Author Topic: jetting for 7000 feet?  (Read 2165 times)

superstockfl350r

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jetting for 7000 feet?
« on: June 08, 2013, 11:49:20 PM »
Hello there,
I am new to this forum and am really enjoying all of the great information and input. I just finished my build with a makuni 40mm carb, v force3 reeds, wiseco piston etc.. anyways I just moved from phoenix az 1200 feet elevation to flagstaff az which is 7000 feet in elevation. I ran it today and it seemed to be doing just fine however I dont want to run it lean and burn something up. I have a full set of jets but am unsure what I should use for my new elevation. Does anyone have any ideas for me on fine tuning my jet set up for my extreme elevation. Will post pictures tomorrow when its light.Cheers

odypilots

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Re: jetting for 7000 feet?
« Reply #1 on: June 09, 2013, 07:04:10 AM »
Without an EGT, I've found it safest to jet down from rich. When I first started, I found out it's not safe to base my jetting on my friend's jet size, even though both were pure stock. Try your biggest jet, and then get bigger ones if it runs clean.
The usual 'my two cents' disclaimer applies. :)

superstockfl350r

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Re: jetting for 7000 feet?
« Reply #2 on: June 09, 2013, 07:56:30 AM »
I have a digitron with the egt readout etc.. what are the ideal operating temps when jetted correctly? I will run her today to see where my temps are. I have never been up this high in elevation so I am not sure how it will effect the burn temps. Also what are ideal head temps when hot? I dont have the water cooled head yet but I do have a pro-jet fan mounted and wired for extra cooling help. Any information I can get would be great..Cheers.. Pics to come.

odypilots

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Re: jetting for 7000 feet?
« Reply #3 on: June 09, 2013, 10:58:52 AM »
I've always used 1150-1200 degrees as my safe temps, but probe placement also affects those numbers, so it's best to do spark plug checks to find each machine's egt's safe zone. I can exceed those temps for a few seconds. I've never monitored head temps so have no data for you there. If she's running crisp and clean, be wary.
The usual 'my two cents' disclaimer applies. :)

superstockfl350r

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Re: jetting for 7000 feet?
« Reply #4 on: June 09, 2013, 12:28:11 PM »
Thanks for the input. I will run her today to see how the temps are doing. Here are some photos of her. She was completely torn down and rebuilt with brand new equipment. New fl350 case and head boared over stock. Wiseco internals. Engine built by specialty shop in phx az. All brand new stock suspension that I had laying around in boxes. (Waiting on my front and rear WORKS so these will be for sale soon. As I said brand new) I did a custom diamond plate tub, sides, air channels and expanded steel nerf covers all ribbed with edge housing. The rear fender sections are fabbed out of sheet titanium alloy. I am also waiting on douglas wheels with 23" front and rear kenda bear claw tires. The pro-jet fan and all lights are poperated by toggle switch box fabbed next to the ebrake. All new brakes including rear caliper and disc. I am looking into a front disc conversion so the fronts will be available for sale as well.(Total of 1 hour run time on full front set up) she is fast and fun. Also looking into an original Randy watercooled head set up.

shoubadaba

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Re: jetting for 7000 feet?
« Reply #5 on: June 09, 2013, 09:39:36 PM »
I saw this machine forsale a few months back on craigslist did you just purchase it? Going from 1200 feet to 7000 feet you will be running richer so you will need to down jet.

odypilots

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Re: jetting for 7000 feet?
« Reply #6 on: June 11, 2013, 12:29:59 PM »
I saw this machine forsale a few months back on craigslist did you just purchase it? Going from 1200 feet to 7000 feet you will be running richer so you will need to down jet.

shoubadaba is right. Higher altitude means thinner air, so less fuel (smaller jet) is required, not more.
The usual 'my two cents' disclaimer applies. :)

superstockfl350r

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Re: jetting for 7000 feet?
« Reply #7 on: June 13, 2013, 12:09:37 PM »
No I just decided to keep it. Was planning on getting a couple pilots out of Vegas but the deal fell through and we moved to Flagstaff. Got my Works Tuesday. Excited to go ride this weekend.