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2008 CFR450R carburetor removal Q

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My bike was left for a year with the fuel valve in the on position, and when I got the bike back, the tank was substantially lower than I had left it, so my presumption is that fuel ran through the carburetor and either into the crankcase or elsewhere, 

Im looking at the carb and I can't see how to pull it off AND get the throttle controls off.   I'd like to take it apart and clean it.  Or take it to a shop and let them clean it  I've rebuilt a few carbs for automotive/marine applications, but never a bike.

Also, I have a clutch issue so if anyone has a recommendation for a shop in Austin TX that I can take the bike to for that, I would appreciate it.  The clutch does not ever ful The clutch does not never fully disengage.  I ordered a new tusk clutch kit + springs and Barnett basket, but when I pulled the clutch assembly apart, it all looked relatively new  

 

Edited by barronj

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Ok, are you going to take it to a shop? Or do it yourself, because neither job is a very big deal. The throttle cables come off by first removing the black cover that is retained by a single shouldered allen screw on the right side of the carb. Once that is removed, loosening the cable housings will allow you to remove the cables. At that point, there are clamps that retain the carb in the boots. Don't forget to remove the TPS sensor. Do not try to separate the upper and lower carb body halves. Its not difficult, but you wont be able to get a replacement gasket.

Douche the carb body with carb cleaner and compressed air through every orifice like you were going to have it surgically implanted in your body. Simply removing the jets and replacing them isnt a bad idea. Not necessary, but some guys dont feel like they can get the pilot jet entirely clean. If you have it out of the carb, you should be able to get it clean. 

Now, your clutch. You say its not fully disengaging when you pull the lever. Assuming the play in the cable is correct, and the cable isnt absolute junk, there are a couple of things. One would be the fingers in the clutch basket. They get notched up and prevent the plates from properly floating allowing the clutch to disengage. They basically wedge-mate themselves to the basket in the engaged position. Lifting the pressure plate ends up doing very little and the clutch doesnt slip. You can replace the basket and cure the whole thing if that's the issue. Second possibility would be someone slipped the clutch like a maniac, over heating it intensely. This can allow the steels to warp. When they warp, pulling in the lever doesn't lift they pressure plate far enough to clear the warped plates, so they continue to drag. Its usually either or, but can be both. You wont know until you take it apart and look.

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I have the same bike and on removing the TPS is there anything that needs to be lined up or watched when removing it or re-installing it? .. I looked around, but didn't see anything in regards to this?

Also those mid-body gaskets are still available ... like 30 bucks ;) 

 

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Sorry,. but I was wondering if you have to loosen the subframe and remove the rear shock to get the carb off of these CRF450's? ... I saw a vid that they recommended that (?)

Looks like the carb should be able to come right out through the top where the tank was ...?

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10 hours ago, WERNER1 said:

Sorry,. but I was wondering if you have to loosen the subframe and remove the rear shock to get the carb off of these CRF450's? ... I saw a vid that they recommended that (?)

Looks like the carb should be able to come right out through the top where the tank was ...?

It will, but its a huge pain in the ass. Just pop the shock out, it's way easier. And dont take the TPS off. There's no reason to.

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The TPS will just unplug, it's about 12" of wire up to where all electrical connection are on the right side of the bike.

I plucked the subframe off tonight in 10 minutes, unbolted the top of the shock and let it fall back, pulled the carb out through the top after disconnecting the linkages.

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Ok thanks again for the replies! 

I have to change the spring on the rear shock anyway, so I'll just plan on doing all of that at the same time.

TPS - I know it doesn't have to come off but I want to pull the slide out and check/change the seal on it as well as regrease the shaft bearings which will require pulling the shaft out from the throttle side and disengaging the TPS - didn't know if there was a process to putting it back together or re-aligning the shaft with the TPS -  I have a Clymer manual on order,.. need to see if there's an online download source for the factory service manual for an 07/08 CRF450R 

Sorry,.. don't mean to hi-jack :D

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I had to take the sub frame off and unbolt the shock at the top to let it fall back and give myself room to get things apart. There is some kind of aftermarket air filter and it was in sore need of cleaning, so I cleaned it and sprayed it with K&N oil, it's a reusable type. I cleaned the top part of the carburetor but a screw head stripped on the bottom part and I couldn't get the bottom off, so I sprayed carb cleaner in the fuel inlet, shook it around and let it drain out. New spark plug, fresh oil (it would appear that's where the gas went), drained the tank and rinsed it with fresh gas, then refilled it after cleaning the fuel filter, the bike fired up on the second kick and it's never done that. Took it for a short ride around the neighborhood.

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Shawn_MC

I must have changed a throttle setting.  It's idling higher now.  I had to loosen the throttle linkages to disconnect them, I think I made one shorter (or longer) in the reconnection process and it affected my idle.  I've lowered it with the idle set screw, but I'd rather rebalance it where I created this issue.  Do I adjust the upper or lower linkage, and should I do it at the carb again, or adjust from the throttle?

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11 hours ago, WERNER1 said:

Ok thanks again for the replies! 

