(Service Bulletin RE9 contained the complete midyear revision to tuning procedures.
These are the recommended procedures for tuning any RE5.
As with bulletins RE-1 through RE-16, the number had no connection with the name of the bike, it was just the chronological order of the bulletins.
Table of Contents for all Bulletins)



This bulletin contains the latest information necessary to correctly service the RE5 after it has been set up.

This bulletin is designed to cover the latest carburetor protractor, throttle cables, throttle grip, carburetor specifications, and adjustment shortcuts.

Proper empoyment of the procedures outlined in this bulletin will ensure you of the smoothest possible running RE5


If the Carburetor Modification Kit (99104-09050) has not been installed, install it first in accordance with Service Bulletin #RE-8 before proceeding with the servicing of the RE5.


Use ONLY Suzuki Rotary Engine Motor Oil 10W-20W-50 or Shell Super X 10W-20W-50 in the Sump AND Metering Pump Oil Tank. Use of other than recommended oils may cause engine damae and possibly void the warranty.

(Note: Suzuki brand Oil was a promotional gimmick; today the oil recognized as best for the RE5 is Castrol 20W-50; its low ash content minimizes buildup inside the power unit.)


Use ONLY unleaded regular or low-lead regular gasoline.


  1. Fill with dilute sulfuric acid with a specific gravity of 1.280 (as corrected to 20 degrees C.)
  2. Charge the battery at a rate of 1.0 to 1.5 amps for 20 hours.

NOTE: Charge the battery with the battery on the bench. Leave the vent tube in the frame. DO NOT OVERFILL. After charging, bring the battery cells up to the full mark with distilled water.


Check the coolant level. If low bring it up to the plate with a 50% mixture of Golden Cruiser #1200 and distilled water.

(comment on antifreeze)


  1. Place the RE5 on the centerstand.
  2. Drain the transmission and replace the drain plug.
  3. Install 1600cc of the specified oil in the transmission.

(comment on filling trans oil)


A. Metering Pump Oil Tank:

Fill the metering pump oil tank with one of the two recommended oils.

(comment on oil, filling)

NOTE: Always ensure that nothing is placed on top of the oil tank cap vent hole such as gloves, maps, etc.

Bleed the metering pump oil line with the bleeder screw on the pump.

B. Engine Sump:

  1. Place RE5 on center stand
  2. Fill the sump to the "Full" mark on the dip stick.
  3. Start the engine and let it idle until the temperature gauge reaches the center mark.
  4. Shut the engine off and wait 15 minutes.
  5. Recheck the oil level and bring it to the "Full" mark.

NOTE: ALWAYS follow this procedure when checking the sump oil level on the RE5, otherwise accurate measurements cannot be obtained.


  1. Remove the left side alternator cover "SUZUKI" emblem and the rubber plug under it.
  2. Insert a 17mm T-handle through the hole and on to the head of the alternator rotor fitting bolt.
  3. Remove the breaker housing cap on the right side of the engine.
  4. Remove the nylon point covers.
  5. Clean the contact point faces if neccesary. Inspect for oil, burning, and pitting.

    a. File the points faces with a #120 grit flex-stone, .024" thick

    b. Clean the point faces off with electrical contact cleaner

    c. Blow the point faces off with compressed air

    d. Draw a strip of thin slick card board (business card) through the point faces to burnish the point faces.

    e. Lube the point cams with a small quantity of high quality point cam grease.

  6. Set the point gap to .45 mm + .05mm (.017" + .002")
  7. Remove the timing mark inspection cover held in place with the two (2) 6mm bolts on the left counte rweight cover.
  8. Remove the spark plug from the rotor housing.
  9. Insert the spark plug into the plug cap and lay the spark plug by the timing mark inspection hole.
  10. Turn the ignition key to the "On" position.
  11. Turn the 17mm T-handle clockwise and note at how many degrees BTDC the spark plug fires. Set to 5 (degrees) BTDC.
  12. Adjust the timing by gently loosening the four (4) allen head bolts holding the breaker point housing and rotating the housing CCW to advance the timing and CW to retard the timing.
  13. After setting the timing, tighten the four (4) breaker point housing allen bolts gently and evenly in a criss-cross pattern. This procedure is necessary to prevent breaking the breaker point housing mounting tabs.
  14. Recheck the ignition timing..
  15. Reinstall the nylon point covers and the breaker point housing cover.
  16. Gap the spark plug to .55mm (.022 in.) and reinstall.


