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carbed at mile high?

Started by beater, July 28, 2008, 04:36:23 PM

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beater

ok - disclaimer. I am not new to denver, or carbs, but I am new to running fcr's on the street. I searched here, and other (ahem) forums, to no avail for reference points.

my seat of the pants dyno feels sluggish from 4k wot. I just want to see what other carbies are doing at this altitude...

my settings/config:
41mm fcr's with 1.75 on air screw, 5/8ths or so fuel screw, 158 main, emt needle on 4th down. air jet 200, slow 60

bike: hi-comps, dyna's, accel wires, open airbox, 50mm dp pipes, stock header, stock ignition modules.

Mines  a 900ss, but I would think any 2v 900 would be relative.


tia
j

flynbulldog

This thread is funny!        ...A technical question       ...about bikes       ...on the MHM forum!!!!


[laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh]

Randimus Maximus

You know, I was just up at Boulder Motorsports the other day and they mentioned they had been seeing a lot of carbed ducs lately.  Perhaps they could give some baselines?

Manny

These folks would be good to ask:
the DMF Tech Board

And this discussion seems somewhat similar to your issue. Most of the fixes mentioned here will be good places to start.

Bick

Quote from: Randimus Maximus on July 28, 2008, 04:56:21 PM
You know, I was just up at Boulder Motorsports the other day and they mentioned they had been seeing a lot of carbed ducs lately.  Perhaps they could give some baselines?

Or Arapahoes.  Baseline is a little further south.   [laugh]

Seriously, that's who I would call.
It's all in the grind, Sizemore. Can't be too fine, can't be too coarse. This, my friend, is a science. I mean you're looking at the guy that believed all the commercials. You know, about the "be all you can be." I made coffee through Desert Storm. I made coffee through Panama while everyone else got to fight, got to be a Ranger.

* A man can never have too much whiskey, too many books, or too much ammunition *

Manny

Quote from: Bick on July 28, 2008, 05:20:30 PM
Or Arapahoes.  Baseline is a little further south.   [laugh]

Seriously, that's who I would call.

Smart-ass. You'll give us all a bad name...  [cheeky]

BMS is good. Faster/TK is also good. Between those two it may come down to scheduling or price for you.

flynbulldog

#6
 [thumbsup] [thumbsup] [thumbsup]

see what I mean...  Most of us don't know what an FCR is, but we can tell you who to take it to.  [laugh]

On second thought most shops don't like to tune carbs any more either, they can't do it with a laptop  [cheeky]

flynbulldog

Just general carb logic would dictate sluggish above 4K = rich mains.

Stumbling or dead spots would indicated lean.

Sorry, not spoken from experience but it's a place to start.

beater

Quote from: flynbulldog on July 28, 2008, 04:52:34 PM
This thread is funny!        ...A technical question       ...about bikes       ...on the MHM forum!!!!


[laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh] [laugh]

forgive my breach of etiquette.  I posted here, as there are very few places that are at 5k feet here in the us, or abroad for that matter, that might actually have people that work on their own rides.... I have learned my lesson.

I will take it to a dyno once I get it close enough. oh, and fcr's really aren't about rpm, more about throttle position. They are a pumper carb.


beater