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CV40 jet sizes

Started by 1340evo, February 18, 2021, 10:23:56 AM

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1340evo and 2 Guests are viewing this topic.

1340evo

Quote from: HD Street Performance on March 06, 2021, 06:44:48 AM

Select a convenient mounting location for the Bosch sensor. In general, the sensor should be mounted as close to the exhaust valve or exhaust manifold as practical. When choosing a mounting location, allow several inches clearance for the sensor wire harness. The wire harness must exit
straight out from the sensor


interesting... some info I was reading said 24". I've not actualy opened the box as yet as its at work and I'm at home. Will have a read Monday ;)

HD Street Performance

I can understand that advise as it relates to cars especially with a closed exhaust system

1340evo

Are you guy's using a 12mm sensor or 18mm?

Looking at a 18mm sensor, it will block off a lot of the exhaust....

But can you get 12mm wideband units?

JW113

24" on a bike exhaust is way too far back. Mine is maybe 7" from the exhaust port, and only because any closer there is no access. I have the Bosch sensor, 18mm, same as a spark plug.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

okay, just looks big for the pipe... would of thought most bike application would be the 12mm if they do wide band....

Burnout

Use a long bung when mounting an O2 in a header pipe so the sensor does not mess with flow.

If you put it in a larger pipe there is less of an issue, but in a runner you don't want the sensor blocking flow.
They don't call me Ironhead Rick just because I'm "hard headed"

1340evo

September 04, 2021, 11:29:34 AM #56 Last Edit: September 04, 2021, 01:24:20 PM by 1340evo
Okay, with the engine close to run in, I've just changed my jets.
It was kind of thumpy every time it fired so I'm thinking over fueling a tad. I was at 46 / 185 so I've dropped back to 45 / 180 and its so much better. picks up better and not as harsh. I've kept the sporty needle.
So next as I can open her up a bit now is to get the AFR meter on it and see how it looks.
Seat of pant tho, its much better at the lower jets :)  and the plugs are starting to look better (only 10 miles on them at the new settings)


1340evo

Well. Its got cold here in the UK and over the weekend it was 4 deg. I took the bike out and it kind of didn't go as well as I expected, like its running rich (does that add up?.. Lots of thick cold air now where as summer I guess its thinner and hotter?
It does pop on over-run with the V&H pipes but it coughed back through the carb a couple of times also, something its not done before.

wfolarry

How does it run with the choke on? That can give you some indication if it's rich/lean.

Deye76

"like its running rich (does that add up?.."

Cold air is denser than warm air generally creating a lean condition.
East Tenn.
2014 CVO RK, 2015 RGS, 1992 FXRP

1340evo

so the colder it get's, the leaner it gets?...  are you sure?

HD Street Performance

Every mild CV40 EVO I had back in the day would run well with a 45 pilot, up from stock 42.

Deye76

November 22, 2021, 10:26:37 AM #62 Last Edit: November 22, 2021, 10:48:28 AM by Deye76
Quote from: 1340evo on November 22, 2021, 07:58:24 AMso the colder it get's, the leaner it gets?...  are you sure?

Only things I'm sure of is taxes and death.
Google it, or ask a dyno tuner.

Your earlier post,............ "So next as I can open her up a bit now is to get the AFR meter on it and see how it looks."
What does your AFR gauge show?
The S&S on my FXR runs leaner when it's colder out, fuel consumption is 4 mpg better when it's 40 deg. F.
East Tenn.
2014 CVO RK, 2015 RGS, 1992 FXRP

kd

Quote from: 1340evo on November 22, 2021, 07:58:24 AMso the colder it get's, the leaner it gets?...  are you sure?

Cold shrinks most things and that makes them denser by volume. The air flow is a constant determined by the throat size of the carb and throttle valve position.  The same volume of denser air equals more oxygen in the mix.  If the fuel remains metered at the same jet size that will mean the air fuel ratio tips over to more air but the same fuel.  The air / fuel ration is therefore leaner in cold weather.  A good example is having to use the choke longer in cold weather startups or the engine spits back through the carb (typical lean response).
KD

JW113

Every time I've popped one of those N65C ('88 sportster) needles in on of my bikes, I've taken it back out. EVERY time.

Just sayin'...

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

Yes, from how it was, I'd say lean for sure. What KD says is just what I experianced.
I never got it on the AFR meter this summer as the return spring went in the greabox so had to set about doing that with my limited time, but this does give me some idea its probably not far off. I've still to put 50 miles on it to finish running it in LOL

So what do people do who use their bikes summer and winter in the US as I'm sure the temp extreames are worst there than they are in the UK ?

Hossamania

As far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet. I do not lug the motor.
We learn from history that we do not learn from history

kd

November 23, 2021, 02:29:49 PM #67 Last Edit: November 23, 2021, 02:34:34 PM by kd
Quote from: Hossamania on November 23, 2021, 01:41:33 PMAs far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet.  I do not lug the motor.

This is important.  Most of the adverse reactions happen at low RPM when the intake isn't really flowing yet.
KD

Hossamania

Quote from: kd on November 23, 2021, 02:29:49 PM
Quote from: Hossamania on November 23, 2021, 01:41:33 PMAs far as my CV carbs riding in extreme cold and extreme heat, they have always done well once dialed in. No jetting changes made due to weather, I just ride it and it works well. Choke on a little longer in the cold, and an occasional cough in extreme cold (30°F) roll on when the motor isn't quite hot, but no real issues. Worked from near sea level to 11,000 feet.  I do not lug the motor.

This is important.  Most of the adverse reactions happen at low RPM when the intake isn't really flowing yet.

I should also have mentioned, the carb coughs so rarely that it completely surprises me when it happens.
We learn from history that we do not learn from history

kd

Air velocity is your friend.  :wink:
KD

JW113

What he said. (Hoss, that is) Pretty much sums up my experience with them to the T. Regarding temp extremes in the UK compared to the "USA" (very, very big place spanning many climactic zones), I think you need to be a little more specific. I went out for a lunch ride today in a T-shirt and vest. So, probably a wee bit warmer here than in the UK right now.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

1340evo

It was 3 deg C (37F) last week, but that said summer is typicaly 20 deg c or so (70F), so not that much differance.
It does run poor on the choke like just on the front cylinder, but it always has.take out the plugs the front will be darker, but the rear will be a bit black... I need to investigate this a bit more. But with the choke off, it runs good and the plugs are exactly the same...

Hossamania

Yesterday at 07:59:50 AM #72 Last Edit: Yesterday at 08:15:13 AM by Hossamania
Delete, new post to come.
We learn from history that we do not learn from history