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Slide needle adjustment at 5000Feet

Fuel System: Gas (Petrol) tanks, Carburators
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jcspc
honda305.com Member
Posts: 65
Joined: Sat Feb 09, 2008 8:50 pm
Location: Bozeman, MT

Slide needle adjustment at 5000Feet

Post by jcspc » Sat Jun 14, 2008 6:08 pm

Hello
I just reinstalled my motor after a top end rebuild. During the rebuild process I tore the carbs down and rebuilt them. So as I was going thru the settings stuff in Silvers book it occurred to me that maybe some of the carb adjustments may be different at 5000 feet. The bike came from here and I didn't notice the air screw setting when I removed it and the slide needle is set at the top slot.
Should I stick with Silver's recommendations or leave the needle where its at?
jcspc

jesmed
honda305.com Member
Posts: 79
Joined: Tue Jun 14, 2005 4:53 pm
Location: Cambridge, MA

Post by jesmed » Mon Jun 16, 2008 8:23 pm

You'll probably need different main jets and needle jet settings at 5000 ft than you would at sea level. But since you say the needle jet clips are in the top notch, previous owner may already have properly adjusted for altitude (at sea level, correct position is 3rd from top if I remember). Best way to tell how you're running is to pull the plugs and check the tips. The main thing you want to avoid is running lean (very clean plug tips), which can lead to melting a piston. If you're jetted correctly you'll be getting a bit of brown/black carbon deposit on your plug tips, but not so much that they foul.

jcspc
honda305.com Member
Posts: 65
Joined: Sat Feb 09, 2008 8:50 pm
Location: Bozeman, MT

Post by jcspc » Mon Jun 16, 2008 11:18 pm

Thanks for the tip. Ya know, I had the carbs completely torn down and I forgot to check the jet sizes when I had them out. Now I really hope that the jets are proper for this altitude cause the theads are most likely J.I.S. and I got a feeling there's not alot of those around! I'll pull the carbs and check the numbers. By the way, its a 65' CL77.

jcspc

jesmed
honda305.com Member
Posts: 79
Joined: Tue Jun 14, 2005 4:53 pm
Location: Cambridge, MA

Post by jesmed » Tue Jun 17, 2008 10:36 am

No worries; main jets are still readily available, possibly from your local Honda dealer. If not, you can order them from www.westernhillshonda.net. (By the way, you should be able to remove the main jets without pulling the carbs off. Just remove the bowls and use a short screwdriver to unscrew the main jets.)

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