Haynes Yamaha Xv V Twins Manual

							
3B-16 
Chapter 3 Part B Fuel and exhaust systems (XV700-1100 models)

12.2 Fuel pump circuit

1 Fuel pump controller

2 Fuel pump

3 Fuel reserve switch (Res position)

4 Fuel reserve switch (On position)

5 Igniter unit

6 Fuel warning light 
7 Fuel sender (Full position)

8 Fuel sender (Empty position)

9 Engine kill switch

10 Ignition (main key) switch

11 To main fuse and battery

switched on (with the fuel warning light on or off). It should shut off

once the carburetor float chambers are full, then run again once the

engine is started,

2 The fuel pump circuit consists of the pump, the pump controller,

the igniter unit (which controls the fuel pump as well as ignition timing),

the engine kill switch, the ignition switch, the main and ignition fuses,

the battery and related wiring (see illustration).

3 Lift or remove the seat.

4 Check the battery condition and charge (see Chapter 1 and

Chapter 8).

5 Check the main and ignition fuses, the ignition switch and the

engine kill switch (see Chapter 8). Replace them if theyre defective,

then try the fuel pump again.

Pump wont run after engine is started

6 If the pump wont run while the engine is running, check battery

voltage to the pump. Disconnect the fuel pump electrical connector

and connect a 20-volt DC voltmeter between the blue/black wire

terminal in the harness and a good grounding/earthing point (bare

metal on the engine).

7 Turn the ignition switch to On and the engine kill switch to Run,

then push the Start switch. The voltmeter should indicate more than 11

volts. If the reading is more than 11 volts, test the fuel pump (see Step

24 below).

8 If the reading is less than 11 volts, test the output voltage of the

igniters orange lead. To do this, check the spark output of the rear

cylinder (see Chapter 4). If the spark will jump the specified gap, you 
can assume that the igniter output voltage is within specifications. Go

to Step 10 below.

9 If the spark wont jump the specified gap, measure the igniter

input voltage at the red wire (see illustration 12.2).

a) If its at least 12 volts, the igniter may be defective. Check the

ignition system as described in Chapter 4.

b) If theres no voltage at the red wire, check the engine kill switch,

ignition main key switch and the main fuse. Check the wiring in the

fuel pump circuit for breaks or bad connections. Be sure to check

the battery terminal connections and the battery ground/earth

cable connection to the motorcycle.

10 Make sure the fuel pump controller ground/earth wire is clean and

tight. If it is, test the fuel pump controller (see Step 24 below).

Fuel pump doesnt run for five seconds when

ignition is switched on

11 With the fuel reserve switch set to Res and the kill switch in the

On position, switch on the ignition. If the fuel level in the carburetors is

low, the pump should run for five seconds. If it doesnt, perform the

following steps.

12 Place the ignition switch, kill switch and fuel reserve switch in the

On position, but dont start the engine.

13 Check for voltage at the fuel pump (see Step 6 above).

a) If its more than 11 volts, go to Step 14.

b) If its less than 11 volts, go to Step 17.

14 Turn the fuel reserve switch to the Res position and recheck 
						

							
Chapter 3 Part B Fuel and exhaust systems (XV700-1100 models) 
3B-17

12.27a Fuel pump controller terminal identification

voltage.

a) If its still more than 11 volts, test the fuel pump (see Step 24

below).

b) If its less than 11 volts, go to Step 15.

15 Connect a 0-20 volt voltmeter between the red/green wire at the

fuel pump controller and a good ground/earth connection (bare metal

on the motorcycle).

a) If theres no voltage, test the reserve switch (see Chapter 8).

b) If the reading is 12 volts, go to Step 16.

16 Make sure the fuel pump controller ground/earth wire (black) is

clean and tightly connected. If this doesnt solve the problem, test the

fuel pump controller (see Step 25 below).

