6 Best Craftsman Lawn Mower Won’t Start No Primers (2026): Our Picks

By Graham Fisher

Updated November 2026

A craftsman lawn mower won’t start no primer situation usually means the primer bulb has cracked, hardened, or lost its seal, so fuel never gets pulled into the carburetor on the first pulls. Replacing the bulb is one of the cheapest repairs on a small engine, but the part number has to match your engine family, and the fit is where many buyers run into trouble. This guide covers six primer bulb and carburetor-assembly options sold on Amazon US, grouped by fit, included hardware and the engine families each one is listed for. The selection criteria were compatibility with Briggs & Stratton and Craftsman/MTD-style engines, how clearly each listing names its model numbers, and the patterns owners tend to mention in their feedback about leaks and seating.

Our Top Picks

The table below summarizes the six products. Read the individual sections before buying, because several of these parts only fit specific engine families.

Primer Bulb 694394 Replacement for Briggs & Stratton 4178 494408 5084 Lawn Mower Carburetor

Primer Bulb 694394 Replacement for Briggs & Stratton 4178 494408 5084 Lawn Mower Carburetor

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Best for: Overall fit for owners who have already matched their engine to a 694394 or 494408 part number.

This is a direct-replacement primer bulb for Briggs & Stratton carburetors that list 4178, 494408 or 5084 as cross-references. It suits someone who has pulled the old bulb, read the number stamped on it, and confirmed it matches.

Key specs

• Replaces primer bulb 694394
• Cross-referenced to 4178, 494408 and 5084
• Designed for Briggs & Stratton lawn mower carburetors

Pros

• Part number matches the cross-reference list directly
• Single-bulb packaging keeps the purchase simple
• Installs without modifying the carburetor body

Cons

• Fit depends entirely on confirming your engine’s cross-reference
• Only one bulb per order

Bottom line: The best choice for an owner who has verified a 694394 or 494408 number and wants a straightforward swap.

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594281 Lawn Mower Carburetor Primer Bulb for Briggs & Stratton 300E 450E 500E 08P502 09P6 Series

594281 Lawn Mower Carburetor Primer Bulb for Briggs & Stratton 300E 450E 500E 08P502 09P6 Series

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Best for: Briggs & Stratton 300, 450 and 500 series engines.

This bulb is listed against specific Briggs & Stratton series designations, which makes it easier to match than a generic part number when your engine’s model plate is readable.

Key specs

• Replaces part 594281
• Listed for 300E, 450E, 500E and 08P502 / 09P6 series engines

Pros

• Series-based listing is easy to cross-check against the engine plate
• Targets a common walk-behind engine family
• Replacement is a quick job with basic hand tools

Cons

• Not suitable for engines outside the listed series
• Owners should still confirm the bulb seats fully before reinstalling

Bottom line: A strong pick for owners whose engine plate reads 300E, 450E or 500E.

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Hipa 2 Pack 951-10888A 570682A Primer Bulb Fits for Craftsman MTD Cub Cadet Troy Bilt Yard Machine

Hipa 2 Pack 951-10888A 570682A Primer Bulb Fits for Craftsman MTD Cub Cadet Troy Bilt Yard Machine Snow Blower 951-10639A 951-10888B 751-10888 Primer Bulb Assembly for Tecumseh HMSK100 HMSK105 HMSK110

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Best for: Households or shops that maintain several MTD-family mowers.

The listing covers a wide range of MTD-built machines sold under Craftsman, Cub Cadet, Troy Bilt and Yard Machine names, plus Tecumseh-family engine references. Two bulbs in one pack means a spare is on hand.

Key specs

• Two-pack primer bulb assembly
• Lists 951-10888A, 570682A, 951-10639A, 951-10888B and 751-10888
• Cross-listed for Tecumseh HMSK100, HMSK105 and HMSK110

Pros

• Covers many brand names built on the same MTD platform
• Spare bulb included
• Broad cross-reference list helps with older or unlabeled machines

Cons

• Broad compatibility means matching the exact number still matters
• Some owners report that bulbs from multi-fit packs need a light trim to seat

Bottom line: Best for multi-machine households where one order can cover more than one mower.

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795259 Air Filter Cleaner Primer Base Replacement for Craftsman Lawn Mower Motor

795259 Air Filter Cleaner Primer Base Replacement for 792040 691753 496116 224815 Most 122000 Model Engine Mower Craftsman Lawn Mower Motor

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Best for: Engines where the primer is integrated into the air filter base rather than mounted separately.

