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quick ? about the ktm carbs. ive installed the jdjetting kit and the exhaust mod. jd also recommends for "closed course" riding that a few vacuum hoses be changed up. mostly to free the carb vent and remove a vacuum source from the engine. if you look at the link below you can see what they recommend. my ? is this: why not take all that emissions stuff off? ive removed the canister(which was in the airbox), ive removed the air valve(it was hooked to the before mentioned tank vent) and all the remaining hoses for those two. the only hoses that remain and attach to the "catch can"(which jd says to leave the plug out of the bottom of it) are the carb drain(which i know can just hang there hooked to nothing) and 4 hoses that go to the top of the carb(2 on each side hooked to "t"'s). can i take off the catch can and leave those 4 hoses hanging exposed to the elements?

http://www.pbase.com/jdjetting1/450_525_530&page=1

this link shows one side of the carb and the hoses im asking about, its the "t" connection right behind the choke knob

http://www.pbase.com/jdjetting1/image/114703570

let me know what you think, thanks joe

btw- with all the mods done ive mentioned, the thing runs incredible. wow is all i can say. put 205 miles on it saturday at the stampede

Hey Joe,
This is Michael. I met you down at Links 2 weeks ago and I have the 2010 450 EXC. It sounds like we are doing the exact same things to our bikes at nearly the same time. I spent last night ripping all this stuff off my bike using these exact pictures and another couple links I found. After doing this I also changed the idle jet to the JD kit. The bike is running remarkably better now.

My understanding is that, you can remove all the stuff completely if you want, but by leaving it on the bike it makes it easier to convert for use at places that require a catch can (and most likely for states that require inspections to be street legal). It's not air tight, so the bike should run the same either way. If you leave it on, make sure you pull the bolt out of the bottom or else you may be filling it with fuel often. It also may help to keep the hoses somewhat organized.

I went ahead and removed the catch can because it interfered slightly with my new skid plate. The Flatland Racing skid plate uses the same 2 bolts as the catch can and I didn't feel I could get a solid enough mounting by leaving it in place. If you stick with the factory plastic skid plate then this wouldn't be a problem.

The cannister doesn't do much for performance either way, but I just bought 5 feet of hose and routed the gas cap vent to the bottom of the bike near the carb vent hoses. This bypassed the cannister and I went ahead and yanked it off the bike also.

I think the second link you posted is actually the wrong one. This picture shows one of the carb vents, not the crankcase and I believe you don't want to mess with that one. I believe the t-connector that you actually want is the crank case vent which is on the other side of the engine from the choke. You probably had to remove it when you were doing the JDJet kit. It's a bigger tube. It comes out of the crankcase and then goes back to the carb and down to the bottom of the bike. My understanding is that some people will remove the T and the hose that runs to the carb. They will replace it with a single tube that runs to the bottom of the bike so that it keeps extra oil out of the carb. From what I've heard, this can lead to problems if you are running your bike in places where it can suck up water and such. Racers doing it on closed course because they don't want to have the engine run poorly for a short period after a bad getoff during a race, but I personally don't care about this.

Here is a link to some company that sells a kit to reroute the crankcase vent hose. I didn't buy the kit, nor do I know anything about the company but it shows what is necessary if you really wanted to do it. http://blaisracingservices.com/index.ph ... ductId=692

Not sure whether any of this helps or not and hopefully somebody else will chime in if any of this is incorrect.

Also, I used this link as a guide and adapted it for the newer bikes. Most things are very similar.
http://www.advrider.com/forums/showthread.php?t=176776

Hey 'nut, you didn't roost anyone on a KLR at the Stampede did ya? That would be irresponsible......

-Harvey
#713

hey michael, thanks for the info. i emailed safiri and he sent along some good info too. im heading out to remove the canister now!



hey TF, you shoulda come along. our little stampede group had just 3 riders! 130 riders showed up but no-one wanted to ride with dano!! since his klr was the leader of our little pack, he didnt get roosted at all. cant say as much for the poor 650L that was riding sweep. i think he has a new apprectiation for the might 530's power! 230 miles on it now and the rear tire is shot. you think it was spinning at all that day?~!

xr-nut wrote:hey michael, thanks for the info. i emailed safiri and he sent along some good info too. im heading out to remove the canister now!

If Safiri sent anything that you think would be useful to me would you mind forwarding it along. I was hoping that if I had posted anything that was too incorrect that somebody would correct me before I blew up my bike

reddof wrote:

xr-nut wrote:hey michael, thanks for the info. i emailed safiri and he sent along some good info too. im heading out to remove the canister now!

If Safiri sent anything that you think would be useful to me would you mind forwarding it along. I was hoping that if I had posted anything that was too incorrect that somebody would correct me before I blew up my bike

Did you get a new battery yet????

HM-are you asking me if i got a new battery or reddof?! after putting 205 miles on it saturday and getting the carb dialed in, it starts with one push of the button. no choke. hit the button and its running. i think this motor was really tight and just needed a few heat cycles and miles to loosen it up. the clutch is better now also.

reddof- here is the jist of what safiri offered, i did the carb vent mod but im leaving the crankcase breather-as i plan to submerse this in DEEEEEP water!

safiri says-"This is what I know about the RFS (<2008) engine:
1. The vent from the crankcase needs to go to the carb. MX racers will route this hose to the atmosphere. Problem is that if you go in water, it will suck water into the crankcase, right onto the counterbalancer bearing. The breather nipple on the RFS is in this pic, lower left of carb: http://www.pbase.com/jdjetting1/image/87669959 The RFS only has one breather hose. The carb provides vacuum to keep the crank under vacuum.