17 If voltage at the fuel pump was less than 11 volts in Step 14,

Connect the positive lead of a 0-20 volt voltmeter to the pump

controller red/white wire and the negative lead to ground/earth.

a) If theres no voltage, check the ignition switch, kill switch, main

fuse and battery (see Chapter 8).

b) If the reading is 12 volts, make sure the fuel pump controller

ground/earth wire (black) is clean and tightly connected. If this

doesnt solve the problem, test the fuel pump controller (see Step

25 below).

Fuel pump doesnt stop with warning light on

18 The fuel pump should stop running within 30 seconds if the fuel

warning light comes on with the engine running. If it doesnt, perform

Steps 19 through 23 below.

19 Disconnect the fuel pump electrical connector and connect a 20-

volt DC voltmeter between the blue/black wire terminal in the harness

and a good grounding/earthing point (bare metal on the engine) (see

illustration 12.2).

20 Locate the green wire in the fuel sender connector.

21 Start the engine. Disconnect the green wire and note the reading

on the voltmeter 30 seconds later.

a) If theres no voltage, check the fuel pump circuit wiring for breaks

or bad connections. Repair as necessary.

b) If theres more than 11 volts, go to Step 22.

22 Test the fuel sender (see below).

a) If the resistance is not within the range listed in this Chapters

Specifications, replace the sender.

b) If the sender is good, go to Step 23.

23 Make sure the fuel pump controller ground/earth wire is clean and

tightly connected. Repair as necessary. If this doesnt solve the

problem, test the fuel pump controller (see below).

Fuel pump test

24 Disconnect the wiring connector from the fuel pump. Connect the 
12.27b Connect an ohmmeter between the indicated terminal

pairs and note the readings

*Wait a few seconds after connecting the ohmmeter

to take this reading.

13.1 The fuel pump is located under this cover

pump directly to the battery with two lengths of wire (positive to

blue/black; negative to black). If the pump doesnt run, replace it.

Fuel pump controller test

Refer to illustrations 12.27a and 12.27b

25 Remove the seat (see Chapter 7).

26 Unplug the fuel pump controller and remove it.

27 Connect an ohmmeter between the controller terminals in turn

and measure the resistance (see illustrations). If the resistance is not

as specified, replace the controller.

Fuel sender test

28 Remove the fuel tank (see Section 2).

29 Remove the screws and detach the sender from the tank.

30 Connect an ohmmeter to the terminals of the sender harness.

Raise and lower the sender float and compare the resistance readings

at various heights to the values listed in this Chapters Specifications. If

the readings are not as specified, replace the sender. 
						

							
3B-18

Chapter 3 Part B Fuel and exhaust systems (XV700-1100 models)

13.2 Fuel pump hoses (XV1000

and 1100 models)

1 Fuel pump

2 Hose clamps

3 Outlet hose

4 Inlet hose

13 Fuel pump - replacement

Refer to illustrations 13.1 and 13.2

1 Remove the cover from the fuel pump (see illustration).

2 Loosen the fuel line clamps and push the ends of the fuel lines off

the pump fittings (see illustration).

3 Disconnect the pump electrical connector. Remove the mounting

bolts and take the pump out.

4 Installation is the reverse of the removal steps.

14 Mixture control valve (all 1981 through 1983 models and

TR1; 1984 and 1985 XV700) - testing and replacement

Testing

Refer to illustrations 14.1, 14.4a and 14.4b

1 If youre working on a 1981 through 1983 model, unclip the

plastic cowl for access to the mixture control valve (see illustration).

14.4a Mixture control valve hose routing

(1981 through 1983 models) 
14.1 Remove the plastic cowl for access to the

mixture control valve

14.4b Mixture control valve hose routing (1984 through

1987 XV700 models)

1 Carburetor intake joint

2 Mixture control valve 
3 To fuel tap 
						

							
Chapter 3 Part B Fuel and exhaust systems (XV700-1100 models)

3B-19

14.5 Unclip the mixture control valve and disconnect its hoses

2 If youre working on a 1984 or 1985 XV700, remove the case

cover (on the left side of the motorcycle between the cylinders).

