Transmission (Items 1 through 6)
Transmission (Items 7 through 13)
Status for pawl "8"
Copied from the Rotax / Aprilia 655 Engine Manual
Please read the Disclaimer before attempting any work in this FAQ.
20 March 2006
Also check the following FAQs:
The following table(s) and images were recreated from the Rotax / Aprilia 655 Engine manual. The 655 engine is almost the same engine as the Rotax 654 used in the BMW F650 series. One of the biggest differences is the Rotax 655 contains 5 valves, the Rotax 654 engine contains 4 valves. Other than that there are only a few small changes.
| Note: Tables are based on carb models |
|---|
| The tables below are based on a carb bike, and not on the newer FI models. However most of it is still relevant for all models. |
Engine Difficult Or Impossible To Start | |||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Spark plug loose | Tighten spark plug | ||||||||||||||||||||||||||||||||||
| Spark plug fouled or wet | Clean or exchange spark plug | ||||||||||||||||||||||||||||||||||
| Spark plug defective | Renew spark plug | ||||||||||||||||||||||||||||||||||
| Spark plug heat range not correct | Fit spark plug of specified heat range | ||||||||||||||||||||||||||||||||||
| No fuel in carburetor | Check float level | ||||||||||||||||||||||||||||||||||
| Valve clearances too small | Adjust valve clearances | ||||||||||||||||||||||||||||||||||
| Valve timing disadjusted | Adjust position of camshaft sprockets | ||||||||||||||||||||||||||||||||||
| Decompressor blocked | Check easy movement of decompressor, Replace pressure spring | ||||||||||||||||||||||||||||||||||
| Ignition circuit in short-circuit | Check ignition circuit, engine-stop-switch and/or side stand safety switch, replace | ||||||||||||||||||||||||||||||||||
| Electric starter does not spin crankshaft or only by jerks | Check battery, replace | ||||||||||||||||||||||||||||||||||
| Excessive distance between trigger coil and rotor | Adjust distance | ||||||||||||||||||||||||||||||||||
| Ignition coil or ignition cable defective | Exchange | ||||||||||||||||||||||||||||||||||
| Ignition unit defective | Check stator, rotor and electronic box, Exchange defective component | ||||||||||||||||||||||||||||||||||
| Cylinder head gasket defective | Exchange cylinder head gasket | ||||||||||||||||||||||||||||||||||
| Valves and valve guides worn or imperfect valve seat | Exchange valves, valve guides, rework valve seats | ||||||||||||||||||||||||||||||||||
| Piston rings worn | Exchange piston rings | ||||||||||||||||||||||||||||||||||
| Cylinder bore worn | Exchange cylinder | ||||||||||||||||||||||||||||||||||
Engine Does Not Function Well At Idle Speed | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Excessive spark plug electrode gap | Exchange spark plug | ||||||||||||||||||||||||||||||||||
| Valve clearance too small | Adjust valve clearance | ||||||||||||||||||||||||||||||||||
| CO-content too low | Clean carburetor, check carburetor jets, adjust idling | ||||||||||||||||||||||||||||||||||
| Decompressor blocked | Check easy movement of decompressor, replace pressure spring | ||||||||||||||||||||||||||||||||||
| Intake flange not tight | Tighten intake flange, exchange if necessary | ||||||||||||||||||||||||||||||||||
| Ignition unit defective | Check stator, rotor and electronic box, Exchange defective component | ||||||||||||||||||||||||||||||||||
| Valves leaking | Rework valve seats | ||||||||||||||||||||||||||||||||||
Engine Has No Or Insufficient Performance | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Carburetor soiled | Clean jets | ||||||||||||||||||||||||||||||||||
| Air leak / intake flange not tight | Tighten or exchange intake flange | ||||||||||||||||||||||||||||||||||
| Electrode gap of spark plug too small | Exchange spark plug | ||||||||||||||||||||||||||||||||||
| No valve clearance | Adjust valve clearance | ||||||||||||||||||||||||||||||||||
| Decompressor blocked | Check decompressor | ||||||||||||||||||||||||||||||||||
| Too much oil in engine | Drain excessive oil, Check oil pressure retaining valve | ||||||||||||||||||||||||||||||||||
| Valve timing disadjusted | Check position of camshaft sprockets | ||||||||||||||||||||||||||||||||||
| Ignition unit defective | Check stator, rotor and electronic box, Exchange defective component | ||||||||||||||||||||||||||||||||||
| Ignition coil supplies insufficient ignition voltage | Exchange ignition coil | ||||||||||||||||||||||||||||||||||
| Valves leaking | Renew valves, rework valve seats | ||||||||||||||||||||||||||||||||||
| Piston rings worn | Exchange piston rings | ||||||||||||||||||||||||||||||||||