On some Craftsman and other MTD-family engines, the primer sits in the air cleaner base. Replacing the base is then the correct repair, and this listing matches several engine part numbers in that category.

Key specs

• Replaces part 795259
• Cross-referenced to 792040, 691753, 496116 and 224815
• Listed for Craftsman lawn mower motors with model 122000 references

Pros

• Replaces the primer and its mounting base in one part
• Multiple cross-reference numbers help with matching
• Useful when the bulb itself is fine but the base has cracked

Cons

• Requires removing the air cleaner cover and some disassembly
• Only the right engine family will accept this base

Bottom line: Pick this if your primer is part of the air filter housing and you are seeing cracks or leaks at the base.

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E-YooHoo Set of 2, 694394 Replacement Lawn Mowers Carburetor Primer Bulb for Briggs & Stratton 4178 494408 5084

E-YooHoo Set of 2, 694394 Replacement Lawn Mowers carburetor Primer Bulb for fits Briggs & Stratton 4178 494408 5084

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Best for: Budget repairs and keeping a spare on the shelf.

This is the same 694394 cross-reference family as the top pick, sold as a two-pack. For owners who want a spare bulb or are repairing more than one engine, it is an economical way to stock up.

Key specs

• Set of two primer bulbs
• Replaces 694394 with 4178, 494408 and 5084 cross-references

Pros

• Two bulbs per order
• Same cross-reference coverage as the single-bulb option
• Good value for owners who keep spares

Cons

• Fit is limited to the 694394 family
• Bulb quality varies between listings, so inspect on arrival

Bottom line: A sensible budget pick for owners who have verified the 694394 number and want a spare.

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799866 Carburetor with Air Filter Spark Plug Primer Bulb for 675 Series, Toro, Troy Bilt and Craftsman 190cc Engines

799866 Carburetor with Air Filter Spark Plug Primer Bulb For 675 6.75 Series 90845 794304 799871 796707 790845 Engines Toro 20332 Troy Bilt TB230 Lawnmower Craftsman 190cc hp Engine

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Best for: Full carburetor replacement on 675-series, 190cc and selected Toro or Troy Bilt engines.

Instead of replacing just the bulb, this listing is a complete carburetor assembly that includes an air filter, spark plug and primer bulb. It is intended for owners who find the carburetor itself is clogged or damaged beyond cleaning.

Key specs

• Complete carburetor with air filter and primer bulb
• Cross-listed for 675 and 6.75 series engines, including 90845, 794304, 799871, 796707 and 790845
• Listed for Toro 20332, Troy Bilt TB230 and Craftsman 190cc engines

Pros

• Replaces several components at once
• Covers a broad range of engines in the 675 family
• Useful when the carburetor body, not just the bulb, is the problem

Cons

• More involved installation, including linkage and fuel-line work
• Overkill if only the primer bulb has failed

Bottom line: Choose this for a complete carburetor swap on a compatible 675-series or 190cc engine, not as a first step for a simple primer problem.

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Buying Guide

Before you order any part, a few checks will save a return. Most no-primer problems come down to the bulb, the base, or fuel reaching the carburetor, so match the part to what you find.

Confirm your engine model and part number

Look for the model and code plate on the engine, usually on the blower housing or the top of the engine shroud. Write down the model, and note the cross-reference numbers printed on the old primer bulb if it is still readable. A bulb that matches a cross-reference is far more reliable than one matched only by brand.

Good picks for this: Primer Bulb 694394 Replacement for Briggs & Stratton 4178 494408 5084 Lawn Mower Carburetor, 594281 Lawn Mower Carburetor Primer Bulb

Decide between a bulb and a full carburetor

If the bulb is cracked, hard or leaking air, replacing only the bulb is usually enough. If the bulb is fine but the engine still will not draw fuel, the carburetor may be clogged, and a complete assembly makes more sense. Check the fuel bowl and jets before you commit to a full part.

Good picks for this: 799866 Carburetor with Air Filter and Primer Bulb, Primer Bulb 694394 Replacement

Check whether the primer sits on the air filter base

On some Craftsman and MTD-family mowers, the primer is molded into the air cleaner base. If removing the air filter cover reveals the primer as part of the plastic housing, you need a base replacement rather than a loose bulb.

Good picks for this: 795259 Air Filter Cleaner Primer Base Replacement for Craftsman Lawn Mower Motor

Consider how many machines you maintain

A single mower may only need one bulb, but a household with several MTD-family machines benefits from multi-fit packs. Buying two bulbs at once also gives you a spare for the next season, which is handy because primer bulbs harden with age and exposure to fuel.