3 Start the engine and let it idle. Hold a strip of paper next to the

inlet side of the valve.

4 Raise engine speed to 5,000 rpm. The paper should be pulled

toward the valve by air flow. If it isnt, check the vacuum hoses to the

valve (see illustrations). If theyre in good condition and properly

connected, replace the valve.

Replacement

Refer to illustration 14.5

5 Detach the valve from its clip (see illustration). Label and

disconnect the hoses.

6 Attach the tioses to the valve and secure it in its clip.

15 Air induction system (XV1000, XV1100 and 1988 and

later XV750) - inspection and component replacement

Refer to illustrations 15.2a, 15.2b and 15.2c

1 The air induction system uses exhaust gas pulses to suck fresh

air into the exhaust ports, where it mixes with hot combustion gases.

The additional oxygen provided by the fresh air allows combustion to

continue for a longer time, reducing unburned hydrocarbons in the

exhaust. Reed valves allow the flow of air into the ports and prevent 
15.2a Air induction system hose routing (1984 and

1985 XV1000 models)

1 Carburetor intake joint

2 Air cutoff valve

3 Mixture control valve

4 Air filter case

5 To pressure sensor

6 Arrow mark (toward pressure sensor)

exhaust gas from flowing into the system. The air cut valve shuts off

the flow of air into the system during deceleration to prevent

backfiring. The system uses a mixture control valve similar to that

described in Section 14.

2 Check the hoses for loose connections, damage and deterio-

ration (see illustrations). Tighten or replace loose or damaged hoses.

15.2b Air induction system hose

routing (1986 and later

XV1100 models)

1 Face clamp ends downward

2 Face clamp ends outward

3 Face clamp ends inward

4 Face clamp ends toward front of

motorcycle

5 To pressure seriSor

6 To coasting erlricher (1986 and

1987 models)

7 Face clamp ends downward

8 Face arrow mark toward

pressure senso.r

9 Place hose bend projection in

square hole

10 Face white paint mark toward air

cutoff valve

11 Face arrow mark toward air cut

valve 
						

							
3B-20 
Chapter 3 Part B Fuel and exhaust systems (XV700-1100 models)

15.2c Air induction system hose routing

(1988 and later XV750 models)

1 Face clamp ends inward

2 To fuel tap

3 Face clamp ends downward

4 Place hose bend projection

in square hole

5 Face white paint mark toward

air cut valve

6 Face arrow mark toward air cut

valve

3 To replace system components, remove the left side cover.

Disconnect the hoses, remove the mounting screws and take the

assembly off the motorcycle.

4 To test the mixture control valve, refer to Section 14.

5 To inspect the reed valve, remove the Allen bolts and

disassemble the reed valve case. Measure the height of the reed

valves from the base. If its not as listed in this Chapters Specifi-

cations, replace the reed valve. Replace the reed valve assembly

gasket if its brittle, cracked or torn.

6 Installation is the reverse of the removal steps. 
16 Evaporation control system (California models) -

inspection and canister replacement

Refer to illustration 16.1

1 The evaporation control system used on California models

prevents fuel vapor 
						

							
4A-1

Chapter 4 Part A

Ignition system (XV535 models)

Contents

Section

General information 1

Igniter - check, removal and installation 5

Ignition coils - check, removal and installation 3 
Section

Ignition system - check 2

Pick-up coil - check, removal and installation 4

Spark plugs - replacement See Chapter 1

Specifications

Ignition coil

1987 through 1993 US models

Primary resistance 3.8 to 4.6 ohms at 20-degrees C (68-degrees F)

Secondary resistance 10,600 to 16,800 ohms at 20-degrees C (68-degrees F)

1994 US models

Primary resistance3.6 to 4.8 ohms at 20-degrees C (68-degrees F)