| Cylinder bore worn | Exchange cylinder | ||||||||||||||||||||||||||||||||||
Engine Is Pinking At Full Load | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Fuel of too low octane number | Use fuel of specified octane number | ||||||||||||||||||||||||||||||||||
| Spark plug of wrong heat range | Use spark plug of specified heat range | ||||||||||||||||||||||||||||||||||
| Air intake system leaking | Eliminate leak | ||||||||||||||||||||||||||||||||||
| Ignition unit defective | Check stator, rotor and electronic box, Exchange defective component | ||||||||||||||||||||||||||||||||||
Engine Overheats | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Not enough coolant in cooling system, system leaking | Refill coolant, check system under pressure | ||||||||||||||||||||||||||||||||||
| Not enough oil in the engine | Refill oil | ||||||||||||||||||||||||||||||||||
| Radiator obstructed | Clean radiator outside and inside | ||||||||||||||||||||||||||||||||||
| Thermostat defective | Replace thermostat | ||||||||||||||||||||||||||||||||||
| Water pump or drive gear defective | Repair water pump, or check and renew water pump drive | ||||||||||||||||||||||||||||||||||
| Oil pumps or oil pump drive defective, oil circuit blocked | Exchange oil pumps or oil pump gears, clean circuit | ||||||||||||||||||||||||||||||||||
Engine Produces Excessive Exhaust Fumes ('Blue Smoke') | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Too much oil in the engine | Drain excessive motor oil, check oil pressure retaining valve | ||||||||||||||||||||||||||||||||||
| Cylinder head gasket defective | Replace cylinder head gasket | ||||||||||||||||||||||||||||||||||
| Valve stem seals worn | Renew valve stem seals | ||||||||||||||||||||||||||||||||||
| Piston rings worn | Replace piston rings | ||||||||||||||||||||||||||||||||||
| Cylinder bore worn | Replace cylinder | ||||||||||||||||||||||||||||||||||
Engine Vibrates | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Engine fixation has loosened | Fasten engine fixation | ||||||||||||||||||||||||||||||||||
| A bearing or bearing seat is worn | Replace bearing or worn component | ||||||||||||||||||||||||||||||||||
Oil Pressure Lamp Lights Up | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Not enough oil in engine | Refill motor oil | ||||||||||||||||||||||||||||||||||
| Oil pressure switch defective | Replace oil pressure switch | ||||||||||||||||||||||||||||||||||
| Oil pressure regulating valve blocked or defective (valve remains open) | Clean or replace oil pressure regulating valve | ||||||||||||||||||||||||||||||||||
| Oil pump drive defective | Replace oil pump drive | ||||||||||||||||||||||||||||||||||
| Oil pump(s) worn | Replace oil pump(s) | ||||||||||||||||||||||||||||||||||
Engine Produces Excessive Oil Pressure | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Oil pressure regulating valve defective (valve remains close) | Replace oil pressure regulating valve | ||||||||||||||||||||||||||||||||||
| Oil circuit blocked | Clean oil ducts | ||||||||||||||||||||||||||||||||||
Engine Operates Excessively Noisy | |||||||||||||||||||||||||||||||||||
| Possible causes | Remedy | ||||||||||||||||||||||||||||||||||
| Noise seems to come from the valve train | |||||||||||||||||||||||||||||||||||
| Excessive valve clearance | Adjust valve clearance | ||||||||||||||||||||||||||||||||||
| Decompressor is instable | Replace pressure spring of decompressor centrifugal weight | ||||||||||||||||||||||||||||||||||
| Exhaust camshaft has axial play | Adjust axial play of exhast camshaft | ||||||||||||||||||||||||||||||||||
| Camshaft or bearing supports of camshaft worn | Replace camshaft or cylinder head | ||||||||||||||||||||||||||||||||||
| Camshaft drive is worn or drive sprockets loose | Tighten or replace camshaft sprockets | ||||||||||||||||||||||||||||||||||
| Rocker arm roller or adjustment screw defective | Replace parts | ||||||||||||||||||||||||||||||||||
| Noise seems to come from the camshaft chain | |||||||||||||||||||||||||||||||||||
| Chain tensioner does not work | Replace adjustment spring on chain tensioner, readjust | ||||||||||||||||||||||||||||||||||
| Camshaft chain or chain guides are worn | Replace camshaft chain or chain guides | ||||||||||||||||||||||||||||||||||
Noise seems to come from the piston
| Piston or cylinder bore worn
| Replace piston or cylinder
| Piston or piston pin worn
| Replace piston or piston pin
| Piston rings broken or ring grooves worn
| Replace piston rings or complete piston
| Noise seems to come from the crankshaft or balance shaft