Good picks for this: Hipa 2 Pack 951-10888A Primer Bulb Assembly, E-YooHoo Set of 2, 694394 Replacement Primer Bulb

Inspect the bulb and seat before installing

A new bulb that does not seat fully will leak air and prevent priming. Compare the new bulb to the old one, check the nipple and the mounting surface, and make sure the bulb sits flush. A small trim on the mounting edge is sometimes needed on multi-fit parts, but avoid forcing a bulb that does not fit its seat.

Good picks for this: 594281 Lawn Mower Carburetor Primer Bulb, Hipa 2 Pack 951-10888A Primer Bulb Assembly

Check fuel condition and the fuel line

Old gasoline is a common cause of no-start complaints, even with a good primer. Stale fuel can gum the carburetor and block the bulb’s fuel path. If the mower has sat for a season, drain or replace the fuel, and check the fuel line for cracks before you assume the primer is at fault.

Good picks for this: 799866 Carburetor with Air Filter and Primer Bulb, Primer Bulb 694394 Replacement

Work safely around fuel and the spark plug

Disconnect the spark plug wire before working on the carburetor, and work in a ventilated area away from open flame. Gasoline vapor is flammable. If you are not comfortable with fuel system work, consult a qualified small-engine technician.

Good picks for this: 795259 Air Filter Cleaner Primer Base Replacement, 799866 Carburetor with Air Filter and Primer Bulb

FAQ

Why won’t my Craftsman mower start without primer?

The most common reason is a cracked, hardened or leaking primer bulb that cannot pull fuel into the carburetor. Other causes include stale fuel, a clogged carburetor, a dirty air filter, or a spark plug that is fouled or disconnected. Check the bulb first, then the fuel and spark.

How do I know if my primer bulb is bad?

Press the bulb several times. A good bulb feels firm and springs back, and fuel should appear in the line or bowl after a few presses. A bulb that stays collapsed, feels soft or hard, or shows cracks should be replaced.

Can I use any primer bulb on my Craftsman mower?

No. Primer bulbs differ by engine family, and Craftsman mowers use Briggs & Stratton, MTD-family or other engines depending on the model. Match the part number on your old bulb or the model number on the engine plate to a listed cross-reference before buying.

Does a primer bulb replacement require removing the carburetor?

On many engines the bulb can be swapped without fully removing the carburetor, but access varies. Some primers are mounted on the air cleaner base, which requires removing the air filter cover. Check your engine’s layout before starting.

Should I replace the bulb or the whole carburetor?

Start with the bulb if it is cracked or leaking. If the bulb is sound and the engine still will not draw fuel, the carburetor may be clogged or damaged, and a complete carburetor assembly may be the better choice. Clean the carburetor first if you are unsure.

How long do primer bulbs last?

There is no fixed lifespan. Bulbs can harden or crack after several seasons, especially if the mower sits with old fuel in the system. Inspecting the bulb each spring is a simple habit that prevents a no-start surprise.

When should I take the mower to a technician?

If you have replaced the bulb, checked the fuel and spark plug, and the engine still will not start, or if you find fuel leaks or damaged housings, consult a qualified small-engine technician. Fuel system work carries fire and exposure risks that a professional can handle safely.

Conclusion

For most owners whose craftsman lawn mower won’t start no primer problem comes from a failed bulb, the best starting point is a direct-replacement bulb matched to a verified part number. The Primer Bulb 694394 Replacement is the strongest overall choice when the 694394 or 494408 cross-reference applies to your engine. The 594281 bulb suits Briggs & Stratton 300E, 450E and 500E series mowers, while the Hipa 2 Pack covers households with several MTD-family machines. If the primer is molded into the air filter base, the 795259 base is the correct repair. The E-YooHoo two-pack is a practical budget option for spares, and the 799866 complete carburetor assembly is for owners who have ruled out a simple bulb failure on a compatible 675-series or 190cc engine. Confirm your model and part number before ordering, and the right part should be an easy repair.

Sources

• Consumer safety guidance on handling gasoline and small-engine equipment (cpsc.gov)
• Workplace safety standards for flammable liquids and fuel handling (osha.gov)
• Guidance on small off-road engines, fuel handling and emissions (epa.gov)

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About Graham Fisher

Graham Fisher is part of our editorial team and reviews and edits our lawn mowers guides, checking product details against manufacturer specifications and owner feedback.