Jump to content
Sign in to follow this  

new to four strokes.....

Recommended Posts

i just bought a 04 450r

I bought it with the carb off of it and after i put it toget her the bike would not idle unless the choke was on. i took the carb all apart and found nothing wrong, so i pulled the metering rod all the up and got to it idle with the choke off. i just rejetted it (the metering rod is still all the way up) and now it idles and starts fine, but if i throttle anything over idle it backfires out the exhaust. i have checked the valves and they are fine. i have never owned a 4 stroke and i am not sure what else to do....

also are is there any air fule adjustment screws on these bikes or just the idle screw?

Share this post


Link to post
Share on other sites

It sounds like it's way lean on the pilot. What jets are in it? The fuel screw is the small flat head screw sticking out the fuel bowl on the front of the carb (facing down). It may be turned all the way in.

Share this post


Link to post
Share on other sites

well that entire screw is missing so that may have alot to do with my problem .

not that this matters now but my jets are 170 main and 45 pilot. but i guess i will install that screw and start again with the stock jets. someone was telling me that it is possible to get that adjustment screw so you can adjust it with your thoum instead of a screw driver?

Share this post


Link to post
Share on other sites
i just bought a 04 450r

I bought it with the carb off of it and after i put it toget her the bike would not idle unless the choke was on. i took the carb all apart and found nothing wrong, so i pulled the metering rod all the up and got to it idle with the choke off. i just rejetted it (the metering rod is still all the way up) and now it idles and starts fine, but if i throttle anything over idle it backfires out the exhaust. i have checked the valves and they are fine. i have never owned a 4 stroke and i am not sure what else to do....

also are is there any air fule adjustment screws on these bikes or just the idle screw?

Bike won’t start after a crash

Pilot too lean

Idle set too high

Improper starting procedure

Bike wants hot start button

Bike runs on or won’t idle down when throttle is chopped

Idle set too high

Air leak intake or engine

Pilot too rich (when bike is hot)

Bike won’t start when cold outside

Pilot jet too lean

Air filter is over-oiled

Motor oil too thick for temperature

Bike sputters/won’t clean out at high RPM

Main jet too rich

Air filter is over-oiled

Spark plug has debris on electrode

Bike coughs and stalls in slow turns

Pilot too lean

Idle set too low

Valves set too tight

Decompressor is set too tight

Bike hesitates or bogs over deep whoops or G-outs

Float level too low

Carb vent tubes blocked

Main jet splash shield not installed

Float level too high, gas is trapped in vent tubes (install T-vents)

Bike starts but won’t take throttle without sputtering

Pilot jet too rich

Water in fuel

Debris in main jet

Bike suddenly starts sputtering/gas flows from vent tubes

Stuck float check valve

Debris in gas or carb

Bike runs hot/feels slow and flat on straights

Main jet is too lean

Fuel octane low, causing detonation

Bike coughs and stalls when you wick open throttle

Needle too lean

Slide cutaway too lean

Pumper circuit blocked or too lean

http://www.factoryconnection.com/index2.htm

BASIC SUSPENSION SET-UP

FORKS

When installing your forks torque the triple clamp pinch bolts to the manufacturer’s specifications (generally 15 - 16 foot lbs.) After you have installed the front wheel and slide the axle through, push down on the handlebars a few times to insure the axle lugs are seated squarely on the axle before tightening the axle pinch bolts. Improper installation can cause binding in the forks and harshness/stiffness in fork action.

RIDERSAG

Measurement A : Place bike on a stand, wheels un-weighted;

measure from the left inside fender bolt to a point on the rear axle.

Measurement B : With the bike off the stand, place the rider w/gear on

the bike in a normal riding position with feet barely touching the ground. Have someone measure between the same two points as before.

• Measurement A - Measurement B

Remember these are only “General” recommendations. Different riding styles, tracks and manufactuer brands may vary these set-ups. However, listed below is a good starting point to choose from:

125-650cc ..... 100-120mm

Too much rider sag indicates you must increase pre-load to the spring by turning the Spring/Pre-load Adjuster clockwise. (decreases rider sag measurement).

