Carb question crf450r

I have a 04crf450r it runs great through out the power band... But I just had a few questions I put the jd jet kit in and it sometimes will almost stall the bike when I snap the throttle from an idle! It's not as bad once it gets wormed up but it will still bog I've played around with the jetting a good bit and I think I got it messed up a little the fuel screw distant seems make to much of a difference if I worm it up and lower the idle it makes a little difference but not much I can screw the screw all the way in and it will still run! I can't seem to fine tune it with the crew at all... And it is also really easy to start with out the choke starts right up every time could any body give me some pointers on what detection to go?

My pilot jet is a 48 and my main is a 175 red needle 5th clip down

You have a race bike. If it runs perfect once heated up, learn to be patient for the fifteen minutes it takes.

 

A bike that starts well cold with no choke typically has a too rich pilot circuit. If the bike still idles with the fuel screw closed, the pilot is too large. Get the right pilot in it and fine adjust the fuel screw for a strong, smooth idle with a hot engine.

 

If the bog is still there then you may have to work on the AP. A 04 Honda has the old style AP and can benefit from a different AP cam spring, no leak jet and sometimes a different AP diaphragm.

 

Remember a carb is made up of individual circuits, each designed and intended to do a particular job. They must be set right, in proper order and not tweaked to compensate for mis-adjustment elsewhere.

You have a race bike. If it runs perfect once heated up, learn to be patient for the fifteen minutes it takes.

A bike that starts well cold with no choke typically has a too rich pilot circuit. If the bike still idles with the fuel screw closed, the pilot is too large. Get the right pilot in it and fine adjust the fuel screw for a strong, smooth idle with a hot engine.

If the bog is still there then you may have to work on the AP. A 04 Honda has the old style AP and can benefit from a different AP cam spring, no leak jet and sometimes a different AP diaphragm.

Remember a carb is made up of individual circuits, each designed and intended to do a particular job. They must be set right, in proper order and not tweaked to compensate for mis-adjustment elsewhere.

Well I pulled my AP and this is what I found....ImageUploadedByThumper Talk1412471975.584609.jpg

I'm guessing this is a result from using carb cleaner on it... It has the first boyson quick shot AC pump on it... I will replace that peace. Will it be the same from oem since it has a different AC pump? Or is that part of the upgraded pump?

And would it be ok to ride it like this until I get the new part?

Edited by jsmxlove15

OEM diaphragm should be fine. Just make sure everything is well cleaned.

You should not run the bike without a diaphragm, it will leak fuel.

Carb cleaner is a No-No. Carb Parts Cleaner dissolves all plastic, rubber and and organic material. Only use brake Parts Cleaner or Electrical parts cleaner. Some use Simple Green.

OEM diaphragm should be fine. Just make sure everything is well cleaned.

You should not run the bike without a diaphragm, it will leak fuel.

Carb cleaner is a No-No. Carb Parts Cleaner dissolves all plastic, rubber and and organic material. Only use brake Parts Cleaner or Electrical parts cleaner. Some use Simple Green.

so I got a new diaphragm and installed it and but it didn't help the problem at all seems like the squirt isn't hardly anything at all and is very weak I'm just wondering if I should order some new leak jets? And what made it change from when I first bought the bike about 3 months back? The bog just seemed to get worse and worse! Do I need a different diaphragm with a shorter post on it? And if so where would I get it? Sorry for all the questions but I am very thankful for any help I can get

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I'll

 

so I got a new diaphragm and installed it and but it didn't help the problem at all seems like the squirt isn't hardly anything at all and is very weak I'm just wondering if I should order some new leak jets? And what made it change from when I first bought the bike about 3 months back? The bog just seemed to get worse and worse! Do I need a different diaphragm with a shorter post on it? And if so where would I get it? Sorry for all the questions but I am very thankful for any help I can get


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I'll bet you the passageway from the AP chamber to the nozzle in the carb is clogged. You should also check the one way (check valve) in the float bowl.

I'll

I'll bet you the passageway from the AP chamber to the nozzle in the carb is clogged. You should also check the one way (check valve) in the float bowl.

i took the bowl off and the AP and blew it all out and took out the leak jet blew it all out and the one way check vale!

But I bet you are right about the passage way clogged. What is the best way to clean it?

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Edited by jsmxlove15

Sent from my iPad using Thumper Talk. but I bet you are right about the passage way! What's the easiest way to clean that?

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Edited by jsmxlove15

Spray compressed air and Electrical Parts Cleaner or Brake cleaner (both chemicals are rubber safe). Some carefully poke monofiliment fishing line up. Note, the nozzle is a 90 degree turn at the tip so the line will not pass all the way through. One TTer used a syringe filled with mild solvent. He found the high pressure he could create using the syringe blew the debris out. Wear safety glasses and be cognizant of the direction  of the spray.

Ok I will try that thank you!!! :)

I find the nozzles to clog easily

Using real carb spray cleaner (holding the slide up so as not to damage the seal) I spray up via the angled passage, to the nozzle

Let it sit 15 min a repeat until it flow well

If all else fails, an extremely fine steel wire (NOT a acetylne torch tip cleaner) into the nozzle to help it along

Your pilot is probably too big. If you have a clogged jet or orifice use copper wire or fishing line

You could have put too big of a jet size. I tried upping my jets on my Rmz 250 and it also bogged down when I hit the throttle. I went and order the stock sized and it fixed the problem. Possible when u snap the throttle it floods out for a second. Cause if it still runs that means it's getting too much gas. That what I would suggest. I would only up the jets if u got cams or ported intake or something like that. Trying to up the carb with everything else stock might not work out

Ok so I'm in the process of cleaning out the AC nozzle and I had the bowl off and I filled the bowl with gas and stuck a rod down there and was pushing on the Diaphragm and it was just barely blurting out... and how do you know when the nozzle is completely unclogged carb cleaner squirts through it and didn't seem like there's that much resistance there? Would it be good for me to get an 07 diaphragm?

The check valve must be working too

Just upgrade to a 2008 CRF system and be done with it

Edited by Kah Ran Nee

The check valve must be working too

Just upgrade to a 2008 CRF system and be done with it

do you mean buy a new carb?

The check valve must be working too

Just upgrade to a 2008 CRF system and be done with it

ImageUploadedByThumper Talk1413070685.299561.jpg thats the squirt I'm getting dosnt seem to be clogged at all... But it sure dosnt last for a full second. It seems like it's not a pressured squirt.. Would a smaller leak jet fix this?

I am thinking about buying the boyesen quickshot 3 would you recommend buying it? wold it take care of my problem>?

I am thinking about buying the boyesen quickshot 3 would you recommend buying it? wold it take care of my problem>?

 

NO NO NO NO

 

That is carb jewlery

 

Your squirt looks fine. 

It will not be full squirt for 1 sec unless the leak jet is 50 or below, and the diaphragm pin is short, and the rod is long to match the diaphragm.

1 sec is very short

 

 

 

If you read the link I posted, it explains exactly what to do.

 

You have these components of the apump system

 

Leak jet ; fills the apump cavity to a certain level; a smaller jet gets you more fill

Diaphragm: short, medium and long rivets determine how much gas actually gets squirted. Short is the largest gulp/biggest squirt (2008)

Diaghragm actuation rod: Needs to be long enough to push the short rivet diaphragm (2008)

Linkage spring: determine how well the diapragm gets pushed, and how well in relation to the throttle linkage. The stiffest spring is needed to work well (Tokyo mods, Merge racing)

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