2007 CRF450R Throttle Routing/Sticky/Problem?

[Coleg126]

Hello.  I am a new owner to a 2007 CRF450R.  When I got it home I started going through everything and its been coming along nicely till this throttle cable issue.  I noticed that the throttle retraction was slow.  I'm used to a snap back to the closed or idle position.  This was slugging and when the bars where fully turned to the right it sometimes would not even return to the closed position.  So I pulled the old throttle cables off put the new ones on and what do you know same problem.  I am concerned now about the throttle cable routing cause I am second guessing myself on the original routing.  I pulled the throttle tube and assembly off and cleaned it.  I pulled the throttle linkage cover plate off the carb and cleaned all that out.  However when only the lower throttle cable is connect to the carb it snaps back perfectly.  When I hook up the top cable is when all the problems start happening.  I usually can work through these problems but this one is killing me and i lost my patients today.  And with the constant taking off of the new throttle cables I tripped them and now they are junk.  I must of removed them a dozen times to try different routing.  Then when I had it working perfectly I put the fuel tank back on and that screwed everything up cause it pushed the cables down then kinking them or something cause it went back to not working again.  Can I please get some pics of the proper routing if anyone has them and any advice please.  Oh I also ordered a new throttle cable guide that is located inside the throttle assembly that mounts to the bars.  That little white plastic piece that guides the throttle cables that attach to the twist grip throttle tube.  Thank you.  

Edited December 17, 2017 by Coleg126

[S.O.A.N.Z]

Last diagram is a 250r - 04-07 but should be the same layout

[HRC27]

It looks like S.O.A.N.Z has you taken care of but make sure you have the pull cable at the throttle attached to the pull on the side of the carb. Same thing with the push cable. 

You can also make sure that the throttle tube is a little away from the bar end by loosening the housing, push it inward until it contacts then pull it out a little and tighten the housing.

[Coleg126]

Thank you for the diagram. I do have the routing correct and I have the push and pull cables attached correctly.  Still got the problem though. When I hook up the pull cable everything works perfect and when I hook up the pull and push cable it starts to act up. Do you think we could be talking about getting into the carb now?  Like a weak return spring?  It sure doesn’t feel weak when I move it with my hand.  The cable routing on this bike seems a little weird also. 

[HRC27]

If you disconnect the cables and pull the inner back and forth is it smooth?  Did you lube the cables before installing them.  I know they're new cables so they should be fine but I'd check that then clean the whole carb.  Just don't spray carb cleaner in the throttle valve area, you'll damage the floating valve seal.

Rocky Mountain ATV/MC has a good video on cleaning the FCR carb as well. Ty gets in to cleaning the throttle shaft and greasing it's bearings though.  Mine was a little sluggish so I followed his article. Works great now. ?

https://www.dirtrider.com/features/protips/141_0707_keihin_fcr_carb_rebuild

[dwight4039]

If it isn't the cable adjustment, it could very well be the tps. I have seen this twice, we marked the position good, removed it cleaned and lightly lubed it. Cured problem

[Coleg126]

TPS- The throttle positioning sensor?  yeah it’s just when the cables are not hook up the throttle return spring in the carb feel strong and snaps closed. I believe it’s in the routing of the cables.  Cause I’m different positions of the handlebars the throttle returns at different speeds.  No I didn’t lube the new cable.  Should a brand new cable need lube? 

[dwight4039]

1 hour ago, Coleg126 said:

TPS- The throttle positioning sensor?  yeah it’s just when the cables are not hook up the throttle return spring in the carb feel strong and snaps closed. I believe it’s in the routing of the cables.  Cause I’m different positions of the handlebars the throttle returns at different speeds.  No I didn’t lube the new cable.  Should a brand new cable need lube? 

My bad,should've read it better. Check the inside of the throttle housing on the bars,one of the halves tends to wear more I can't remember which and allows the tube to bind on return. Also look close at the slider the cables run in. I keep one of those in our parts kit because of how the cable wears on it.

