Jetting

[RedSpecialized]

I think I need to change my name on here. Just to easily confused with @REDFOX (shawn). So shawn rides the CR that has been having jetting problems. He has had a few people help him out and it gotten better I think...? Still not great from what I hear.

I haven't had problems with the carb before on my bike. I have only ridden in cooler weather and lower altitide though and it ran perfect then. I guess I'm pretty ignorant with this jetting stuff. Didn't realize that elevation and heat could have so much effect on how it runs....:confused: makes me want the FI even more. Started the bike up at my house before leaving and rode around the block. Rode fine I thought. Then when it got up to parking lot, it was a little harder to start, but not bad. Then when we got to the bridge at the trail head, pull in my clutch and it died....took a while to restart, then got it started and every time I pulled in the clutch it would kill. So I crankedup the idle screw to see it that would help, it did a little bit, it only killed half as much then. It was popping and stutering bad. So I finally made it to where @double moo was waiting. Told him to just go head because wouldn't run unles I had the throttle have way open. I rode up just a little further then had to turn around. My foot has a big bruise from kicking it so much. Almost left that POS on the side of the mountin I was frustrated. I'm hoping all ihave to do is change the main jets, but don't know much about carbs on bikes.

So @MTNTSEEKER, i'll still take the $50 if you want, never turned down free money....:D

Pretty bumbed that didn't get ride with all these GREAT riders, but what I did ride of that trail was awesome. Looks like you guys had a great ride though. On the way home I stopped and looked at some new rides, that new FI WR looks nice!!

[Reedus]

I think I need to change my name on here. Just to easily confused with @REDFOX (shawn). So shawn rides the CR that has been having jetting problems. He has had a few people help him out and it gotten better I think...? Still not great from what I hear.

I haven't had problems with the carb before on my bike. I have only ridden in cooler weather and lower altitide though and it ran perfect then. I guess I'm pretty ignorant with this jetting stuff. Didn't realize that elevation and heat could have so much effect on how it runs....:confused: makes me want the FI even more. Started the bike up at my house before leaving and rode around the block. Rode fine I thought. Then when it got up to parking lot, it was a little harder to start, but not bad. Then when we got to the bridge at the trail head, pull in my clutch and it died....took a while to restart, then got it started and every time I pulled in the clutch it would kill. So I crankedup the idle screw to see it that would help, it did a little bit, it only killed half as much then. It was popping and stutering bad. So I finally made it to where @double moo was waiting. Told him to just go head because wouldn't run unles I had the throttle have way open. I rode up just a little further then had to turn around. My foot has a big bruise from kicking it so much. Almost left that POS on the side of the mountin I was frustrated. I'm hoping all ihave to do is change the main jets, but don't know much about carbs on bikes.

So @MTNTSEEKER, i'll still take the $50 if you want, never turned down free money....:D

Pretty bumbed that didn't get ride with all these GREAT riders, but what I did ride of that trail was awesome. Looks like you guys had a great ride though. On the way home I stopped and looked at some new rides, that new FI WR looks nice!!

Might be of some help. What is the make and model of the bike? What is your current jetting set-up? Sounds from your post that you have a fuel screw that is out of adjustment and/or clogged. Common misconception is for people to mess with the main jet when they have trouble with jetting. The main jet ONLY affects performance from half throttle to wide open. The idle has to be solved first before you even think about touching tha main. Keep me updated and lets get this issue worked out.

[fourtycal]

Looks like a great ride. I was riding Strawberry ridge at the time, sorry I missed it.

[RedSpecialized]

Might be of some help. What is the make and model of the bike? What is your current jetting set-up? Sounds from your post that you have a fuel screw that is out of adjustment and/or clogged. Common misconception is for people to mess with the main jet when they have trouble with jetting. The main jet ONLY affects performance from half throttle to wide open. The idle has to be solved first before you even think about touching tha main. Keep me updated and lets get this issue worked out.

Its a kx450f 08' I don't know what the current jetting set up is. Its ran great since I boughtthe bike early this year, so have never even messed with the carb. I did try adjusting the fuel screw a little bit on the trail sat, but it didn't really seem to do much when it turned the screw. I wa going to look at the carb. Tonight and give it a cleaning. Haven't done that since I purchased it. I do know the bike was last titled in CA, I bought it from a repo guy, so maybe it set up for lower alt. of CA.....???

