Carburetor 8M0109535 853720T21 for Mercury Outboard 2 Cyl Carb Engines 10HP 15HP 20HP
Carburetor 8M0109535 853720T21 for Mercury Outboard 2 Cyl Carb Engines 10HP 15HP 20HP
Product Overview
Carburetor 8M0109535 for Mercury two cylinder carbureted outboards in 10HP, 15HP and 20HP, the complete carburetor part that bolts on in place of 853720T21 and 853720T15. It comes in a 155 mm x 105 mm x 100 mm box at 652 g and is also listed for OMC engines using the same carburetor.
This is a whole carburetor rather than a rebuild kit, so there is no cleaning, no gasket set and no float height to set before it goes back on. That suits the motor where the throttle shaft is worn or the body has been eaten by salt water and a rebuild would not hold.
Check the old carburetor against the photos before ordering. Two cylinder Mercury motors of this size came with more than one calibration, and the number on the flange is what settles it.
Specifications
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Outboard carburetor |
| Replaces | 8M0109535, 853720T21, 853720T15 |
| Fits | Mercury two cylinder carbureted outboards 10HP, 15HP and 20HP |
| Also Listed For | OMC engines using the same carburetor |
| Fuel System | Two cylinder carbureted |
| Package Contents | 1 x carburetor |
| Country of Origin | Taiwan |
| Net Weight | 652 g including packaging |
| Pack Size | 155 mm x 105 mm x 100 mm |
| Pack Size In Inches | 6.10 in x 4.13 in x 3.94 in |
| Warranty | 3 year |
OEM Cross Reference
| Component | OEM Part Numbers |
|---|---|
| Carburetor | 853720T21 |
| Carburetor, later number | 8M0109535 |
| Carburetor, alternate number | 853720T15 |
Compatible Engines
| Brand | Horsepower | Engine Type |
|---|---|---|
| Mercury | 10HP | Carb 2 Cyl. |
| Mercury | 15HP | Carb 2 Cyl. (JCI) |
| Mercury | 20HP | Carb 2 Cyl. |
| OMC | Same carburetor applications | Two cylinder carbureted |
What's Included
| Component | Detail | Qty |
|---|---|---|
| Carburetor assembly | Complete, as pictured | 1 |
| Gaskets and studs | Not included, reuse or renew the originals | 0 |
Signs The Carburetor Needs Replacing
| What You See | What It Means | What To Do |
|---|---|---|
| Motor will not idle without choke | Idle circuit blocked or body corroded | Fit the new carburetor |
| Rough running at low speed | Worn throttle shaft letting air past | Fit the new carburetor |
| Fuel leaking from the body | Seat or float chamber corroded through | Fit the new carburetor |
| Motor surges then dies | Float level cannot be set, body worn | Fit the new carburetor |
| Black plugs after every trip | Over fuelling from a worn needle | Fit the new carburetor |
| Adjustment screws no longer respond | Passages blocked beyond cleaning | Fit the new carburetor |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the model and the number on the old carburetor |
| 2 | Disconnect the battery and close the fuel tap |
| 3 | Take off the cowling and note the linkage and fuel line routing |
| 4 | Remove the old carburetor and clean the mounting face |
| 5 | Fit the new carburetor with fresh gaskets |
| 6 | Reconnect the fuel line, throttle and choke linkage |
| 7 | Squeeze the primer bulb and check for leaks |
| 8 | Start on muffs, set the idle mixture and check the plugs after the first run |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | 3 year |
| Packaging | Sealed retail packaging |
Before You Buy
- Fits Mercury 10HP, 15HP and 20HP two cylinder carbureted outboards
- 15HP application is the JCI version
- Replaces 8M0109535, 853720T21 and 853720T15
- Also listed for OMC engines using the same carburetor
- One complete carburetor, gaskets are not included
- Compare the old carburetor against the photos
- 30-Day Easy Returns
- Ships from our warehouse with tracking
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Boat Owners' Review
Before You Buy
Frequently Asked Questions
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