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rteeqp73

Safety first (read before starting)
- Work in a well‑ventilated area. Keep flames/sparks away from fuel. No smoking.
- Use safety glasses, gloves, hearing protection if cranking engine. Beware hot parts and spinning belts/flywheels.
- Chock wheels, put tractor in neutral or park with brakes on. If you must run the engine, keep bystanders clear and remove loose clothing/jewelry.
- If lifting tractor, use proper stands; don’t rely on a jack alone.
- Disconnect battery negative before doing electrical work. When cranking for tests, reconnect only as needed and keep hands/metal away from moving parts.

Tools and consumables (minimum)
- Basic hand tools: metric/imperial spanners, sockets, screwdrivers, pliers, adjustable wrench.
- Feeler gauges.
- Spark plug socket & gap tool (for petrol engines).
- Compression tester (suitable adapter for TE‑20 spark plugs or injector blanking nut).
- Multimeter (DC volts, continuity).
- Spark tester/remote spark gap tool (for petrol engines).
- Timing light capable of 6V systems OR static timing/marked flywheel method.
- Diesel injector tester or method to observe injector spray (suitable wrench, rag, container).
- Fuel line wrenches, spare fuel filters, clear hose for bleeding.
- Torque wrench (for reassembly).
- Gasket set, spark plugs, points & condenser (petrol), coil (if suspect), diesel injector nozzles or seals (if suspect), head gasket set (if low compression).
- Shop rag, drain pan, small mirror/flashlight, inspection camera optional.

Notes on TE‑20 variants
- TEA/TED/TEF variants: TEA = petrol, TED = diesel, TEF = later diesel. Diagnostic steps mostly same in order but ignition tests apply only to petrol; injector/fuel pump inspection applies to diesel. TE series typically uses 6V electrical systems — be careful with test gear built for 12V.

Step‑by‑step diagnostic procedure

1) Visual & basic service checks (5–15 min)
- Inspect fuel tank for debris, water; drain a sample. Replace fuel filter and clean bowl if present.
- Check oil level and condition. Smells of fuel = possible worn rings/valve guides or overfuelling.
- Check coolant level and leaks.
- Inspect air filter and intake for blockage.
- Inspect fuel lines, clamps, tanks for leaks/soft spots.
- Look for frayed wiring, loose connections, corroded battery terminals, cracked insulation.
- Check belts and fan for damage.

Why: Most running problems are fuel, air, or electrical basics.

2) Battery & charging system (10–20 min)
Tools: multimeter, battery load tester.
- With battery disconnected and removed, clean terminals. Check battery voltage: healthy 6V battery ~6.2–6.4V fully charged (open circuit). Under crank voltage will drop; if below ~4V on crank, battery likely weak.
- Load test or try jump‑start. If charging suspected, run engine and measure voltage across battery terminals; generator/regulator should deliver slightly above nominal battery voltage (consult manual for exact values).
Common pitfall: Using a 12V charger on a 6V battery — that will destroy it.

3) Air & fuel flow checks (10–30 min)
- Air: Remove air filter and check for free airflow.
- Fuel: Check that fuel is reaching the pump/carburetor/injector pump. Open the fuel drain/test port; inspect for clean fuel without water. Put clear hose on a supply line and crank to see flow (diesel).
- Bleed system: On diesel, ensure lift pump and lines are bled. For petrol, ensure carb float is not stuck and tap float bowl to see fuel flow.

How to use the clear hose: Attach hose to outlet, crank engine, observe steady fuel flow (diesel) or priming for petrol. No flow = blocked filter, collapsed hose, or faulty pump.

Replacement parts: fuel filter(s), fuel hoses, pump seals. Common pitfall: reassembling with dirt in lines — always clean first.

4) Compression test (15–30 min)
Tools: compression tester, socket set.
- Warm engine a little (not required but gives realistic reading). Remove spark plug (petrol) or blank off injector and insert compression tester adapter (diesel: remove injector pipe nut and use adapter or use a compression gauge on injector hole if available).
- Disable ignition (remove coil wire or ignition lead on petrol; disable fuel for diesel).
- Crank engine with throttle open for 4–6 compression strokes; record pressure per cylinder.
- Compare readings: all cylinders should be within ~10–15% of each other. Absolute numbers: consult the TE‑20 service manual for exact values; low compression suggests worn rings, valves, or head gasket leak.

