Replacement primer bulb sized D.I. x O.D. x HT: 0.512' x 0.75' x 0.56' Key benefits Ensures a correct, snug fit for carburettors that require these dimensions, restoring reliable priming and consistent fuel delivery. Reduces starting issues by restoring proper suction and sealing where a worn or damaged bulb caused fuel leaks or air ingress. Straightforward replacement that minimizes downtime and avoids the need for full carburettor replacement. Function and performance Designed to function as the primer bulb for carburettors, supplying the initial fuel push to the carburettor bowl for faster, more reliable starts. Precise dimensions (D.I. x O.D. x HT: 0.512' x 0.75' x 0.56') ensure consistent performance and repeatable sealing. Intended for practical field and use where accurate fit and dependable priming are required. Compatibility and size For carburettors using a 3/4' outer diameter primer bulb, 9/16' height. Compatible with models: 18812, 188121, 18814, 188141. Exact sizing listed above; verify these dimensions against your existing primer bulb before ordering. Use scenarios Routine maintenance: a brittle or cracked primer bulb during seasonal service to restore reliable starting on small engines. Quick field : Carry as a spare for onsite repairs to get equipment back into service quickly when the original primer bulb fails. rebuilds: Use during carburettor rebuilds on units that require the listed dimensions and model compatibility. Additional notes Confirm compatibility by matching the listed dimensions and model numbers to your carburettor. Supplied as the single replacement primer bulb sized and specified above.