  1. Loosen and run all of the throttle cable adjusters all of the way in. (Total of 7 adjusters.)
  2. Loosen the lock nut on throttle grip stop and run the throttle stop adjusting screw out until it no longer affects the throttle grip movement.
  3. Remove the fuel tank after disconnecting the petcock vacuum line, the fuel line and the fuel level switch connector.
  4. Loosen the carburetor air inlet hose clamp, remove the hose from the carburetor intake horn and fold the hose back under the upper frame tube.
  5. Remove the three (3) acorn nuts and the carburetor intake horn.
  6. Remove the 8mm nuts and washers that hold the carburetor to the intake manifold.

    NOTE: The nuts may be removed by using a 12 point, 12mm, box end wrench from the left side or a 3/8" drive 12mm socket, universal, extension, and ratchet from the right side. It is not necessary to remove the fan.

  7. Back the idle speed adjusting screw out all of the way.
  8. Remove the rubber plug in the carb cover.
  9. Turn the carburetor sideways and rest the carburetor stud on the intake manifold stud. This will hold the carburetor while adjustments are being made. Make certain that there is no tension on any of the cables.

    (comment about metering oil line)

  10. With the choke in the "off" position check to make certain that the primary throttle plate is closing completely.

    NOTE: If the adjusters are run all of the way in, the idle speed screw is completely out, and the choke lever is in the "off" position and the primary throttle plate still will not close completely, check the part number printed on the pull cable close to the cable adjuster at the throttle grip. If the cable is stamped 37000 it may be neccesary to remove the throttle grip stopper piece from inside the throttle grip housing to obtain a compeltely closed primary throttle plate. Be sure to reinstall the stopper piece after completing all adjustments.

  11. Install the carburetor angle indocator "C" on the primary throttle plate shaft. (09913-13730)
  12. Install a wire pointer to one of the carb cover screws and set it to 0 (degrees) as shown:

  13. Accelerator Pump Touch Timing Adjustment:

    a. Early Style accelerator pump: This pump can be identified by the right angle bend in the pump arm.

    To adjust this style accelerator pump the excess play must be manually removed from lever to accurately determine when the diaphragm begins to be compressed.

    1) Lightly press down on the accelerator pump arm as shown. Press just hard enough to remove the slack from the linkage.

    2) Slowly twist the throttle until the accelerator pump just begins to move. This should be 28 (degrees).

    NOTE: Be sure that there is fuel in the float bowl and accelerator pump before checking touch timing..

    3) If the lever begins to move either before or after 28 (degrees), adjust the timing by bending the brass-colored tab located beside the carburetor cable pulley on the primary throttle shaft.

    NOTE: Be careful when bending the tab not to warp the arm that the tab is on. Check for free movement of this arm after bending the tab.

    b. New Style Accelerator Pump: Since there should be little or no play in this system follow procedures 14. a. 2) and 14. a. 3).

  14. Fast Idle Adjustment:

    a. Return the throttle grip to the closed position. Check to see that the primary throttle plate closes completely to a fully closed position. On some carburetors it may be neccesary to manually close the throttle plate the final 5 or 10 degrees.

    b. Press the choke lever down to the full "On" position. The primary throttle should open 25.5 (degrees) + 0.75 (degrees). If it opens more or less than this figure adjsut by bending the fast idle rod.

    NOTE: It is neccesary to remove the carburetor cover to do this.