| Bearing of crankshaft or balance shaft worn
| Exchange bearing of balance shaft or bearing halves of crankcase | or replace balance- or crankshaft Sprag clutch worn
| Replace sprag clutch
| Axial play of crankshaft or balance shaft excessive
| Adjust axial play with shims
| Split balance drive gear defective
| Replace springs of split geats, eventually new set of gears
| Conrod bearing or crankshaft is worn
| Replace complete crankshaft
| Noise seems to come from the clutch
| Friction clutch disks (hammer heads) worn
| Replace clutch disks
| Excessive or insufficient backlash on teeth of primary drive
| Replace primary drive
| Clutch drum, clutch hum or pressure plate is worn
| Replace worn components
| Clutch drum bearings worn
| Replace bearings or primary drive
| Noise seems to come from the gearbox
| Tooth flanks of gearbox gears worn
| Check gears and gear shafts, replace if necessary
| Bearings are worn
| Replace bearings
| | ||||
|
Transmission (Items 1 through 6) |
Transmission (Items 7 through 13) |
Status for pawl "8" |
Gears Jump Out At Start Or At Abrupt Acceleration | |
|---|---|
| Possible causes | Remedy |
| Gearshifting action incomplete | Always actuate gearshift lever till stop |
| Gearshift lever incorrectly adjusted | Correct position of gearshift lever |
| Fastening screw of gearshift lever loose | Tighten gearshift lever with specified torque |
| Gearshift lever bent or touching motorcycle frame or crankcase | Replace gearshift lever |
| (Perform function check as listed above) Function check with engine removed and disassembled: | |
| Index spring "1" not correctly engaged on index lever "2" | Engage index spring |
| Preload of index spring "1" not sufficient. Check: The index lever "2" must be able to be lifted only with a certain force "K" from the index shem "3". When turning shaft drum "4" the index spring must press the index lever into the respective "valley" on the index shim "3". | Replace index spring |
| Index lever "2" is not moving easily. Check: Check for easy spring movement , with index spring removed. | Replace index lever |
| Roller "5" of index lever "2" does not slide on index shim "3". Check: Index lever is bent or rivet "6" of roller is loose. | Replace index lever |
| Position of index shim "3" in relation to shift drum "4" is
incorrect Check: Check complete engagement of dogs in the gears of the speed selected. | |
Gear shifting is difficult or jerky | |
| Possible causes | Remedy |
| Gearshift shaft "7" bent or damaged. Return to "neutral" position
does not function correctly. Check: Shift gears, with clutch cover removed. | Disassemble engine and check gearshift shaft with a straightedge (0.3mm deflection admissible). If excessive deflection, replace gearshift shaft. |
| Function of pawl "8" is not perfect. (Perform function check as listed above). Function check with engine removed and disassembled: | |
| Rivet connection "9" of shift lever "10" and pawl "8" not easily
movable Check: Pawl "8" must engage and disengage in pegs "13" when turning shift drum "4". Check for easy movement, with pawl spring "11" removed. | Exchange gearshift shaft with pawl assembly |
| Hook "11" of pawl spring scours on leg of hairpin spring "12" when
shifting up. Check: Check for sufficient clearance between the ends of pawl spring and hairpin spring | Bend end of pawl spring "11" adequately or replace pawl spring |
| Pawl "8" scours on shift drum "4" or on index lever "2". Check: Check for scouring traces and easy movement of pawl. check for correct fit of pawl spring. | Replace pawl spring and/or gearshift shaft complete pawl |
| Pawl "8" is hooked in one peg "13" of shift drum, with index lever
engaged. Check With index lever engaged, lift pawl "8" from shift drum by hand. If the pawl is hooked in a peg, with index lever engaged in the index shim, check hairpin spring "12" as follows: The two legs of the hairpin spring "12" must be perfectly parallel and lie flat around crankcase boss "14". Only a minimum play between the legs of hairpin spring and rivet "9" on lever "10" is admissible. | Bend ends of hairpin spring "12" until with index lever "2"
engaged the status "B" is achieved and pawl "8" can be lift from shift
drum without jerks. Attention: When fitting a new hairpin spring, also make this check, adjust spring by bending, if necessary. |
| Before engine installation in frame check function and especially "clicking" when index lever "2" and pawl "8" engage! | |
Gears Can Be Shifted On Warm Engine Only With Increased Force | |
| Possible causes | Remedy |
| Clutch does not disengage | Adjust clutch free play of clutch cable correctly |