How to use tester: Screw into spark plug hole hand tight, lead hose to gauge, crank engine and record peak pressure. For diesel, expect higher compression than petrol.

Common pitfalls: Not disabling ignition leading to sparks in tester; misreading a cold test compared to hot; relying on one cylinder only.

5) Ignition system — petrol engines only (15–40 min)
Tools: spark tester, multimeter, gap tool, feeler gauges.
- Spark plugs: Remove, inspect for fouling, gap and condition. Replace if fouled, cracked or electrode worn. Typical service interval replacement is common.
- Coil and HT leads: Check resistance of coil primary/secondary to known values (consult manual). Use spark tester: connect between plug lead and spark plug, crank engine, look for consistent bright spark.
- Points & condenser: Inspect points for pitting, set gap with feeler gauge to spec (if no spec available, typical points gap ~0.014–0.018 in — check manual). Clean cam lobe contact, or replace points & condenser if worn.
- Timing: On 6V systems, a timing light may not work unless rated for 6V or powered by a separate 12V supply — alternatively use static timing (turn engine to TDC with piston 1, align marks on flywheel and set contact breaker to the manual’s angle). If using timing light, connect to coil negative and ensure correct supply voltage.

How to use spark tester: Attach tester inline between coil/distributor and plug; crank; observe spark. Weak or intermittent spark → coil or contact problems.

Common pitfalls: Testing with 12V timing light on a 6V system; setting wrong points gap; not accounting for centrifugal advance/retard if present.

6) Carburetor (petrol) and governor/fuel injection pump (diesel) checks (20–60 min)
Petrol carburetor:
- Inspect for blocked jets, dirty float bowl. Remove and clean jets with carb cleaner. Ensure float level correct and accelerator pump (if fitted) operates.
- Check idle mixture and speed adjustments per manual. Listen for smooth idle and transition on throttle.

Diesel injectors and pump:
- Check injector spray: loosen injector line at injector (place rag and container), crank briefly—look for a fine, even cone spray. Poor spray = dirty or worn nozzle; replace or have nozzle cleaned/rebuilt.
- Check injector pump timing: static timing to flywheel marks or use a dial indicator as per manual. Incorrect timing causes rough running, smoke, or poor starting.
- Check for leaks at pump and seals. Replace filters and bleed system.

How to test injectors safely: Use gloves and eye protection, use a rag and container to catch diesel; high-pressure spray can be dangerous. If unsure, remove injectors and use a nozzle tester/bench.

Common pitfalls: Overtightening injector nuts damaging threads, incorrect pump timing after reassembly, failing to prime and bleeding air causing no-start.

7) Valves & mechanical inspection (30–90 min)
Tools: feeler gauges, socket/wrenches, possibly valve cover gasket.
- Set valve clearances cold to spec. Remove valve cover, rotate engine to TDC on cylinder 1 compression stroke, set clearances for that cylinder and others in firing order.
- Noisy valve train may indicate improper clearance or worn pushrods/rockers.

How to use feeler gauge: Insert gauge of correct thickness between rocker and valve stem; tighten lock nut to seat while holding gauge and recheck.

Common pitfalls: Using wrong clearance values; not tightening rocker lock nuts properly; missing sequencing.

8) Cooling & lubrication system checks (10–30 min)
- Check thermostat operation (if fitted). Overheating may be caused by blocked radiator, bad fan belt, or water pump failure. Inspect radiator fins and flush if required.
- Check oil pressure (if instrument available). Low oil pressure suggests worn bearings or oil pump problems. If low, stop running engine to avoid damage.

9) Running diagnostics and road/functional test (10–30 min)
- After fixes, start engine and observe idle, throttle response, smoke color (black = overfueling, white = unburnt fuel/coolant leak, blue = oil burning), exhaust smell.
- Test under load: raise front implements, operate PTO briefly, drive tractor to verify performance.
- Recheck for leaks, loose fittings, odd noises.