Too little rider sag indicates you must decrease pre-load to the spring by turning the Spring/Pre-load Adjuster counter clockwise. (increases rider sag measurement).

FREESAG

Measurement C : With the bike off the stand and the rider off the bike; push down on the back end and let the bike come up by itself. Measure between the same two points as before.

Measurement A - Measurement C (Generally 25 - 35mm)

If you set your rider sag and your free sag does not fall within the recommended range; a spring change may be needed.

HINT: Less than 25mm generally indicates a stiffer spring is needed and more than 35mm indicates a softer spring is needed.

NOTE: 1" = 25.4 mm

Share this post


Link to post
Share on other sites
well that entire screw is missing so that may have alot to do with my problem .

not that this matters now but my jets are 170 main and 45 pilot. but i guess i will install that screw and start again with the stock jets. someone was telling me that it is possible to get that adjustment screw so you can adjust it with your thoum instead of a screw driver?

SCOTT EXTEND AIR FUEL SCREW

Share this post


Link to post
Share on other sites
Bike won’t start after a crash

Pilot too lean

Idle set too high

Improper starting procedure

Bike wants hot start button

Bike runs on or won’t idle down when throttle is chopped

Idle set too high

Air leak intake or engine

Pilot too rich (when bike is hot)

Bike won’t start when cold outside

Pilot jet too lean

Air filter is over-oiled

Motor oil too thick for temperature

Bike sputters/won’t clean out at high RPM

Main jet too rich

Air filter is over-oiled

Spark plug has debris on electrode

Bike coughs and stalls in slow turns

Pilot too lean

Idle set too low

Valves set too tight

Decompressor is set too tight

Bike hesitates or bogs over deep whoops or G-outs

Float level too low

Carb vent tubes blocked

Main jet splash shield not installed

Float level too high, gas is trapped in vent tubes (install T-vents)

Bike starts but won’t take throttle without sputtering

Pilot jet too rich

Water in fuel

Debris in main jet

Bike suddenly starts sputtering/gas flows from vent tubes

Stuck float check valve

Debris in gas or carb

Bike runs hot/feels slow and flat on straights

Main jet is too lean

Fuel octane low, causing detonation

Bike coughs and stalls when you wick open throttle

Needle too lean

Slide cutaway too lean

Pumper circuit blocked or too lean

http://www.factoryconnection.com/index2.htm

BASIC SUSPENSION SET-UP

FORKS

When installing your forks torque the triple clamp pinch bolts to the manufacturer’s specifications (generally 15 - 16 foot lbs.) After you have installed the front wheel and slide the axle through, push down on the handlebars a few times to insure the axle lugs are seated squarely on the axle before tightening the axle pinch bolts. Improper installation can cause binding in the forks and harshness/stiffness in fork action.

RIDERSAG

Measurement A : Place bike on a stand, wheels un-weighted;

measure from the left inside fender bolt to a point on the rear axle.

Measurement B : With the bike off the stand, place the rider w/gear on

the bike in a normal riding position with feet barely touching the ground. Have someone measure between the same two points as before.

• Measurement A - Measurement B

Remember these are only “General” recommendations. Different riding styles, tracks and manufactuer brands may vary these set-ups. However, listed below is a good starting point to choose from:

125-650cc ..... 100-120mm

Too much rider sag indicates you must increase pre-load to the spring by turning the Spring/Pre-load Adjuster clockwise. (decreases rider sag measurement).

Too little rider sag indicates you must decrease pre-load to the spring by turning the Spring/Pre-load Adjuster counter clockwise. (increases rider sag measurement).

FREESAG

Measurement C : With the bike off the stand and the rider off the bike; push down on the back end and let the bike come up by itself. Measure between the same two points as before.

Measurement A - Measurement C (Generally 25 - 35mm)

If you set your rider sag and your free sag does not fall within the recommended range; a spring change may be needed.

HINT: Less than 25mm generally indicates a stiffer spring is needed and more than 35mm indicates a softer spring is needed.

NOTE: 1" = 25.4 mm

I didn't get all that, can you tell me again?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×