Stumbling between 2-3k rpm


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AJELLIS12
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Stumbling between 2-3k rpm

Post by AJELLIS12 »



Hello I'm new to Goldwings and this forum and am having issues getting my wing to run right. I have installed the updated jet kit per the service bulletin and still have a flat spot in the throttle between 2000-3000 rpm. It's more so when cold but does still do it when hot too. I'm wondering if since it seems that it's at the beginning of the throttle opening if I need to back the fuel screws out more.



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virgilmobile
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Re: Stumbling between 2-3k rpm

Post by virgilmobile »

If you can feather the throttle to where it stumbles..add just a bit of "choke" to it.Maybe 1/4 or so..See if it smooths out.
Mine did..Had to lift the main needle jet a few mm to get it through the lean spot.

AJELLIS12
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Re: Stumbling between 2-3k rpm

Post by AJELLIS12 »

virgilmobile wrote:
Wed Jul 17, 2019 7:30 pm
If you can feather the throttle to where it stumbles..add just a bit of "choke" to it.Maybe 1/4 or so..See if it smooths out.
Mine did..Had to lift the main needle jet a few mm to get it through the lean spot.
I have one spacer under the needle currently should I add another or thicker one?

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virgilmobile
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Re: Stumbling between 2-3k rpm

Post by virgilmobile »

Only if adding the ckoke helped

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virgilmobile
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Re: Stumbling between 2-3k rpm

Post by virgilmobile »

And also that you have verified that the slides move properly and the diaphragms are perfect(no holes).
Lifting the needle adds just a touch more fuel in that rpm range

AJELLIS12
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Re: Stumbling between 2-3k rpm

Post by AJELLIS12 »

virgilmobile wrote:
Thu Jul 18, 2019 5:00 pm
And also that you have verified that the slides move properly and the diaphragms are perfect(no holes).
Lifting the needle adds just a touch more fuel in that rpm range
what's the best way to check the slides? When I had the carbs apart the diaphragms looked ok i don't know if they are sealing perfectly or not as I found it hard to keep them in the groove while putting the caps back on.

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Re: Stumbling between 2-3k rpm

Post by ride dont hide »

AJELLIS12 wrote:
Sun Jul 21, 2019 2:50 pm
virgilmobile wrote:
Thu Jul 18, 2019 5:00 pm
And also that you have verified that the slides move properly and the diaphragms are perfect(no holes).
Lifting the needle adds just a touch more fuel in that rpm range
what's the best way to check the slides? When I had the carbs apart the diaphragms looked ok i don't know if they are sealing perfectly or not as I found it hard to keep them in the groove while putting the caps back on.
Try this little trick when re-assembling slides: invert rubber diaphragm forming a "mushroom" on top of the slide. Put your finger in the carb throat and insert slide. You can hold the slide in the perfect position with the diaphragm fitting nicely in the groove while you install the spring and cap. No more guessing of it is in the correct position!

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virgilmobile
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Re: Stumbling between 2-3k rpm

Post by virgilmobile »

I use a shop vac.Attach to each carb one at a time and operate the throttle.The air flow changes as you operate the throttle and should lift each slide about half way up.
The shop vac simulates a cylinder running.

AJELLIS12
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Re: Stumbling between 2-3k rpm

Post by AJELLIS12 »

So i tried adding choke and it doesn't seem to make any difference. seems like it's getting worse at times. runs like a champ above 3000 rpm. its much worse when cold then hot.

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Re: Stumbling between 2-3k rpm

Post by AJELLIS12 »

virgilmobile wrote:
Sun Jul 21, 2019 5:08 pm
I use a shop vac.Attach to each carb one at a time and operate the throttle.The air flow changes as you operate the throttle and should lift each slide about half way up.
The shop vac simulates a cylinder running.
So I did your shop vac trick after removing all the slides and cleaning up the bores and slides with 2000 grit sandpaper the work butter smooth now, I also found a vacuum line that had a tear so I replaced all vac lines including the emission hoses under the carbs. Took it out for a test drive and still has a hesitation. Im beyond frustrated at this point as I have tried everything that I can think of as a mechanic for over 20yrs.

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virgilmobile
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Re: Stumbling between 2-3k rpm

Post by virgilmobile »

Hmmm.No improvement with added choke...so there's enough fuel...
Worse when it's cold...
Have you used a unlit propane torch to see if there's a vacuum leak?Especially at the carb rubbers.

AJELLIS12
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Re: Stumbling between 2-3k rpm

Post by AJELLIS12 »

So an update I found that the aftermarket fuel pump and coils I purchased were junk after I replaced them and the fuel filter it runs I believe as it should. I also gave it a quick sync just to be certain. Thanks for all the help.



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