Edited December 18, 2017 by dwight4039

[HRC27]

1 hour ago, Coleg126 said:

TPS- The throttle positioning sensor?  yeah it’s just when the cables are not hook up the throttle return spring in the carb feel strong and snaps closed. I believe it’s in the routing of the cables.  Cause I’m different positions of the handlebars the throttle returns at different speeds.  No I didn’t lube the new cable.  Should a brand new cable need lube? 

You don't "have to" but I always do.

[Fred X]

If you want to lube a cable invest in a tool that clamps on the end and has an opening to insert the cable lube spray tube, do not use chain lube.  It will be sealed tight and clean beyond belief at your filling end and push out black gunk on the other end.  Keep that tool with the cable lube forever.

Throttle goes behind other cables and gets first pick through the forks staying tight against the frame. Most importantly straight is better and don't ever change directions or try to quick turn over a harness, hose or tank rubber.  It is engineered to fit as long as bars are not wider or your grip is dragging on the end.   A push cable cannot be a problem unless it is burred horribly and that would be easy to check before connecting to the carb end.  Just like turning a bearing by hand to sense for anything less than super smooth.  Keep in mind that when installed there should be a position of not necessarily slack but at least very minimal zeri tension so if that is not achieved look at the adjusters. 

 

This would all be helped first with the tank off and squatted on the right side looking at changes in the cable attitude.  Same while turning bars where you might not even have to operate the throttle.  i suggest you look at the TPS to if nothing else make sure you don't cause it damage in the future.  But I would not open the carb if you were having trouble as the needle clip and assorted other items will be in play.  Just make sure you crack the drain screw on the carb after every ride with the petcock off and let it run dry, might never go inside ever.  If left for no more than 2 months easy to run with petcock open till fuel overflowing changes from yellow to clear.   Back at the carb parts and internal spring.  Push pull has a big spring on the mechanism and you could test the open close with your hand realizing how hard it is to open without leverage and how quick it smacks back.   If I frayed a cable I am ok with a pull only but then I am not being certified by a racing association before or after a race.

 

[karussi]

Its that little white plastic bit inside the throttle housing that routes the cables out of the housing.  Happened to me on my 07 CRF450R and took me a week to figure it out.

[Coleg126]

Yeah parts ordered. I am out of town for work. When I get home and replaced I’ll let you know how it goes.  Thanks for all the input.  

[Shawn_Mc]

Make sure the slide is running freely in the carb. Guys are assuming throttle cables yada yada.... I've fixed this issue dozens of times on dozens of bikes. It's usually a throttle tube that's bad or a throttle slide in the carb that's binding.

The slide can bind for a couple different reasons. The plate is bad, worn etc. The wheels have gotten gummy. Rotate the throttle wheel and make sure the throttle slide snaps back, then work the issue back to something that finally drags a bit.

Clean the throttle tube and the housing like you were going to have it implanted  in your body. I lube the throttle housings and bits with spray silicone. Let it dry. It wont attract dirt at that point either. Make sure there is some play in the cables too. If you suck all the play out, you bind the throttle tube on the handle bar in the housing and it wont spin freely.

[Coleg126]

Sorry guys.  I am still out of town for work.  When I was home working on the bike I tore the carb apart and completely cleaned it.  The linkage was a little gummy.  The slide seemed very clean.  That little rubber o ring/diaphram flimsy thing on the back of the slide was almost loose in its housing.  Anyone seen this?  After I cleaned that area it seems like it shrunk back up and seated back into its home.  It isnt ripped or anything I reinstalled and it seems like the slide is working perfectly.  The part is called the valve set floating.  When I got the carb off I also noticed the the hot start assembly was stripped that screws into the carb so waiting on a few more parts before it goes back together.  I am keeping my fingers crossed this throttle issue is resolved.

[HRC27]

6 hours ago, Coleg126 said:

Sorry guys.  I am still out of town for work.  When I was home working on the bike I tore the carb apart and completely cleaned it.  The linkage was a little gummy.  The slide seemed very clean.  That little rubber o ring/diaphram flimsy thing on the back of the slide was almost loose in its housing.  Anyone seen this?  After I cleaned that area it seems like it shrunk back up and seated back into its home.  It isnt ripped or anything I reinstalled and it seems like the slide is working perfectly.  The part is called the valve set floating.  When I got the carb off I also noticed the the hot start assembly was stripped that screws into the carb so waiting on a few more parts before it goes back together.  I am keeping my fingers crossed this throttle issue is resolved.