Common pitfalls summary
- Using 12V gear on 6V system (timing light, chargers).
- Not cleaning components before testing (dirt into carburetor/injectors).
- Overlooking air in fuel lines on diesel after replacing parts.
- Mis‑timing engine after adjustments.
- Using wrong valve/points clearance — can cause damage.
- Neglecting basic items (fuel filter, air filter) before advanced tests.

When replacement is usually required
- Spark plugs: replace if fouled, worn electrode, or cracked.
- Points & condenser: replace if pitted or aged.
- Coil: replace if no secondary spark or out-of-spec resistance.
- Fuel filters & hoses: replace when clogged or hardened.
- Injector nozzles/pump parts: replace or have serviced if spray pattern poor or pump leaks/pressure low.
- Gaskets, seals, head gasket: if compression test and coolant/combustion leak tests indicate.
- Bearings/pistons/rings: if compression test shows major wear and leakage persists.

Final advice (concise)
- Start with the simplest (fuel, air, battery) and progress to compression and ignition/injectors.
- Use correct‑voltage tools or static methods for timing on TE‑20’s 6V systems.
- Keep a service manual or factory spec sheet available for torque, clearances, and pressure specs—critical for accurate diagnosis and safe repairs.

End.
rteeqp73

Tools & supplies
- Feeler gauge set (metric and imperial)
- Open/box wrenches and sockets (common sizes 7/16–1/2 in; metric 10–13 mm)
- Screwdrivers (flat & Phillips)
- 2 wrenches for two‑nut adjusters or small spanner & screwdriver (depending on adjuster type)
- Socket and breaker bar (to turn crank) or long ratchet for flywheel/crank pulley bolt
- Torque wrench (for valve cover nuts)
- Spark plug socket & ratchet
- Small wire brush, rags, degreaser
- Replacement valve cover gasket
- Light oil (engine oil) and penetrating oil
- Flashlight or inspection mirror
- Gloves, safety glasses

Possible replacement parts (inspect and carry if needed)
- Valve cover gasket (always replace)
- Rocker arm bushings or studs (if worn)
- Pushrods (if bent or scored)
- Tappets/lifters (if worn)
- Valve stem seals, valve springs, valves (if leaking or damaged)
- Locknuts/adjusting screws if rounded or damaged

Safety precautions
- Work on a cold engine unless manual specifies “hot” lash setting. Cold reduces risk of burning and prevents wrong clearance due to thermal expansion.
- Park on level ground, engine off, key removed, parking brake on, wheels chocked.
- Disconnect battery (recommended) to avoid accidental starting.
- Remove spark plugs before rotating engine to make cranking easier and avoid accidental ignition.
- Keep hands, tools, and rags away from moving parts when cranking.
- Use eye protection and gloves.

Overview (what you’re doing)
- You are setting valve lash (clearance) so valves fully close and open correctly. Most TE‑20 engines use rocker arms with adjustable screws and locknuts over pushrods/tappets. Procedure: identify each cylinder’s compression stroke (both valves closed), set clearances with a feeler gauge for intake and exhaust, tighten locknuts, recheck.

Typical clearances (use these only if you don’t have the factory manual; verify if possible)
- Common ranges used on older MF 4‑cyl tractors: intake ≈ 0.20–0.25 mm (0.008–0.010 in); exhaust ≈ 0.30–0.35 mm (0.012–0.014 in). Confirm exact spec in your TE‑20 workshop manual and set cold unless manual calls for hot adjustment.

Step‑by‑step procedure
1. Preparation
- Park, chock wheels, set parking brake. Remove battery negative terminal (recommended).
- Remove hood/air cleaner if needed for access.
- Remove valve cover bolts and lift off valve cover. Clean mating surfaces; remove old gasket.
- Remove spark plugs and keep them safe.
- Clean any dirt around the rocker area so contaminants don’t fall into the engine.

2. Identify cylinder numbering and firing order
- Confirm TE‑20 cylinder numbering and firing order from manual (typical 4‑cylinder firing order 1‑3‑4‑2 but confirm). Knowing cylinder order is essential if you choose to follow the firing sequence method.

