml in 5 liters is ~31.25:1. This richer mix will not match 40:1. Keep ratios precise to avoid smoke and plug fouling. [Elektroda, wojtek1234321, post #17199615]
Could a ~31:1 mixture seize my new engine?
No. A richer mix (more oil) reduces seizure risk. It may smoke more and foul the plug. "Rather, there is no fear. It can only smoke more." Use the manufacturer’s recommended ratio once the engine is running correctly. [Elektroda, wojtek1234321, post #17199650]
Should I choke and pump the primer after a 2020 minute break?
No. Avoid re‑choking and re‑priming after a short stop. That floods the cylinder and prevents ignition. Clear the flood if it happens, then restart without choke. This behavior is typical when a warm two‑stroke is over‑primed. [Elektroda, p2etwa, #17199573]
How do I clear a flooded twostroke brushcutter?
Use this 3‑step reset:
- Remove the spark plug.
- Turn the unit upside down and pull the starter several times to expel fuel.
- Reinstall the plug and start with no choke.
It should fire after this procedure. [Elektroda, p2etwa, #17199573]
My spark plug looks dry after many pullswhat does that mean?
A bone‑dry plug indicates fuel is not reaching the cylinder. One expert noted the plug was "dry as pepper" despite a rich mixture. Suspect fuel delivery issues rather than ignition. Check primer action, fuel lines, and tank filter next. [Elektroda, Pedros050, post #17199553]
How can I quickly confirm a fuel delivery problem?
Do a syringe test. Inject a small amount of fuel through the plug hole, refit the plug, and pull to start. If it fires briefly and dies, you confirmed fuel starvation in the normal path. Proceed to inspect the fuel system. [Elektroda, Pedros050, post #17199586]
I see spark; should I still try another spark plug?
Yes. Swap in a known‑good plug to rule out a weak or failing plug under compression. As one helper asked, "Do you have replacement candles?" It’s a quick, low‑cost check before deeper diagnostics. [Elektroda, Pedros050, post #17199474]
When should I suspect the ignition coil on this trimmer?
If the air filter is dry and clean, yet starting fails despite fuel and plug checks, suspect the ignition coil. Replace the coil as the next step. Coil faults often present as intermittent or weak spark and hard restarts. [Elektroda, KrisPan, post #20148828]
Does a rich mixture cause smoking and harder starts?
Yes. A richer mix will "work and smoke more." Excess oil can wet or foul the plug, making restarts harder. Ensure the correct ratio and clear any flooding before retrying. Return to the recommended mix once it runs steadily. [Elektroda, p2etwa, #17199573]
so with the hard work of a new, unbroken machine, anything can be done with such a mixture.
