Mercury Technical Database

Mercury 9.8hp (Blue Stripe)

Name: Mercury 9.8hp (Blue Stripe) Outboard Motor (1978)
Brand: Mercury
Availability: OutOfStock

9.8 HP 1978 2-Stroke Discontinued ✓ Service Data Verified

Smaller Model 9.8hp (2-Stroke)

Current Model 9.8hp (Blue Stripe)

Larger Model 9.9hp (2-Stroke)

General Specifications

HP / kW 9.8 HP / 7.3 kW

Displacement 180 cc (11.0 cu in.)

Cylinders 2 (Inline)

WOT RPM 4500 - 5500

Weight 30 kg / 66 lbs

Drive & Lower Unit

Gear Ratio 2.00:1

Shaft Length 15", 20"

Electrical System

Alternator Output None / Magneto Only

Starting System Manual

Technical Maintenance Toolkit

Verified service specifications for the Mercury 9.8hp (Blue Stripe) (1978)

Lubrication

Engine Oil

50:1 Pre-mix

Gearcase Lube 200 ml

Ignition System

Spark Plug

NGK BP7HS

Gap Setting 0.040"

Firing Order 1-2-3-4

Performance Specs

Idle RPM 700 ± 50

WOT Range 4500-5500

Alternator None

Standard Maintenance Intervals

20H Break-in Service

100H Annual Tune-up

300H Water Pump & Seals

Identification

The serial number for the Mercury 9.8hp (Blue Stripe) is typically found on a plate located on the transom bracket.

Technical Toolkit

Compare this 9.8HP engine → Identify your model year → Decode error codes → Propeller guide for this 9.8HP →

Maintenance Compatibility

These models share common service parts with the Mercury 9.8hp (Blue Stripe):

Model Evolution

History of the Mercury 9.8HP series over the years:

1990 9.8hp (2-Stroke)

Category Discovery

All 9.8HP Motors Full Mercury Index 1970s Archive

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Reference Data

Information compiled from Mercury Marine factory service manuals and original sales literature published in 1978.