[Mtnseeker1]

Sorry redspecialized I was cunfused.
Thought this was the red bike that has had some carb probs since the biggining +or-.
But just for giggles and grins is the hot start pinched in any way or better yet when at home and at idle can you turn your forks both ways 100% without any issue at idle?

Here's to hoping it some simple little thing. Cheers

I did notice at one stop by some vault toileys up high that the elev. was something like 8620 just north of where you can drop down into the falls by the LDS conference camp I think it was or BYU something or another. Cascade springs maybe. I do have one of those stupid little maps here somewhere but can't seem to find my magnifying glass LOL. Oh it was the summit parking lot that was this elevation. Found the glass LOL.

That'd be a real push for a bike that was jetted for CALI.

I bought 40cals old YZ and he lives in SLC area and she works great from 2200ft to about 8k then it gets harder to start but ran good enough up to 9k.

Story short check the simple stuff then maybe jetting.

[REDFOX]

Some things that I have learned since working on the honda jetting. The brand and type of silencer and exhaust ( power bomb header ) all come into affect on the jetting set up. There are numbers on all of the jets as well as the position of the clip on needle. Of course finding the right combination is the next to impossible thing to accomplish. While we are on the subject. Which jet would you recommend changing for a bike that is hard to start after it is warmed up ?

[Mtnseeker1]

Depends on what the main seat is sitting on 1,2;3 and I think yours has a number 4 but if you are on 2 go back to the top one to get things Started. then adjust. slowly one step at a time.OR BETTER STILL BACK TO SOCK it will treat you right up to 10k elevation..........with only a 15-20% drop in power.
TO many adjustments at one time will **** you up every time.............................................. .............
THis is the clip for the slider that I speak of.
It is a long and slow process and I recomend a big blue tarp out in the field to deal with it as so.
Personally I have thirteen jets that I carry with me for the beast XR just in case I'm in a bad way.
My way of thinking is one day I'll be into the 14teeners in Colorado and if I have them with me I can adjust to it all.

But the key here is take your time and if you can ride out in the field while doing it the better.

PS take a note pad as well and take notes as to how it is going down.
But all this being said I highly reccomend setting it up stock and deal with it any way you have to.

You can only make so many adjustments in a day but before long you'll se a pattern that will help.


ONE THING THAT I have noticed is when you beef up your exhaust and it runs like crap it is rarely the jetting unless you have set yourself up with the top of the line race pipe. Some will say different but I just don't buy it. It is a carb simple adjustment at this point period.......................... Simple carb adjustment is not jetting.
It is in fact a simple air / fuel mister thing and may take afull turn left or right to adjust to.
Listen to your motor if it is popping and running to hot turn that bitch to the left and rich it out some.if it just won't keep running and is hard to start then go right (LEAN) Of course this is backwords pending just how you precive it so lets make it simple : all the way in is leen and all the way out is rich.
Hope like hell this has you on top of it or so damb cofused that you take it to a pro and be done with it already.LOL 1and 1/2 out is a good place to start......


THere are so many factors it is unreal: what kind of anti freeze are you running , plug typweand, gap, Gas is it 91 and better octane and remember it goes down a percent by the day if left in the sun or back of the truck while riding. Is your exhaust packing up to grade? Like I say there is tons of things that will affect it all.

In short jetting is a last result until you have gone through all and any bugs that may exsit.

[REDFOX]

I have checked everything including the valves and for air leaks around the rubber boots on the carb. I am getting close but now the motor is hard to start when it is running normal tempeture. I feel like it is getting too much fuel while kicking it. This was never a problem before I started messing with the jets.

[Mtnseeker1]

Accelerator pump diaphram is the first thing that comes to mind at this point.
Or one of those tiny little o-rings for air fuel mixture etc.
Did you check valve clearences cold?
I know dumb questions but always worth asking.

Are the FLoats adjusted right???????

[REDFOX]

Valves were checked cold, I am thinking the accelorator pump also, Jd Jetting ( James Dean ) sent me an email talking about modifying the pump. I having nothing to lose by grinding on it as he says at this point. I bought a R&D racing flex jet remote mixture screw because I lost the o- ring and small flat washer twice since messing with the carb.

[Mtnseeker1]

Dang, Glad to see your getting down right serious about this .

Best of luck to your bro and let us know how it all works out.

But most important of all is lets ride.