1984-2007 Honda CR80/CR85/CR125/CR250 Fuel System & Service Manual

CR80R, CR85R, CR125R, CR250R DOWNLOAD!


Honda Fuel System & Service Manual Download
Always refer to a service manual before attempting to do any work on your motorcycle, important data including step-by-step procedures, diagrams, pictures, illistrations, specifications cleaning & maintenance information will help you care for and lower the chances of premature parts failurer. Below is a great reference source available for instant download straight to your computer in just seconds.
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All manuals are simple to use pdf downloads and are delivered straight to your computer in just seconds. Not sure what a pdf is? Here is a sample of what a  Service Manual looks like (sample is restricted to one page only).
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Service Manuals Downloads
 
HONDA CR125/CR125R
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HONDA CR250/250R
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HONDA CR80/85R
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MODEL/YEAR APPLICATION:

Honda CR125R, CR125-R, CR-125-R, CR125 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 & 2007 models.

Honda CR250R, CR250, CR-250R, CR250-R 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06 & 07 year CR250R models.

Honda  CR80R, CR85R, CR80, CR85, CR-80-R, CR-85-R 1984, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06 & 07 year CR-80/85-R models.


This CR80/85/125/250-R fuel system guide describes the Honda CR80R, CR85R, CR125R & CR250R procedures as general procedures for Honda CR80R / CR85R / CR125R & CR250R motorcycles. It is only recommended to follow the fuel system guide in the reference guide links listed above as they contain the same information mechanics and technicians use to service your bike.

Important information contained in this page like special notes, tips, proper procedures, complete specifications, torque specs and recommendations must be followed in the reference links to ensure that the task is performed in the proper flow and to manufacture specification recommendations.

 



Common Honda Searches: 

TROUBLESHOOTING

FUEL STARVATION/LEAN MIXTURE

 

Restricted tank vent, or routed Fuel lines or fuel valve restricted Fuel filter plugged Carburetor vent line(s) restricted Plugged or restricted inlet needle Clogged jets or passages Float stuck, holding inlet needle Float level too low Fuel pump inoperative Air leak at impulse line Restricted impulse line (kinked, Intake air leak (throttle shaft, intake Ruptured vacuum slide diaphragm, Improper spring Jet needle position incorrect Incorrect pilot screw adjustment Fouls spark plugs, black, sooty exhaust Air intake restricted (inspect intake Air filter dirty/plugged Choke plunger sticking, incorrectly Choke cable binding or improperly Incorrect pilot air/fuel screw Faulty inlet needle and seat Faulty inlet needle seat O-Ring Float level too high Poor fuel quality (old fuel) Loose jets Worn jet needle/needle jet or other Dirty carburetor (air bleed Weak or damaged vacuum piston Fouled spark plug

  

 Idle Too Low

 improperly and seat screen or inlet passage

 

closed or inlet needle stuck

pinched)

ducts, airbox or air cleaner cover)

Vacuum slide stuck closed or sticky

RICH MIXTURE

Symptoms:

smoke, rough idle, poor fuel economy, engine runs

rough/ misses, poor performance, bog, engine loads

up, backfire.

adjusted choke

routed

adjustment

carburetor parts

passages or jets)

return spring

POOR IDLE

Idle Too High

 

mixture screw damaged

 

Idle adjusted improperly/idle

 

Sticky vacuum slide 

adjusted, routed incorrectly

 

Throttle cable sticking, improperly

adjusted, routed incorrectly

 

Choke cable sticking, improperly

 

Plugged or restricted idle jet

adjusted

 

Choke cable bending or incorrectly

 

Idle speed set incorrectly

damaged

 

Idle mixture screw misadjusted or

 

Belt dragging

 

Ignition timing incorrect 

 

Worn jet needle/needle jet

 

Plugged or restricted idle jet

adjusted

 

Choke cable bending or incorrectl 

 

Throttle cable incorrectly adjusted

(pilot circuit)

 

Air leaks, dirty carburetor passage 

adjusted incorrectly

 

Pilot mixture screw damaged or

Tight valves

Ignition timing incorrect

Belt dragging

Dirty air cleaner

Engine worn

Spark plug fouled 

limiter)

 

Idle speed set incorrectly (speed 

 

Worn jet needle/needle jet 

 

Plugged or restricted idle jet

 

 Erratic Idle

Symptoms:

popping through intake / exhaust, hesitation,

detonation, low power, spark plug erosion, engine

runs hot, surging, high idle, idle speed erratic.

 

Hard start or no start, bog, backfire,

 no fuel in tank 

CARBURETOR ASSEMBLY CONT’D

5. Install the pilotmixture screw, spring, washer, and

O-ring as an assembly. Lubricate theO-Ring with

oil or light grease before installation.

CAUTION:

Do not damage the O-ring during installation.

Turn the screw in until it

Back out the specified number of turns. NOTE:

The final pilot (idle)mixture must be adjusted with

the engine running. Refer to Page 2.11.

lightly contacts the seat.

Pilot Mixture Screw Base Setting

(Set at Factory)

Refer to Specifications Chapter 1

FLOAT HEIGHT

ADJUSTMENT

1. Place the carburetor on a level surface as shown

at right to remove weight from float arm. In this

position, the float tongue will rest lightly on the

inlet needle valve pin without compressing the

spring.

Float Height BST 34:

13--14 mm (.51--.55 inches)

2. Measure the height from the float bowl mating

surface to the top of step in float as shown. Both

sides of float should be parallel to each other. The

measurement should bemade at themid-point on

the top of the float using Float Adjustment Tool

(

measuring the height be sure the inlet needle

valve spring is not compressed.

3. If adjustment is necessary, bend the tongue

slightly. Be sure floatmeasurement is even on left

and right side.

Bend to adjust

float

Float arms even

PN 2872314) or a vernier caliper. When

NEEDLE AND SEAT

LEAKAGE TEST

1. Install the float bowl. Invert the carburetor and

install a Mity-Vac

fitting. Apply 5 PSI pressure to inlet fitting. The

needle and seat should hold pressure indefinitely.

If not, inspect needle and seat and seat O-ring.

 (PN 2870975) to the fuel inlet

FLOAT SYSTEM

Fuel enters the float chamber (3) bymeans of the inlet

pipe and passage, through a screen on the back of the

inlet needle seat (4), and around the inlet needle (2).

As the fuel fills the float chamber, the float (1) rises and

forces the inlet needle against the seat, shutting off

the orifice in the seat. When fuel level is up in float

chamber, floats are up and needle valve remains

pushed up against valve seat. Under this condition,

no fuel enters the float chamber. As the fuel level falls,

floats go down and needle valve unseats itself to

admit fuel into the chamber. In this manner, the

needle valve admits and shuts off fuel alternately to

maintain a practically constant fuel level inside the

float chamber.

Inlet

Pipe

1

4

2

3

MAIN SYSTEM

As throttle valve (1) is opened, engine speed rises,

and this increases negative pressure in the venturi.

Consequently the vacuum slide (2) moves upward.

The fuel in float chamber (3) ismetered bymain jet (4),

and the metered fuel enters needle jet (5), in which it

mixes with the air admitted through main air jet (6) to

form an emulsion. The emulsified fuel then passes

through the clearance between needle jet (5) and jet

needle (7), and is discharged into the venturi (A).

Mixture proportioning is accomplished in needle jet

(5); the clearance through which the emulsified fuel

must flow is determined ultimately by throttle position

and vacuum slide height.