Carburetor Assembly 3303-812647T1 812647T1 812648T for Mercury Mariner 4 HP 5 HP 2 Stroke Outboard M MH ML MLH 1987-1998 — United Kingdom Local Warehouse
Carburetor Assembly 3303-812647T1 812647T1 812648T for Mercury Mariner 4 HP 5 HP 2 Stroke Outboard M MH ML MLH 1987-1998 — United Kingdom Local Warehouse
Product Overview
Carburetor assembly for Mercury and Mariner 4 HP and 5 HP two stroke outboards built from 1987 to 1998, supplied as 1 complete carburetor. It replaces 3303-812647T1 and 3303-812648T, and crosses to the bare numbers 812647T1, 812648T, 812647 and 8126471. Shipped from our United Kingdom local warehouse.
This is the whole carburetor, not a repair kit. On these small motors the body and the throttle shaft wear together, and a kit cannot restore a shaft that is already pulling air past the butterfly.
The model letters on the engine are the only reliable identification at this size. M, MH, ML and MLH cover the 4 HP and the 5 HP, and the cowlings look the same from the outside.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Outboard carburetor assembly |
| Horsepower | 4 HP and 5 HP |
| Engine Type | Two stroke outboard |
| Model Letters | M, MH, ML, MLH |
| Fitment Years | 1987 to 1998 |
| Quantity | 1 complete assembly |
OEM Cross Reference
| Brand | Part Numbers |
|---|---|
| Mercury | 3303-812647T1, 3303-812648T |
| Mercury | 812647T1, 812648T |
| Mercury | 812647, 8126471, 9628 |
| Mariner | 3303-812647T1, 3303-812648T |
Compatible Engines
| Output | Model | Years | Note |
|---|---|---|---|
| 4 HP | M | 1987 to 1998 | Two cylinder family |
| 4 HP | MH | 1987 to 1998 | Two cylinder family |
| 4 HP | ML | 1987 to 1998 | Two cylinder family |
| 4 HP | MLH | 1987 to 1998 | Two cylinder family |
| 5 HP | MH | 1987 to 1998 | Two cylinder family |
| 5 HP | ML | 1987 to 1998 | Two cylinder family |
| 5 HP | MLH | 1987 to 1998 | Two cylinder family |
What's Included
| Component | Qty |
|---|---|
| Carburetor assembly 3303-812647T1 | 1 |
When a Repair Kit Is Not Enough
| Symptom | Likely Cause | What Actually Fixes It |
|---|---|---|
| Idle will not stay set, mixture screw has no effect | Throttle shaft worn, air past the butterfly | Complete carburetor, a kit will not seal the shaft |
| Motor runs lean at half throttle | Body worn at the venturi or a blocked jet | Complete carburetor plus a clean fuel supply |
| Fuel weeping at the bowl joint again | Warped bowl face from overtightening | Complete carburetor and a new base gasket |
| Starts and dies as soon as the choke comes off | Idle circuit blocked inside the body | Strip and clean, or renew if the body is worn |
| Engine surges and the plug reads lean | Air leak at the base gasket | New gasket first, then recheck before renewing |
| Boat sat for two seasons with fuel in it | Varnish through the idle circuit | Clean first, renew if it will not hold a setting |
Fuel, Ethanol and the Lay-Up
| Situation | Effect on the Carburetor | What to Do |
|---|---|---|
| E10 petrol in a UK forecourt | Ethanol draws water and attacks older rubber parts | Use E5 where possible, drain if the boat is stored |
| Fuel left in the bowl over winter | Varnish sets in the idle circuit | Run the bowl dry before lay up |
| Coastal use and salt air | Corrosion on the linkages and the bowl screws | Rinse the cowling area, oil the linkage |
| Engine used a few times a season | Fuel goes stale between trips | Fresh fuel each trip, drain the bowl after use |
| Cold starting below 5 °C | Choke needed longer, idle weak until warm | Let it warm before setting the idle |
| Primer bulb left pressurised | Needle and seat held loaded, flooding | Release the bulb when the motor is not running |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Read the model letters M, MH, ML or MLH off the engine, the 4 HP and 5 HP cowls look the same |
| 2 | Match the old carburetor against 812647T1 or 812648T before ordering |
| 3 | Count the turns on the old mixture screw, that is where the new one starts |
| 4 | Fit a new base gasket, an air leak at the base is the usual reason a new carburetor will not idle |
| 5 | Check the fuel line, primer bulb and filter for air leaks before blaming the carburetor |
| 6 | Check the throttle linkage travels fully open and returns without binding |
| 7 | Set the idle in a tank or on the water, not on muffs |
| 8 | Recheck the plug colour after the first hour of running |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Shipping from the United Kingdom
| Destination | Warehouse | Note |
|---|---|---|
| United Kingdom | United Kingdom local warehouse | Domestic delivery, no import duty |
| Ireland | United Kingdom local warehouse | Short transit, customs may apply |
| Channel Islands | United Kingdom local warehouse | Tracked shipping available |
Before You Buy
- Check the model letters M, MH, ML or MLH, the 4 HP and 5 HP cowls look identical
- Match the old carburetor against 812647T1 or 812648T
- Count the turns on the old mixture screw before it comes off
- Fit a new base gasket, an air leak there stops any carburetor idling
- Check the fuel line and primer bulb for air leaks first
- This is the complete carburetor, the base gasket and fuel lines are not included
- 30-Day Easy Returns
- Ships from our United Kingdom local warehouse
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