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New 450X popping & Flame outs?

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Anybody have any tips?

I bought a brand new 450x 1st outing overheated pisted coolant, alot poping when getting out of throttle, would flame out and be hard to restart.

2nd outing no overheating but alot of poping getting out of throttle, still flaming out.

thanks

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The 450x comes waaaay lean from the factory to pass emissions in CA. Adjust the air screw out between 1.5 - 2 turns from all the way in. That should help.

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I agree... air screw 1 1/2 - 2 turns... I put a Zip-ty screw in mine to make it easier... also check your valves... my intakes as well as my buddies where both at 8 instead of 11... that combo fixxed mine..... I had major popping .... didnt Idle well and stalled easy..

now it runs perfect!... no other mods.. excepts guards...

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The X is really sensitive to the fuel screw. Seems that I have to play with it every time I go out.

Popping on decel means lean. Open the screw 1/8 - 1/4 turn. Stalling when getting back on the throttle means too rich. Close the screw a tad.

I like the Zip-Ty fuel screw for easy of adjustment, but I have to keep a rubber band around it to keep it from vibrating out of position. Don't know why it's doing it on this bike. Never had an issue like this on the other four bikes I've done this to...

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Besides the thins you fellars mentioned, which helped my bike run much better. After I installed the smog block off kit the popping went completely away.

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CRF450X - HOLLISTER HILLS , CA. 500 – 1500’ 50 – 68 Deg.

BONE STOCK JETTING: 168 MAIN / 45 PIOLT / 2.0 AIR/FUEL

WITH: APPLIED SMOG REMOVAL KIT

------------------------------------------------

WITH ALL MODS.

JETTING: 172 MAIN / 45 PILOT / 2.0 AIR/FUEL / STOCK NEEDLE # 5 CLIP POS.

ALL HRC MODS “THE WRENCH” (copy at all Honda dealers)

CRF450R MUFFLER With PRO MOTO END CAP – SPARKY ONLY

TWIN AIR COMPLETE AIR FILTER “KIT”

SCOTT EXTEND AIR FUEL SCREW

SCOTT S/S OIL FILTER

--------------------------------

CHANGES MADE SO BIKE WOULD LAST: GNCC RACES / FEW G.P. MX RACES:

CHAIN: DID MX520

PRO TAPER CR “HI-BEND”

TALLON HUBS: FRONT / REAR

ECELL RIMS: FRONT / REAR

BUCANON: 8MM SPOKES FRONT / REAR

FACTORY CONNECTION SUSPENSION

SCOTTS/OHLINS STEERING DAMPNER

ACREBIS HAND GAURDS

BRIGESTONE 201/202

RENTHAL REAR SPROCKET

OVERSIZED WAVE ROTORS : FRONT / REAR

ALL HONDA FLUIDS: HP4 10W/40W ENGINE OIL

HP TRANNY OIL 80W / 85W

Troubleshooting

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

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OK, now I'm going to show how mechanically pathetic I am. My 450X backfires big time when I let off the throttle. It's especially bad when engine-braking down hill. I looked at the owner's manual and there was no "air-screw" or "fuel screw" shown. I looked at the side of the carb (didn't remove it from the bike) and all I could really see to adjust was the idle speed screw. Where is screw that I should be adjusting, and is it an air screw or a fuel screw? (Sorry I'm such a moron mechanically, but I figure the only way to find out is to ask someone else who has done the adjustment).

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OK, now I'm going to show how mechanically pathetic I am. My 450X backfires big time when I let off the throttle. It's especially bad when engine-braking down hill. I looked at the owner's manual and there was no "air-screw" or "fuel screw" shown. I looked at the side of the carb (didn't remove it from the bike) and all I could really see to adjust was the idle speed screw. Where is screw that I should be adjusting, and is it an air screw or a fuel screw? (Sorry I'm such a moron mechanically, but I figure the only way to find out is to ask someone else who has done the adjustment).

Well if the 450X's carb is anything like the 450/R's then the fuel screw should be under/front of the carb, under the float bowl. normally facing the front of the bike. As for adjusting it, You might as well as rotate the carb because getting your hand in there is like sticking your hand in a pond of gators that havent been fed. I like many would really recommend you get the Zipty fuel screw. I makes things so much better.

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Thanks - I found it. Definately ordering the zip-ty screw tomorrow.

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Besides the thins you fellars mentioned, which helped my bike run much better. After I installed the smog block off kit the popping went completely away.

Same here. The applied racing kit cleared up 100% of my popping

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Thanks - I found it. Definately ordering the zip-ty screw tomorrow.

Once you get it installed, throw a rubber band around the end of it and the bowl of the carb. - not a tight one, just enough to keep a little pressure on it. My X seems to like to vibrate the setting loose. Dunno why, as I never had this problem on my 450R or the last two YZFs - just the X bike...

I know I have the 0-ring, washer and spring in correctly too...

Speaking of the o-ring, washer & spring - make sure you get them off the stock fuel metering screw and installed on the Zip-Ty unit in the correct order. - if memory serves (which is a big if!) the order is o-ring, washer then spring over the screw.

Wonder if I stretched the spring a tad... May put enough preload on it to keep the darn thing from backing out due to vibration.

Anyone else with an X seeing this problem? You can't loose the screw - it's stopped by the starter, but what a pain in the arse!

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The fuel screw adapters are very close to the top of the starter motor and I think it might hit when the going gets rough. I have looked for marks and haven't see any yet.

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The fuel screw adapters are very close to the top of the starter motor and I think it might hit when the going gets rough. I have looked for marks and haven't see any yet.
Mine sits about 1/16" of an inch above the starter motor. As long as it stays put (rubber band...), it's alright. You shouldn't have any issues with it hitting.

Once nice thing, (as if..) is that the screw can't fall out if it vibrates loose. - the starter won't let it. :applause:

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I turned my pilot screw an extra 3/4 out from the stock setting. Now when I chop the throttle, I still might get a little back-fire, but it's about 90% better than when the screw was in the stock position. Is it normal to have a small backfire when you do a full throttle chop, or should I keep turning the pilot screw out until the backfire is completely gone?

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i was experincing the same poping last night on decel going down hills, my pipe was also red hot from the cylinder to about a foot down the pipe. Both syptoms of being lean. Would a bigger main jet along with adjusting the airscrew help?

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If your fuel screw has a tendency to loosen up, make sure your not beyond 2 turns out...and if not, you can stretch the spring a tad to firm it up. I do this with a pair of stout needle nose pliers and just squeeze it a bit between one or two of the coils.

The reason for no more than two turns is, the window of adjustment is between 1 and 2 turns out. If your on either side of the scale there, you need to move the pilot jet.

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