Secondary resistance 11,200 to 15,200 ohms at 20-degrees C (68-degrees F)

1988 UK models

Primary resistance 3.8 to 4.6 ohms at 20-degrees C (68-degrees F)

Secondary resistance 10,600 to 15,800 ohms at 20-degrees C (68-degrees F)

1989 through 1993 UK models

Primary resistance 3.8 to 4.6 ohms at 20-degrees C (68-degrees F)

Secondary resistance 12,000 to 14,500 ohms at 20-degrees C (68-degrees F)

1994 UK models

Primary resistance 3.8 to 4.6 ohms at 20-degrees C (68-degrees F)

Secondary resistance 10,100 to 15,800 ohms at 20-degrees C (68-degrees F)

Spark plug cap resistance (UK models) 10,000 ohms at 20-degrees C (68-degrees F)

Spark plug arcing distance 6 mm (1/4 inch)

Pick-up coil resistance

1987 through 1993 140 to 170 ohms at 20-degrees C (68-degrees F)

1994 182 to 222 ohms at-degrees C (68-degrees F)

Ignition timing Not adjustable 
						

							
4A-2 
Chapter 4 Part A Ignition system (XV535 models)

1 General information

This motorcycle is equipped with a battery operated, fully transis-

torized, breakerless ignition system. The system consists of the

following components:

Pick-up coil

Igniter unit

Battery and fuse

Ignition coils

Spark plugs

Ignition (main), engine kill (stop), sidestand and neutral switches

Primary and secondary (HI) circuit wiring

The transistorized ignition system functions on the same principle

as a breaker point DC ignition system with the pick-up coil and igniter

performing the tasks previously associated with the breaker points and

mechanical advance system. As a result, adjustment and maintenance

of ignition components is eliminated (with the exception of spark plug

replacement). Models through 1993 use two pick-up coils; 1994 and

later models use a single pick-up coil.

Because of their nature, the individual ignition system

components can be checked but not repaired. If ignition system

troubles occur, and the faulty component can be isolated, the only

cure for the problem is to replace the part with a new one. Keep in

mind that most electrical parts, once purchased, cant be returned. To

avoid unnecessary expense, make very sure the faulty component has

been positively identified before buying a replacement part.

2 Ignition system - check

Refer to illustration 2.14

Warning: Because of the very high voltage generated by the ignition

system, extreme care should be taken when these checks are

performed.

1 If the ignition system is the suspected cause of poor engine

performance or failure to start, a number of checks can be made to

isolate the problem.

2 Make sure the engine kill switch is in the Run position. .

Engine will not start

3 Disconnect one of the spark plug wires, connect the wire to a

spare spark plug and lay the plug on the engine with the threads

contacting the engine. If necessary, hold the spark plug with an

insulated tool. Crank the engine over and make sure a well-defined,

blue spark occurs between the spark plug electrodes. Warning: Dont

remove one of the spark plugs from the engine- to perform this check -

atomized fuel being pumped out of the open spark plug hole could

ignite, causing severe injury!

4 If no spark occurs, the following checks should be made:

5 Unscrew a spark plug cap from a plug wire and lay the plug wire

on the cylinder head. Crank the engine over and check for spark again.

If a strong blue spark occurs between the end of the wire and the

engine, the plug cap or plug is faulty. If not, go to the next steps.

6 Make sure all electrical connectors are clean and tight. Check all

wires for shorts, opens and correct installation.

7 Check the battery voltage with a voltmeter and - on models

equipped with batteries having removable filler caps - check the

specific gravity with a hydrometer (see Chapter 1). If the voltage is less

than 12-volts or if the specific gravity is low, recharge the battery.

8 Check the ignition fuse and the fuse connections. If the fuse is

blown, replace it with a new one; if the connections are loose or

corroded, clean or repair them.

9 Refer to Chapter 8 and check the ignition switch, engine kill

switch, neutral switch and sidestand switch.

