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Crf450r fuel screw issue

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I have the r&d bowl and am pretty sure that's set about right even tho I have to turn it down spit if low to get it to miss the slide so I just left it around 1 3/4 turns out and it barely hits the slide

Ncvs needle third clip

180 main jet

I had the 45 pilot in but had to turn it all the way out to 3 1/2 turns out for the rpms to be the highest.

So I cleaned the pilot circuit out with fishing line like suggested and put the 42 pilot jet in. I still have to set the fuel screw at about 3 turns out for the idle to be at its highest point, all other jets, air jets and such are the factory spec ones... I know 3 turns out it too much for the pilot but Havnt heard of anybody needing a larger pilot in these bikes... Bike runs good but sometimes stalls when I'm low rpms rock climbing and such, might be due to running a factory flywheel tho... Any suggestions because I'm all out of ideas and tried about everything. Once again the bike runs real good I just know that whole pilot jet is funny. Oh and now that the 42 is in it cranks without the choke... Any ideas?

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Either your hot start is not seating/stuck/corroded and leaking, or your slide is way to high.

 

Set the fuel screw at 1.5

Start the bike, and lower the idle as low as it will go.

Then raise the idle with the fuel screw

If it goes to high, lower it with the idle screw, and repeat with fuel screw

 You should be using a 45 pilot.

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Either your hot start is not seating/stuck/corroded and leaking, or your slide is way to high.

Set the fuel screw at 1.5

Start the bike, and lower the idle as low as it will go.

Then raise the idle with the fuel screw

If it goes to high, lower it with the idle screw, and repeat with fuel screw

You should be using a 45 pilot.

I thought maybe some air was getting by the factory hot start nut so I replaced it. And over done the whole set the idle down but the fuel screw keeps idling best at three full turns out... I'm listening to what your saying but I believe I've already done that. Slide is too high? How do I adjust that? And that would explain the fuel screw being that far out needing more fuel right?.. I'm listening. Appreciate it btw

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Did you inspect the hot start plunger and cavity?

 

Is your fuel screw oring intact?

 

Have you checked for air leaks using spray brake cleaner? On the carb, air boots, header?

 

Is you slide vacuum plate in with the hole on the bottom?

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Did you inspect the hot start plunger and cavity?

Is your fuel screw oring intact?

Have you checked for air leaks using spray brake cleaner? On the carb, air boots, header?

Is you slide vacuum plate in with the hole on the bottom?

Plunger is clean with minimal grease.

New plate and seal with circle towards bottom.

Boots looked good and header is fairly new and dosnt backfire so I'm pretty confident it's sealed. How do I check for air leaks?

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With a hot running motor, spray brake cleaner on all carb junctions: top, boots, hot start, etc

 

If there is a leak, the motor will drop in rpms

Edited by TheKoolAidMadeMeSick

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With a hot running motor, spray brake cleaner on all carb junctions: top, boots, hot start, etc

If there is a leak, the motor will drop in rpms

So with the bike worm and running just spray the hell out of the carb and boots and see if there's a reaction?.. That's smart. Thanks man, I'll try it tomorrow afternoon and get back to ya on this Edited by Diggla117

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Yeah, you need the 45 in there to even get close on the fuel screw

Yeah I have one. I just took it out trying to get her dialed in. So even with the 13.5 piston and stage two 45 pilot is what should be in.. Will do. Appreciate fellas. This things been driving me crazy and I finally have it where it'll really run.. I'll be so happy when I figure out what it is

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Pilot and fuel screw is for idle only, unless WAY off

 

Main jet is for 3/4 to WOT unless main jet is WAY off

 

Needle jet and Jet needle cover the bulk of the throttle

 

If you carb is more than 150 hours old, REPLACE THE NEEDLE JET as it gets ovaled out causes strange symptoms.

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Pilot and fuel screw is for idle only, unless WAY off

Main jet is for 3/4 to WOT unless main jet is WAY off

Needle jet and Jet needle cover the bulk of the throttle

If you carb is more than 150 hours old, REPLACE THE NEEDLE JET as it gets ovaled out causes strange symptoms.

Brand new ncvs needle too. The rest of the random jets and rebuild kit are only about 30 hours old... I'm hoping your brake cleaner trick will reveal somethin

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Yes, but what about the age of the NEEDLE JET? (not the jet needle)

...also known as the 'emulsion tube'?

The copper two inch long piece that the needle rest inside of and main jet connects to? I replaced it about 30 hours ago BUT if the brake cleaner dosnt show anything then I'll put the old one back in and see what happens.. Appreciate the ideas/ help man

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Yes, but what about the age of the NEEDLE JET? (not the jet needle)

...also known as the 'emulsion tube'?

I just had it idling in the shop with a fan on the radiators and sprayed the shi out of the carb with brake cleaner and absolutely no change in idle speed. SO I'm going to put the old jet needle (two inch copper piece the main jet screws into and meddle rest inside and put the 45 pilot back in

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... I'm at a loss. I switched the needle jet, put the 45 in and even took the hot start lever off and made sure it was all the way in.. Sprayed is with brake cleaner and nothing changed. Went out and rode it and still.. It pops on decel and cuts off at 1 1/2 turns out and the idle steady picks up as I turn it out until about 3 1/2 turns out... I'm out of ideas

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No clue

You MUST have a lean condition to require so many fuel screw turns.

Have you checked the main air jet in the intake bell for clogging?

Is that the jet that's at the top of the circle part facing the intake? I don't know how else to word it... I guess I'll try running fishing line through there tomorrow then I guess. Appreciate the input man

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Remove the jet and inspect the passage

It is the only jet on the intake side of the carb

Will do first thing tomorrow. Thanks

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