| Clutch does not disengage. Due to expeansion and wear of the
clutch cable the clutch freeplay is excessive. Check: Check both ends of clutch cable for perfect condition | Renew clutch cable |
| Clutch does not disengage - wrong position of clutch release lever | Fit clutch release lever correctly. |
| Clutch does not disengage - clutch release lever not tightened enough | Fit clutch release lever correctly and fasten tightening screw at the specified torque |
| Clutch does not disengage exactly - clutch disks excessively warped | Check warping with straightedge, replace clutch disks if necessary |
| Clutch does not disengage - clutch release lever defective or cracked | Replace clutch release lever |
| Clutch does not disengage exactly Check: The outer offset disk should only have a minimum of freeplay, however not squeeze in clutch drum. | Change the outer friction clutch disk against an other friction disk of the disk package which does not squeeze |
| Gearshift shaft bent. Check: Only possible on engine disassembled - see above checking and remedy hints | Replace gearshift shaft and check gear shifting |
Gears Can Be Shifted Only Noisily | |
| Possible causes | Remedy |
| Final drive chain tension too loose - whip effect when shifting gears up and down | Tension final drive chain as indicated and check clutch adjustment |
| Clutch does not disengage | See hints above regarding "Clutch does not disengage" |
Clutch Slips | |
| Possible causes | Remedy |
| Insufficient clutch freeplay | Adjust clutch freeplay |
| Fatigue of clutch springs | Replace clutch springs |
| Friction clutch disks worn | Exchange friction clutch disks |
| Engine oil with "Friction Modifiers" | Exchange engine oil, wait for further 500 kms |
Clutch disengages unsatisfactorily | |
| Possible causes | Remedy |
| Engine oil of wrong oil specification used | Use engine oil specified |
Clutch "Drags" at Engagement | |
| Possible causes | Remedy |
| Friction and steal clutch disks warped or warn | Renew disks |
| Guide slots for clutch disks in clutch drum are worn | Replace complete primary drive |
| Guide slots for the steel disks in clutch hub are worn | Replace clutch hub |
The ignition unit is a breakerless capacitor discharge unit with electronically variable ignition timing and a 3-phase AC generator (12V 280W). It cannot be adjusted and is maintenance free. [Ed note: The AC generator was increased to 400W on later models].
| Never disconnect electrical connections while the engine is running |
|---|
Before any repair, remove ignition key and disconnect battery (first minus pole). Caution: high voltage on ignition unit! Attention: The amplifier box must not be exposed to mechanical impacts. For removal of rotor use puller (976 235) and protection mushroom (277 135). |
| Symbol | Color |
|---|---|
| GW | Green - white stripe |
| LW | Blue - yellow stripe |
| Y | Yellow |
| W | White |
| B | Black |
| R | Red |
| G | Green |
| L | Blue |
| O | Orange |
If the ignition unit does not supply an ignition spark or if it is suspected there may be an ignition problem, check the following parts in the sequence indicated, or determine the function by exchange of parts:
Note: Before checking, disconnect plug connections. Measure the resistance between 2 measuring points (cables), adjusting the instrument to the required measuring range and adjust the Zero point.
| Measuring points | Resistance (at 20C) | ||
|---|---|---|---|
| AC generator | Coil exit | Y - Y | 0.2 - 0.5 ohms |
| Sensor | GW - LW | 190 - 300 ohms | |
| Ignition coil | Primary winding | terminal - core | 0.2 - 0.5 ohms |
| Secondary winding | high tension wire - core | 6 - 13 k ohms | |
| Spark plug connector | Connection for ignition cable - Connection for spark plug | 0.8 - 1.4 k ohms | |
Note: For checking of electronic box set measuring range of 1k ohm to 10k ohm on the instrument. Also at each measurment take care of the polarity of the cables of the instrument. If one or several values do not correspond with the values indicated, the defective part of the ignition unit must be replaced.
| Electronic Box ND 071000-0790 | - instrument cable (black) | ||||||
|---|---|---|---|---|---|---|---|
| G | W | O | R | B | L | ||
| + instrument cable (red) | G | o | o | o | o | o | |
| W | o | o | o | o | o | ||
| O | x | > | > | x | x | ||
| R | o | o | o | o | o | ||
| B | o | o | o | o | o | ||
| L | o | o | o | o | o | ||
o = passage (instrument dial moves, measuring value of no
importance)
x = no passage (instrument dial does not move)
> = instrument dial may move than returns to infinate