I have to change the spring on the rear shock anyway, so I'll just plan on doing all of that at the same time.

TPS - I know it doesn't have to come off but I want to pull the slide out and check/change the seal on it as well as regrease the shaft bearings which will require pulling the shaft out from the throttle side and disengaging the TPS - didn't know if there was a process to putting it back together or re-aligning the shaft with the TPS -  I have a Clymer manual on order,.. need to see if there's an online download source for the factory service manual for an 07/08 CRF450R 

Sorry,.. don't mean to hi-jack :D

TPS doesn't need to come off to pull the throttle shaft arm, shaft and slide out. There is a process to get it back together, the shaft/spring has to be put in a certain way and the shaft has to engage the TPS a certain way. I'll post some pics tomorrow.

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No need to pull shafts to remove slide. Just unscrew slide lifting arm from shaft and lift out slide and arm.
That K&N filter oil is gonna make a mess below airbox as gravity does it's job and leaves filter barely oiled. Go with a "sticky" foam filter oil such as maxima fft. Many other brands available. The K&N oil may lead to a lean condition also.

Sent from my SAMSUNG-SM-N900A using ThumperTalk mobile app

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OMG, I assumed that the sticky filter was old filter oil gumming up. 

 

 

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2 hours ago, Red800rider said:

No need to pull shafts to remove slide. Just unscrew slide lifting arm from shaft and lift out slide and arm.
That K&N filter oil is gonna make a mess below airbox as gravity does it's job and leaves filter barely oiled. Go with a "sticky" foam filter oil such as maxima fft. Many other brands available. The K&N oil may lead to a lean condition also.

Sent from my SAMSUNG-SM-N900A using ThumperTalk mobile app
 

Good point. I've taken mine out to give everything a good cleaning and he did mention giving the shaft bearings a greasing. Gotta' remove the shaft for that.

Edited by HRC27

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13 hours ago, HRC27 said:

TPS doesn't need to come off to pull the throttle shaft arm, shaft and slide out. There is a process to get it back together, the shaft/spring has to be put in a certain way and the shaft has to engage the TPS a certain way. I'll post some pics tomorrow.

Ok, first of all, forgive my filthy carb.  Secondly, I've left off the shaft arm and washers for clarity.

1. Note that the more curved end of the spring faces inward.

2. The more sharply bend attaches as shown.

3. With one thumb, push the accel pump bits to the right and hold them there throughout the install.

4. Install the shaft with with cable holes facing roughly 3:00-4:00.

5. Note where the spring engages.

6. Turn the shaft  counter-clockwise until the shaft is in the positioned as shown.

7. Insert in to bearing and TPS fully, you can now let go of the accel pump arm, etc.

I've included a pic of the seal orientation (you can get it in wrong) in case you find that your's is bad.

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I've had a few of the FCR Completely apart in the past,.. but I typically removed the whole TPS stuff as it wasn't needed on those applications (Installing these carbs on different bikes/ATV's) .... From what I remember the end of the shaft is slotted to received the tab of the TPS, and I think the TPS is spring loaded to some degree,.. probably for resistance to go back to "0" when the throttle is released..?

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Thanks for posting the pics HRC27! Uhm... yeah,.. might want to cleaner' up a bit :D  ... did you change out that slide gasket/oring?

Barronj - reading back through this on your original problem and progress -

1 - If you use a small pair of curved (or flat) jawed vise grips, you should be able to get those bowl screws out to gain access to the jets/float assembly for better cleaning. - I will typically purchase a Stainless steel Allen Head screw set for the carb and change them all out (Kit covers the bowl, AP, and slide cap) ...it's like 6 bucks I think on ebay.

2 - Idle - hard to tell exactly what changed, but there should be a slight amount of slack in the throttle cable(s) so that the throttle tube has some play in it where it can move a little bit with out actuating the slide. Make sure your slide is returning back to the Idle adjustment stop (the knob your turn to adjust your idle) ... I've had them hang up a bit and hold a higher idle and have to physically push the slide down to get the idle to come back down (I had the air box to carb tube off at the time )

3 - Fuel Screw - once your sure that the cables and slide are working properly and not hanging up or binding,.. then you can move on to the fuel screw - bike needs to be warmed up to adjust -

 

Just some thoughts :)

 

here's some pics of an FCR project I did recently retrofitting an 39mm FCR off of an 06 yFZ450 onto an 03 KFX400 using a custom intake, 400EX air tube and modding the air box... Made a HUGE difference! But it involved removing the TPS and Idle adjuster and then blocking that off and drilling and tapping a new access point for a flexible idle control ... fun stuff!

 

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Sad thing is I have all the parts sorted for a complete rebuild including a new vacuum plate and seal.  Dang garage is hot as sh-t!:banghead::facepalm:

Edited by HRC27

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haha I hear ya! ... luckly my HVAC system is in the garage and I have one Vent in there along with some residual air,... if the dang kids keep the garage door shut it's actually not too bad in there with a fan or two running,... Now having enough space to move around in there is another thing .. :(

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