1200 Interstate (1984) - mixture setting HOW ?


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Bambosz
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1200 Interstate (1984) - mixture setting HOW ?

Post by Bambosz »



Guys,

got little problem ;/
After all work on my honda, my spark plugs are ... white ;(
Know it's mean I got not enought fuel in my mixture. Question is, how can I change fuel mixture ?
As I know my carbs does not have "mixturescrew" - mean I remove one of those "plugs" on carbs, where could be screw (in manual they say that it is hidden because of some exhaust rules, etc ...).
But problem is, I dont have any screws there - only a looooong hole to next carb :/.

And here is my question.
How can i change fuel mixture
and
is there any chance that it was changed during carb synchronization ?
(is it possible to change something during carb synch. that could change my mixture) ?
If so ... how can I"repair" it ?

PS. for what is, and where is located "pilot screw" in Interstate 1984 ?
Is it only for iddle (mean rpm on neutral) ?

It's hard to translate everything correctly into polish :/



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virgilmobile
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by virgilmobile »

All white plugs is a complete lean fuel mixture from all carbs.Idle mixture screw will not fix this.
A lean mixture may be caused by the floats set too low..even a few millimeters will affect the fuel to air ratio.
All the vacuum slides could be stuck or the diaphragms bad.They must operate as they meter the fuel delivery above a idle.
There may also be a vacuum leak at the carb mounts.

Bambosz
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by Bambosz »

Thanks for answer.

Fuel floats are set at 7,5 mm (I'll check all during fuel value replacement), like manual says.
Carb put on his back, floats gently put down ... and its 7,5 mm from "gasket" to end of float.

Vacum Slides - mean those black "rubber" inside carb, which hold needle ?
Those are ok. Cant believe all could be bad at the same time - same with carb mounts :/

It's strange, because on "old" spark plugs all was good - those were like a "light coffe", one was black (wherever I put it), this why i change all ;)
Now I bouht four new one (made 100 km on new ones) the same numbers (like manual says) ... and they are white O_O.
I've didn't change anything with fuel, air ... didn't even change air filter.

And I feel when trying to accelerate that engine is "shaking" (over 3000 rpm), just like not enought fuel or air (in that situation suppose fuel ;D)
Asking because I made synchronization by myself (with vacuometer), and I thought I could change something to much or something ...
And now I'm looking for any option to make mixture richer. There must be something what regulate fuel quantity ...

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virgilmobile
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by virgilmobile »

A hundred km may not be enough to get a accurate "plug reading".
If you think its lean at 3000rpm,add about 1/4 choke during the shaking.If it smooths out you confirm a lean condition.
My 1200 was lean in that rpm range also.I just lifted the needles a bit with a washer to enrichen it a bit.There's a post about this problem.

Bambosz
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by Bambosz »

virgilmobile thanks for answer, I'll try it ... when it stop raining :/

Now need to search for that "needel change" (suppose need to move it higher somehow) ... ;)

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virgilmobile
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by virgilmobile »


Bambosz
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by Bambosz »

Hah, I found it today ;D

As I see you put that pad "under" needel head and "over" Vacum Slides(15) "floor".
Did you change anything in that little plastic(yellow) "cap (nut)" (10) which hold needel at the bottom of vacum slider ?

Oh, and there is photo described as "drilled the pilot cap"
It's that cap just below curberator pipe going to cylinder ?
Mean it's idle screw there ?
Got it opened and found another "cap" (just under 14) on carbs but on top. It's ... highest pipe on those three pipes(1) on image
http://www.cmsnl.com/honda-gl1200i-gold ... ml#results

Will try first check that 1/4 choke if it help, I'll put something "under/over" needle.

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virgilmobile
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82 GL1100 I
83 GL1100 I
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84 GL 1200 I

Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by virgilmobile »

Don't drill out the upper caps.there just plugs.
Nothing else was added at the needle under the retainer cap.
All 4 of my idle adjustment screws are on the edge of the bowl, inline with the idle port at the throttle opening.
By all means,do add a bit of choke when its stumbling to verify if its lean.Resync the carbs after install.

Bambosz
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Joined: Sat Nov 26, 2016 11:40 am
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Re: 1200 Interstate (1984) - mixture setting HOW ?

Post by Bambosz »

I was thinking about that:


Put pad (red line) between needle (yellow) and vaum slider (gray).
This move needle "up".

Everything will be clear after that "choke" test ;p



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