2. The FCR carb has four breather hoses coming off of it. Two each from two T's. These allow the float bowl to breathe and not be under vacuum. Plug them up (say in a deep water crossing) and the engine will starve for fuel and die (or get rich and die ...). You can mimic this with a cup of water. My understanding is no water gets pulled into carb. Fix for this is to take one hose from each T and route up and over frame into airbox. There is a chance that on a fall fuel will leak into airbox, but the risk of fire is minimal. The hoses are also in the same pic: http://www.pbase.com/jdjetting1/image/87669959.

Here are writeups:
http://ktmtalk.com/index.php?showtopic=171578
http://ktmtalk.com/index.php?showtopic=171766"

so all done-ive added a scotts damper, removed all the street stuff(horn, t/s's, mirrors, etc-as ive already broken a t/s!) took off all the hoses-cans-valves except mentioned above, jdjett kit, exhaust tip mod. it runs really strong now. its time to ride it!

Hank Moody wrote:Did you get a new battery yet????

I'm going to grab the battery as soon as more funds are available (7/1). I'm not planning any more rides (further away than my backyard at least) until then anyway.

It is running even better after the last set of modifications I did on Monday night. I think the idle jet was the last step. I hadn't change it earlier because I still had all the emissions stuff in place. It is starting a little easier, but I still don't trust this battery.

xr-nut wrote:reddof- here is the jist of what safiri offered, i did the carb vent mod but im leaving the crankcase breather-as i plan to submerse this in DEEEEEP water!

I assumed I would hit deep enough water at some point that I didn't want to leave it disconnected either. I can't imagine it'll make that much difference and the bike has enough power for now.

xr-nut wrote:

safiri wrote:2. The FCR carb has four breather hoses coming off of it. Two each from two T's. These allow the float bowl to breathe and not be under vacuum. Plug them up (say in a deep water crossing) and the engine will starve for fuel and die (or get rich and die ...). You can mimic this with a cup of water. My understanding is no water gets pulled into carb. Fix for this is to take one hose from each T and route up and over frame into airbox. There is a chance that on a fall fuel will leak into airbox, but the risk of fire is minimal. The hoses are also in the same pic:

Well as long as it's minimal, that's good enough for me. I might reroute those hoses. I'll take a look and see what the odds of getting them plugged and how quickly the bike dies if they do.

xr-nut wrote:so all done-ive added a scotts damper, removed all the street stuff(horn, t/s's, mirrors, etc-as ive already broken a t/s!) took off all the hoses-cans-valves except mentioned above, jdjett kit, exhaust tip mod. it runs really strong now. its time to ride it!

I haven't changed the exhaust tip yet but have it planned. I've done everything except the damper (which I'd like at some point). I did swap out the 15:45 sprockets for 14:52 which I would recommend. Very happy with all the changes. They have made an incredible difference.

hey reddof, one last thing i failed to mention is to turn your idle up. almost to the point were you think its too fast. that will keep it from stalling as easily in the woods and at initial take off(starting from a stop).

xr-nut wrote:hey reddof, one last thing i failed to mention is to turn your idle up. almost to the point were you think its too fast. that will keep it from stalling as easily in the woods and at initial take off(starting from a stop).

This seems to be a common problem with the KTM owners (and perhaps other brand owners?) ... a low idle will cause the front end to dive among other problems. Further, you have a single cylinder providing power with a relatively small flywheel so you need some revs to keep the motor running. The gurus at KTM Talk write that the auto decompressor will start clacking around 1200- 1500 rpm. So you want to be a bit above that. A tachometer would be nice to at least hear what 1800 rpm (RFS idle speed, not sure about the newer motors) sounds like.

Here is a link to another write up of how and where to route your carb vent hoses.
Where can you buy one of those T fittings? I'm assuming an auto parts store???

http://www.thumpertalk.com/forum/showpo ... stcount=19

Hank Moody wrote:Here is a link to another write up of how and where to route your carb vent hoses.
Where can you buy one of those T fittings? I'm assuming an auto parts store???

http://www.thumpertalk.com/forum/showpo ... stcount=19

They way KTMTalk guru DJH suggests: http://ktmtalk.com/index.php?showtopic=171578 (No T required)

You can get a T at the auto parts store or probably at Lowe's or Home Depot in one of those drawers in the hardware section.

safiri wrote:

Hank Moody wrote:Here is a link to another write up of how and where to route your carb vent hoses.
Where can you buy one of those T fittings? I'm assuming an auto parts store???

http://www.thumpertalk.com/forum/showpo ... stcount=19

They way KTMTalk guru DJH suggests: http://ktmtalk.com/index.php?showtopic=171578 (No T required)

You can get a T at the auto parts store or probably at Lowe's or Home Depot in one of those drawers in the hardware section.

I will try without the "T" first and let you all know if one is needed.

I think DJH is Dave Hopkins from McGoodies.com and here is a video of him doing a valve adjust on RFS motor.

http://www.youtube.com/watch?v=hWS9RuEQzc8

This thread just got resurected over on KTMTalk: http://ktmtalk.com/index.php?showtopic=348610&st=0

Hank Moody wrote:Here is a link to another write up of how and where to route your carb vent hoses.
Where can you buy one of those T fittings? I'm assuming an auto parts store???

http://www.thumpertalk.com/forum/showpo ... stcount=19

Well I did the re-routing of the hoses and it is VERY easy. No "T" is required, just a couple zip ties to hold the tubes in place. Everyone should check your carb hoses because I had 2 melted hoses! You know, sorting out all the problems from the previous owner