Drain Plug 22-16951Q1 22-16951A1 for MerCruiser Exhaust Manifold Engine Block Brass 1/4 Pipe
Drain Plug 22-16951Q1 22-16951A1 for MerCruiser Exhaust Manifold Engine Block Brass 1/4 Pipe
Product Overview
Exhaust manifold and engine block drain plug, a direct replacement part for MerCruiser engines from the 1970s, 1980s and early 1990s. It replaces MerCruiser 22-16951Q1, 22-16951A1, 22-16951T1, 22-64426 and 22-87238, crosses to Sierra 18-4218, Volvo Penta 82745 and OMC 379957, and has a 1/4 pipe thread. Supplied as one brass plug with the petcock valve fitted, packed in a 150 mm x 180 mm x 30 mm box (5.91 in x 7.09 in x 1.18 in) at 46 g.
The petcock is the small tap on the end of the plug. Open it and the block drains through the nipple instead of dropping water into the bilge every time the plug comes out.
GM V6 and V8 blocks use one of these on each side, so a full winterise takes two. Four cylinder engines use one plug, and some exhaust manifolds have a drain port that takes the same brass fitting.
These plugs seize. A brass plug left in an iron block for a few seasons will not come out with a spanner, and a snapped petcock leaves the block undrainable. Replace it before the freeze rather than after.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Engine block and manifold drain plug |
| MerCruiser Part Numbers | 22-16951Q1, 22-16951A1, 22-16951T1, 22-64426, 22-87238 |
| Sierra Cross Reference | 18-4218 |
| Volvo Penta Cross Reference | 82745, 82744, 82745-1 |
| OMC Cross Reference | 379957 |
| Thread | 1/4 pipe |
| Material | Brass |
| Fits | MerCruiser blocks and exhaust manifolds, 1970s to early 1990s |
| Package Contents | 1 x brass plug and petcock assembly |
| Country of Origin | Taiwan |
| Net Weight | 46 g including packaging |
| Pack Size | 150 mm x 180 mm x 30 mm |
| Pack Size In Inches | 5.91 in x 7.09 in x 1.18 in |
| Warranty | 3 year |
OEM Cross Reference
| Brand | Part Numbers |
|---|---|
| MerCruiser | 22-16951Q1, 22-16951A1 |
| MerCruiser | 22-16951T1, 22-64426, 22-87238 |
| Sierra | 18-4218 |
| Volvo Penta | 82745, 82744, 82745-1 |
| OMC | 379957 |
Compatible Engines
| Engine | Drain Points | Where |
|---|---|---|
| GM V8 blocks | 2 | One on each side of the block |
| GM V6 blocks | 2 | One on each side of the block |
| GM four cylinder blocks | 1 | Single block drain |
| MerCruiser exhaust manifolds | Varies | Drain port on the manifold |
| MerCruiser engines 1970s to early 1990s | Varies | Block and manifold drainage |
What's Included
| Component | Detail | Qty |
|---|---|---|
| Brass drain plug valve female | 1/4 pipe thread into the block | 1 |
| Brass drain plug valve male | Petcock body with the tap | 1 |
| Washer or seal | Not included | 0 |
Signs The Drain Plug Needs Replacing
| What You See | What It Means | What To Do |
|---|---|---|
| Petcock will not turn | Valve seized with corrosion | Fit the new plug |
| Petcock snapped off | Brass fatigued in the block | Fit the new plug |
| Water will not drain | Passage blocked inside the valve | Fit the new plug |
| Weeping round the thread | Thread or seat corroded | Fit the new plug |
| Plug rounded off on the hex | Seized and forced | Fit the new plug |
| Rust stains down the block | Slow leak from the petcock | Fit the new plug |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the old plug against the table above |
| 2 | Drain the cooling system before removing anything |
| 3 | Take the old plug out and clean the thread in the block |
| 4 | Check the seat for rust scale and pitting |
| 5 | Fit the new brass plug with a thread sealant suited to brass in iron |
| 6 | Tighten to seat the plug, do not force it past that point |
| 7 | Refill the cooling system and run up to temperature |
| 8 | Check for weeping round the plug, then winterise as normal |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | 3 year |
| Packaging | Sealed retail packaging |
Before You Buy
- Fits MerCruiser blocks and manifolds from the 1970s to early 1990s
- Replaces MerCruiser 22-16951Q1 and 22-16951A1
- Crosses to Sierra 18-4218, Volvo Penta 82745 and OMC 379957
- 1/4 pipe thread, brass body
- One plug per side on GM V6 and V8 blocks
- Four cylinder engines use one plug
- 46 g with packaging, box 150 mm x 180 mm x 30 mm
- Check the thread size before ordering
- 30-Day Easy Returns
- Ships from our warehouse with tracking
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Before You Buy
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