10 Refer to Section 3 and check the ignition coil primary and

secondary resistance.

11 Refer to Section 4 and check the pick-up coil resistance. 
2.14 A simple spark gap testing fixture can be made from a

block of wood, a large alligator clip, two nails, a

screw and a piece of wire

12 If the preceding checks produce positive results but there is still

no spark at the plug, remove the igniter and have it checked by a

Yamaha dealer service department or other repair shop equipped with

the special tester required.

Engine starts but misfires

13 If the engine starts but misfires, make the following checks before

deciding that the ignition system is at fault.

14 The ignition system must be able to produce a spark across a six

millimeter (1/4-inch) gap (minimum). A simple test fixture (see

illustration) can be constructed to make sure the minimum spark gap

can be jumped. Make sure the fixture electrodes are positioned six

millimeters apart.

15 Connect one of the spark plug wires to the protruding test fixture

electrode, then attach the fixtures alligator clip to a good engine

ground/earth.

16 Crank the engine over (it may start and run on the remaining

cylinder) and see if well-defined, blue sparks occur between the test

fixture electrodes. If the minimum spark gap test is positive, the

ignition coil for that cylinder is functioning properly. Repeat the check

on the spark plug wire that is connected to the other coil. If the spark

will not jump the gap during either test, or if it is weak (orange colored),

refer to steps 5 through 11 of this.Section and perform the component

checks described.

3 Ignition coils - check, removal and installation

Check

Refer to illustrations 3.4 and 3.6

1 In order to determine conclusively that the ignition coils are

defective, they should be tested by an authorized Yamaha dealer

service department which is equipped with the special electrical tester

required for this check.

2 However, the coils can be checked visually (for cracks and other

damage) and the primary and secondary coil resistances can be

measured with an ohmmeter. If the coils are undamaged, and if the

resistances are as specified, they are probably capable of proper

operation.

3 To check the coils for physical damage, they must be removed (see

Step 9). To check the resistances, simply remove the ignition coil cover

from the forward side of the front cylinders mounting bracket, unplug

the primary circuit electrical connectors from the coil(s) and remove the

spark plug wire from the plug that is connected to the coil being 
						

							
Chapter 4 Part A Ignition system (XV535 models)

4A-3

3.4 To test the coil primary resistance, connect the ohmmeter

leads between the primary terminals in the coil connector 
3.6 To test the coil secondary resistance, connect the ohmmeter

between the spark plug wire (HT) terminal and

one of the primary terminals

checked. Mark the locations of all wires before disconnecting them.

4 To check the coil primary resistance, attach one ohmmeter lead

to one of the primary terminals and the other ohmmeter lead to the

other primary terminal (see illustration).

5 Place the ohmmeter selector switch in the Rx1 position and

compare the measured resistance to the value listed in this Chapters

Specifications.

6 If the coil primary resistance is as specified, check the coil

secondary resistance by disconnecting either meter lead from the

primary terminal connector and attaching it to the spark plug wire (HT)

terminal (see illustration).

7 Place the ohmmeter selector switch in the Rx1000 position and

compare the measured resistance to the values listed in this Chapters

Specifications.

8 If the resistances are not as specified, the coil is probably

defective and should be replaced with a new one.

Removal and installation

Refer to illustrations 3.9 and 3.10

9 To remove the coils, refer to Chapter 4 and remove the upper fuel 
tank (later models) or Chapter 7 to remove the top cover (early

models), then disconnect the spark plug wires from the plugs. After

labeling them with tape to aid in reinstallation, unplug the coil primary

circuit electrical connectors (see illustration).

10 Unbolt the cp.il bracket and remove it from the frame (see

illustration). Remove the coil mounting bolts and take the coil(s) off

the bracket.

11 Installation is the reverse of removal. Make sure the primary circuit

electrical connectors are attached to the proper terminals; use their wire

colors for identification (see the Wiring diagrams at the end of the book).