  15. Cable Adjustment:

    (Cable Adjustment is the crucial tuning procedure on the RE5. The port valve must open just as the secondary begins to open, and this is adjusted by comparing the setting on carb tool C with the mark on the port valve. Carb Tool C is available from Rotary Recycle. Misadjustment of this causes the famous horrendous flat spot between the primaries and the secondaries, which occurs just at freeway cruising speeds. )

    a. Turn the throttle grip pull cable adjuster out approximately 1/8" to ¼" and lock it.

    b. Adjusting full open.

    1) Turn the throttle grip full open and check the primary throttle plate angle. The proper angle is 78 (degrees) to 82 (degrees).

    2) If the angle is less than this, turn out the carburetor pull cable adjuster until this figure is reached. Lock the adjuster.

    3) Check to see that the carburetor will still return to the 0 (degree) position.

    c. Remove the port valve cover.

    d. Port Valve Timing

    1) Turn the trottle grip slowly and check when the port valve lever #1 touches port valve lever #2. The correct timing is 35 (degrees).

    2) Turn out the port valve cable adjuster until this figure is reached.

    NOTE: If the port valve opens too soon (approximately 30 degrees) even with the port valve pull cable adjuster run all of the way in, proceed as follows:

    1. Turn the throttle grip until lever #1 just touches lever #2.

    2. Turn out the carburetor pull cable adjustor until the primary throttle plate indicates 35 (degrees).

    3. Lock the port valve pull cable and the carburator pull cable adjustors.

    4. This may prevent the primary throttle cable from closing by 5 (degrees) or so. However, since the primary throttle plate is open approximately 18 (degrees) at a 1200 rpm idle, this will cause no problems.

    e. Turn the throttle grip full open and tur out the oil pump cable adjuster until the mark on th oil pumparm corresponds with the mark on the oil pump body.

    f. Return Cable Adjustment

    1) Depress the choke lever fully to the "On" position.

    2) Run the carburetor return cable adjuster out approximately the same amount as carburetor pull cable adjuster and lock it.

    3) Turn out the throttle grip return cable adjuster until the choke lever just begins to move.

    4) Turn in the throttle grip return cable adjustor until you have about 1mm of play and lock it.

    5) Turn out the port valve return cable adjuster until only a small amount of slack is left in the return cable.

    6) Lock the adjuster.

  16. Reinstall the carburetor fuel tank etc. and recheck the port valve adjustment. Correct if necessary.
  17. Check the port valve cable routing to insure that it does not interfere with secondary throttle plate linkage.
  18. Run in the idle speed screw until the primary throttle plate is open approximately 18 (degrees) with the choke lever in the "Off" position. Remove the carburetor angle indicator "C".
  19. Setting the idle mixture:

    a. Turn in the primary pilot mixture screw in until the needle lightly bottoms. Back the screw out approximately ½ of a turn.

    b. Thoroughly warm up the engine and set the idle to 1200 rpm.

    c. With the bike on the center stand quickly open the throttle grip to bring the rpm’s over 5,000 then quickly close the throttle grip.

    d. If the exhaust has a popping sound or afterfires on deceleration, turn the primary pilot mixture screw out approximately 1/8 of a turn and repeat step c.

    e Continue this process until there is little or no hesitation when the throttle is quickly opened and no popping or afterfiring when the throttle is quickly closed.

    f. Reset the throttle to 1200 rpm if it has changed.

    NOTE: the correct mixture at idle may cause a slight "lope" to the idle but it will cause no problem.

  20. After the final idle adjustments have been made turn the throttle grip until you can feel the primary throttle plate spring tension against the grip.
  21. Turn in the throttle grip stopper uintil it touches the grip.
  22. Back off the throttle grip slightly and lock it with the lock nut.

    NOTE: This remove the slack from the carburetor pull cable that resulted from opening th eprimary throttle plate from 0(degrees) to approximately 18 (degrees) to obtain a 1200 rpm idle.

  23. Insure that there is a small amount of play left in the grip and that the idle will not raise when the handlebars are turned from side to side.


(end of bulletin)