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Will be riding in the mountains and will likely need to change out jets for the over 8000ft rides. Anyone else done this and refers to a how to video? KTM 450 EXC 2005.

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you can change the main and the pilot without removing the bowl, just take off the large drain bolt on the bowl. You may not be able to actually get in there to take out the jets without removing the carb, but maybe can do it by rotating carb. Its easier if you remove the tank to get ot it and see it all. You may want to lower the needle a notch too. Now, you may find that your 450 will run OK, not great, at that elevation by not changing the jets. Turn the fuel screw in to reduce the pilot jet type flow and you may be satisfied.

Edited by Mike in Fresno

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So let me see if I understand this because I'm going to higher elevation where there's less oxygen, I need smaller jets that provide less fuel to go with less oxygen so the engine does not flood, correct?

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I will see how I do without the jet change. I have some extras I got with the bike just in case. I know the carb can be turned to access the bowl. I have an adjustment knob for fuel air mixture. If it starts to sputter I will try that first.

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Here in California we have some big hills but riding over 7500 feet is rare. I used to suck it up when it started to burble at altitude. After a couple week long trips to Colorado and hitting 12,000 feet daily I was glad I had a JD jet kit and the jetting chart. It was spot on.

My daughters CR150R is an absolute nightmare to jet and I still can't get it run correctly past 10,000 feet. It is OK just rolling along on single track but get into rocks and start working the throttle and all you do is kickstart it.

Spend the 75 bucks on a jetting kit and enjoy your bike running well.

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Good point. I need to figure out what size jets to use, I have several. I wonder if the chart you speak of is available on-line?

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Order Klotz nitro. You can add nitro to your gas and not have to touch your carb, you'll have sea level power at 12,000 ft. The more you add the leaner it will run. I was riding at 90000 to 13000 ft and added 4 oz per gallon and my 06 ktm 450 exc ran strong. Used it in my old Suzy rmx250 before the ktm and it ran great. U can talk to the Klotz tech guy if u have questions

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Good point. I need to figure out what size jets to use, I have several. I wonder if the chart you speak of is available on-line?

 

The JD Racing kit is not just jets, the kit is based on using 1 of the 2 needles supplied in the kit. It's really the needles that are key to his jetting, using his chart with other needles will just screw you up as they are interdependent.

 

Bruce

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The JD Racing kit is not just jets, the kit is based on using 1 of the 2 needles supplied in the kit. It's really the needles that are key to his jetting, using his chart with other needles will just screw you up as they are interdependent.

 

Bruce

Yes you absolutely need to run the complete JD jet kit and follow the chart. Once you set it up with the pump spacer, oring and correct needle you really only need to roll the carb over to the right and swap jets from the bottom. Piece of cake.

I bought my bike with 73 miles on it. The guy did not like it. It came with a JD kit which he said he installed. Turns out all he did was swap the main. No wonder he didn't like the way it ran. Once I dug in and set it up correctly it ran like a raped ape and doesn't get hot.

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Order Klotz nitro. You can add nitro to your gas and not have to touch your carb, you'll have sea level power at 12,000 ft. The more you add the leaner it will run. I was riding at 90000 to 13000 ft and added 4 oz per gallon and my 06 ktm 450 exc ran strong. Used it in my old Suzy rmx250 before the ktm and it ran great. U can talk to the Klotz tech guy if u have questions

Are there any risks to the engine using Nitro? Sounds like a great idea, and much less trouble than a jet change for my very short term need!

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Yes you absolutely need to run the complete JD jet kit and follow the chart. Once you set it up with the pump spacer, oring and correct needle you really only need to roll the carb over to the right and swap jets from the bottom. Piece of cake.

I bought my bike with 73 miles on it. The guy did not like it. It came with a JD kit which he said he installed. Turns out all he did was swap the main. No wonder he didn't like the way it ran. Once I dug in and set it up correctly it ran like a raped ape and doesn't get hot.

Good to know. Thanks! Can't say I have seen a raped ape run, but I bet your bike would be faster! ;-)

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I ran nitro 5 trips to Colorado in all our bikes. 2 two strokes, 3 - 4 strokes for 6 days in a row each trip. I went with 4 oz per gallon because they ran the best that high up. The lower the alt. the less you use. I think 4oz per gallon was max u can use. One friend wanted to run his bike by just jetting and we were blowing him away. He put the stock jetting back in and ran nitro. Niro is like liquid oxygen. It worked great for us. Didn't even touch the idle adj. u just have to remember to drain the fuel when u get home because the bike would run really lean. Klotz shipped nitro last time we were up there when I ran low.

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doesnt nitro collect moisture like alcohol and then leads to corrosion? Need to run an after run oil to keep the inside rust free?

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doesnt nitro collect moisture like alcohol and then leads to corrosion? Need to run an after run oil to keep the inside rust free?

I need to research this.  Certainly do not want to risk damaging the bike for convenience alone!

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What corrosion could u be worried about. Your tank is plastic. Carb aluminum or pot metal. R u just going on a trip or is all the riding you'll be doing at high alt. I have to check the nitro can and see how much u need at 8000 ft. We started at 9000 and we were using 4oz per Gallon. I think 1oz per gallon is 1 jet size leaner. I'll check tomorrow I keep forgetting to look. Ok!!

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