Did you get one of these?  Billet aluminum instead of the OEM plastic one and has a 10mm (instead of 14mm) head so easy to get a wrench on.

https://www.ebay.com/itm/Keihin-FCR-Carb-Billet-Hot-Start-Nut-Suzuki-Rmz-250-450-USA-Cable-RED/282013308947?fits=Model%3ACRF450R&hash=item41a94d9813:g:pAgAAOSwZB9aQtnp&vxp=mtr

[Coleg126]

I did after I bought the stock one. Oops. Thanks though seems way way better.  

[Shawn_Mc]

10 hours ago, Coleg126 said:

Sorry guys.  I am still out of town for work.  When I was home working on the bike I tore the carb apart and completely cleaned it.  The linkage was a little gummy.  The slide seemed very clean.  That little rubber o ring/diaphram flimsy thing on the back of the slide was almost loose in its housing.  Anyone seen this?  After I cleaned that area it seems like it shrunk back up and seated back into its home.  It isnt ripped or anything I reinstalled and it seems like the slide is working perfectly.  The part is called the valve set floating.  When I got the carb off I also noticed the the hot start assembly was stripped that screws into the carb so waiting on a few more parts before it goes back together.  I am keeping my fingers crossed this throttle issue is resolved.

The way to go about this is to make sure that with the throttle cables in the throttle housing, but not installed on the throttle wheel yet, that there is no resistance in the throttle action. Zero. None. When you've got that nailed down. and the slide snaps back in the carb without the cables attached...then put the cables on. That way, you'll know what are where the issue is, if it comes back. And when you mount the throttle housing on the handle bar, push it all the way in, then back out about 1mm or so the end of the bar isnt dragging on the inside of the throttle tube.

[Coleg126]

Ok so I am 99% sure this is a throttle cable routing issue. When the throttle cables are completely hooked up without the fuel tank on it works perfect. As soon as I put the tank on and the throttle cables get rerouted some it works perfect until the bars are turned to the right then in gets stuck. Talk about frustrating.  Shawn I did exactly what you said with the throttle assembly on the bars. Cleaned it likenit was being implanted into my body. Backed of off about a millimeter. Pulled the carb completely cleaned it. And it snaps back perfectly with the cables disconnected. T also snaps back perfectly even when they are connected just not when the bars are turned to the right.  Maybe some details pictures of how yours is. The way it’s currently routed is exactly like the diagram on the top of this thread. This is getting frustrating.  

[HRC27]

Looking from the top, move the cables to the right as much as you can then set the tank down.  I've had them get bound between the tank and the valve cover before.

[Shawn_Mc]

On 12/29/2017 at 6:28 PM, Coleg126 said:

Ok so I am 99% sure this is a throttle cable routing issue. When the throttle cables are completely hooked up without the fuel tank on it works perfect. As soon as I put the tank on and the throttle cables get rerouted some it works perfect until the bars are turned to the right then in gets stuck. Talk about frustrating.  Shawn I did exactly what you said with the throttle assembly on the bars. Cleaned it likenit was being implanted into my body. Backed of off about a millimeter. Pulled the carb completely cleaned it. And it snaps back perfectly with the cables disconnected. T also snaps back perfectly even when they are connected just not when the bars are turned to the right.  Maybe some details pictures of how yours is. The way it’s currently routed is exactly like the diagram on the top of this thread. This is getting frustrating.  

Thats a cable routing issue through the bars, around the triple clamp thing. You may need to pull the cables out of the throttle housing and make sure they dont cross each other more than once from where they exit the carb. And I think thats your issue. Somewhere, the cables are getting bound up upon each other. And they need to be able to move around a little from the housing all the way to were the go down into the frame. So if you've got them neatly zip tied and snugged up to one another and the number plate or something else, cut those off...