3. Turn engine to TDC on compression stroke for cylinder #1
- Use a socket on the crankshaft pulley/flywheel and slowly rotate engine in normal running direction.
- You want TDC (top dead center) on the compression stroke where both valves are closed and there is pressure on the tappet pushrods but rockers are at a neutral/closed position.
- How to confirm compression stroke:
- Look at the rocker arms: both intake and exhaust rockers for the cylinder should be loose (no lift) as you approach TDC; before TDC the intake may open then close; at TDC both valves are closed.
- Another method: feel for compression at spark plug hole (finger over plug or use a compression tester) or mark flywheel and count rotations from known position.
- If unsure, rotate one full turn (360°) from TDC and check again.

4. Set clearances on that cylinder
- With both valves closed at TDC compression, slide the correct thickness feeler gauge between the valve stem tip (or rocker contact) and the rocker adjusting screw/valve head area depending on the design.
- For rocker‑screw + locknut style:
- Loosen the locknut a turn.
- Hold the adjuster screw so it doesn’t turn, or hold screw with a screwdriver/Allen as appropriate.
- Turn the screw until you feel a slight drag on the feeler gauge when sliding it back and forth.
- While holding the screw in position, tighten the locknut to spec (or firmly but avoid overtightening). Recheck clearance after tightening (some locknuts can move the screw).
- For shims or bucket‑type lifters (less likely on TE‑20): follow manual procedure (usually requires removing rocker assembly and measuring shim thickness), don’t guess.

5. Repeat for intake and exhaust on that cylinder
- Intake and exhaust have different target clearances—set both.

6. Move to next cylinder using correct sequence
- Rotate crank 180° (or to next TDC on compression stroke for the next cylinder in firing order) and repeat the process.
- Continue until all cylinders are done.

7. Recheck all clearances
- After torquing all locknuts, go back and recheck each clearance. Tightening adjacent nuts can slightly alter settings.

8. Final assembly
- Clean valve cover mating surface. Install new gasket and valve cover. Torque cover bolts evenly to specified torque (or snug them evenly).
- Reinstall spark plugs, reconnect battery, reinstall air cleaner/hood.
- Start engine and run briefly, listen for excessive valve clatter (too loose) or snapping (too tight). Recheck and adjust if necessary.

How to use the feeler gauge properly
- Insert the blade between the rocker and valve stem (or specified contact points).
- Your feeler should slide with a slight resistance (“light drag”). If it slides too loosely the gap is too big; if it snags and you can’t slide it with slight pressure the gap is too small.
- Use the correct blade thickness for each valve (intake vs exhaust). Keep the gauge straight; don’t angle the blade.

Common pitfalls & how to avoid them
- Setting on the wrong stroke (exhaust stroke or overlap): always ensure TDC on compression stroke (both valves closed).
- Using wrong clearance spec: always confirm with factory manual. Wrong clearances cause noise, poor performance, or valve damage.
- Not rechecking after tightening locknuts: tightening can change the setting — always recheck.
- Over‑tightening locknuts/adjusters: risks stripping threads or bending adjuster. Tighten snugly, don’t crush threads.
- Bending pushrods by forcing rockers: ensure pushrods seat properly; if a pushrod is damaged replace it.
- Reusing old valve cover gasket: will leak oil. Always replace gasket.
- Working on a hot engine unless specified: thermal expansion leads to incorrect lash.
- Removing rocker shaft assembly without marking positions: if you remove components, mark shims/rockers to their original locations if you plan to reuse them; replacement parts may be needed if worn.

Troubleshooting after adjustment
- Loud clatter: lash too loose → re‑measure and tighten slightly.
- Tapping disappears but engine runs rough: lash too tight → valves may be held slightly open; re‑adjust.
- Persistent oil leak at valve cover: check gasket seating and bolt torque.
- Valve burning or low compression: excessive lash or other valve damage — perform a compression/check valve seats.

When to replace parts
- Replace any pushrod that is bent, scored, or has worn spherical ends.
- Replace rockers or bushings that show play or wear.
- Replace tappets/lifters if pitted or worn.
- Replace valve cover gasket whenever you open the cover.
- If a valve is sticky, burning, or seat is pitted, perform a valve job (regrind or replace valve/seat).

Final notes
- If you don’t have the TE‑20 workshop manual, get one or a reliable spec sheet and verify clearance, torque, and firing order before beginning.
- Work methodically, one cylinder at a time, and recheck. Proper valve lash is a simple but critical tune‑up that will extend engine life and restore performance.
rteeqp73