4 Pick-up coil - check, removal and installation

Check

Refer to illustrations 4.1a and 4.1b

1 Remove the right front side cover (see Chapter 7). On 1987

through 1993 models, locate the four-pin pick-up coil wiring connector

3.9 Disconnect the coil primary connectors (arrows)

3.10 Unbolt the coil bracket and remove it together with the coils 
						

							
4A-4

Chapter 4 Part A Ignition system (XV535 models)

4.1a The pick-up coil connector on 1987 through 1993 models is

on the underside of the igniter at the rear (arrow);

if necessary, remove the igniter for access

at the igniter (see illustration). On 1994 and later models, follow the

gray and black wires from the igniter to the two-pin connector in the

wiring harness (see illustration). Disconnect the connector. Note: On

1987 through 1993 models, it may be easier to remove the igniter for

access to the connector (see Section 5).

2 Make the test on the pick-up coil side of the connector. Probe the

terminals in the connector with an ohmmeter and compare the

resistance reading with the value listed in this Chapters Specifications.

On 1987 through 1993 models two tests are required: brown to green

and red to blue.

3 If the pick-up coil(s) fail the above test, it must be replaced.

Removal

Refer to illustration 4.5

4 Remove the alternator cover from the left side of the engine (see

Chapter 8).

5 Unscrew the mounting screws and remove the pick-up coil(s)

(see illustration).

Installation

6 Installation is the reverse of the removal steps.

5 Igniter - check, removal and installation

Check

1 The igniter is checked by process of elimination (when all other

possible causes have been checked and eliminated, the igniter is at

fault). Because the igniter is expensive and cant be returned once

purchased, consider having a Yamaha dealer test the ignition system

before you buy a new igniter.

Removal and installation

Refer to illustration 5.3

2 Remove the right front side cover and the bracket inside it (see

Chapter 7).

3 Slide the electrical component board off its mounting posts to

detach it from the bracket. Turn the component board around so the

igniter mounting screws are visible. Unplug the electrical connector,

remove the mounting screws and take the igniter out (see illustration).

4 Installation is the reverse of the removal steps. 
4.1b The pick-up coil connector on 1994 and later models is in

the wiring harness; it can be identified by its wire colors

1 Gray

2 Black

4.5 Pick-up coil mounting screws (arrows) - two-coil type shown

5.3 Unplug the connectors and remove the mounting screws

(arrows) to detach the igniter from the component board 
						

							
4B-1

Chapter 4 Part B

Ignition system (XV700-1100 models)

Contents

Sect/on

General information 1

Igniter - check, removal and installation 5

Ignition coils - check, removal and installation 3

Ignition system - check 2 
Section

Pick-up coils - check, removal and installation 4

Spark plugs - replacement See Chapter 1

Pressure sensor (1984 and later XV1000 and XV1100 models) -

testing, removal and installation 6

Specifications

Ignition coil

1981 through 1983 models

Primary resistance 2.7 ohms +/-15% at 20-degrees C (68-degrees F)

Secondary resistance 8500 ohms +/-15% at 20-degrees C (68-degrees F)

1984-on models

Primary resistance 3.57 to 4.83 ohms at 20-degrees C (68-degrees F)

Secondary resistance 11,220 to 15,180 ohms at 20-degrees C (68-degrees F)

Spark plug cap resistance

All except TR1 models 5000 ohms at 20-degrees C (68-degrees F)

TR1 models 7000 ohms at 20-degrees C (68-degrees F)

Spark plug arcing distance 6 mm (1/4 inch)

Pick-up coil resistance

Dual pick-up coils 124 to 186 ohms at 20-degrees C (68-degrees F)

Single pick-up coil..... 182 to 222 ohms at 20-degrees C (68-degrees F)

Pressure sensor output voltage 3.00 +/- 0.05 volts

Ignition timing
 Not adjustable