SPECIFICATIONS

Size .65

Bore 0.938

Stroke 0.94

HP 1.1

RPM 2,000 ~ 12,500

Weight 17.5 oz

Part No. 5800 - K&B .65 Sportster Engine

WARNING

PLEASE READ ALL SAFETY INSTRUCTIONS! Failure to read, understand and follow these instructions could result in personal 

injury and/or property damage to yourself or others. 

Take a few moments to familiarize yourself with the various parts of the engine. DO NOT DISASSEMBLE YOUR ENGINE! Doing so 

will void your warranty. No exceptions! 

-

ENGINE BREAK-IN

It is unnecessary to give the engine a prolonged break-in. However, we suggest that you mount your engine to a break-in stand to 

familiarize yourself with it and with the carburetor operation. It is strongly recommended that fuels containing more than 15%

nitromethane be avoided until after the engine has been in operation for about an hour on a mild fuel, and under mixture-rich 

conditions. Mixture-rich operation is when the engine has a slight “burbling” sound and probably a very smoky exhaust. This helps 

lubrication and cooling when the engine is new. 

Typically, an engine will be ready for full-throttle and mixture-lean operation after less than an hour of running. When the engine holds 

R.P.M. after the mixture has been leaned out ... when R.P.M.’s don’t sag after a moment or so ... the engine can be considered to be 

broken in. 

ENGINE and FUEL TANK INSTALLATION

The engine may be installed upright, on either side, or inverted (upside down). The 1/4 inch diameter output shaft mounts standard 

hole-size propellers. 

Mount the engine firmly to hardwood rails, or to the firewall, if you use a radial mount. For maximum security, use carbon steel, selflocking hex nuts and hardened alloy steel machine screws to mount the engine. The fuel tank size, location, and height have a great 

influence on engine operation. It should be located close to the engine. For carburetor engines, locate the tank so that its horizontal 

centerline is from 1/4” to 3/8” below the fuel connection to the carburetor.

STARTING THE ENGINE

With a full tank of fuel, the recommended propeller installed, and a fully-charged booster battery of no more than 1.5 volts ready for 

connection to glow plug, proceed as follows to manually start an engine installed in a plane. 

NOTE: To avoid burning out the glow plug, never use a booster battery of more than 1.5 volts. The battery is used to heat the glow

plug coil only during engine starting. After the engine has started and is running smoothly, the booster battery is disconnected. Heat 

from the burning mixture in the cylinder keeps the coil hot. 

1. With the booster battery disconnected, turn the needle valve counter-clockwise 2-1/2 turns from the fully closed position. 

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2. With the booster battery still disconnected and with the throttle wide open, place finger tip over the carburetor inlet and flip the 

propeller quickly 2 or 3 times, to prime the engine. 

3. Remove finger tip from the carburetor inlet then close the throttle to a fast idle setting and again flip the propeller quickly 2 or 3 

times. 

4. Connect the booster battery clip to the glow plug. 

NOTE: Make sure you are holding your airplane firmly to prevent it from lurching forward when the engine starts. After it starts, 

maintain your hold until you have reduced the throttle to a low idle speed. 

5. Slowly turn the propeller (counter-clockwise) and “feel” for a momentary resistance, which indicates ignition of the mixture in the 

cylinder. 

6. Quickly flip the propeller to start the engine and then disconnect the booster battery. 

7. Except for the first hour or so, as noted under “Engine Break-in”, adjust the needle valve by turning clockwise to lean the mixture 

for full power operation. If the R.P.M. starts to sag (back-off) you have leaned the mixture too much and you should then turn the 

needle valve counter-clockwise until the R.P.M. picks up and holds steady.

PROPELLERS

A 11" x 7p propeller is recommended as a starting size. However, experimenting with one pitch or diameter larger or smaller can 

improve results for your particular airplane.

CARBURETOR OPERATING INSTRUCTIONS

The carburetor enables easy adjustment of both the idle speed, idle mixture and the high speed mixture.

1. High Speed Needle Valve - Locate an area to install the Remote Needle Valve Assembly using the bracket provided. This may 

typically be attached to the firewall, cowl, or rear engine mount lug area. This assembly must be in the fuel line between the tank and 

the carburetor. The line should not exceed five (5) inches in total length.

2. High Speed Needle Valve Adjustment - This needle valve, located on the Remote Needle Valve Assembly, controls all the fuel 

that comes to the engine, whether the engine is running at high, mid-range, or idle speeds. It does not affect the low speed 

rich/lean setting. The High Speed Needle Valve's main function, however, is to meter the high-speed fuel mixture.

As a starting point for the High Speed Needle adjustment, completely close the needle valve (clockwise), then open it (counterclockwise) three and a half-turns. This setting is an average and may require further adjustments. For higher altitudes (3,000 - 4,000 

feet), close the needle valve approximately 1/2 turn.

3. Low Speed and Mid-range Adjustment - 

The rich/lean adjustment is controlled by the "slotted" screw located on the side of the carburetor where the low speed disk is 

housed. The rich/lean mixture control is set at the factory and may require only a "fine" adjustment for your application. WARNING: 

DO NOT RUN THE ENGINE AT A "LEAN" SETTING. This screw only turns 1/4 turn to either the right or left of center. It does not 

turn all the way around. Turn the screw clockwise to "lean" the engine and counter-clockwise to richen the mixture.

GLOW PLUGS

This engine comes equipped with a standard Long Reach Glow Plug (K&B No. 7311). Performance will vary, depending on the glow 

plug and fuel used.

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