GL1500 rough idle hard start fix


Information and questions on GL1500 Goldwings (1988-2000)
GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

GL1500 rough idle hard start fix

Post by GLRT »



I was just reminded of this little 1500 trick over the weekend. My buddy just got 93 which had the galloping rough idle and somewhat hard start that every 1500 I have owned had. I discovered years ago that pulling the air filter and plugging the air jets with toothpicks would even out the idle and improve starting. I did this on his and also cleaned the filter and it runs like a champ.

If you look into the air horns the air jet is the dark little tube usually black just break a toothpick in half and stick it in there and the idle will speed up and smooth out. (you can do this when running to verify or just cover the jets with your fingers)



User avatar
keithg64
Posts: 707
Joined: Thu May 21, 2009 9:47 pm
Location: Geneseo, IL
Motorcycle: 2007 Gl1800HPNA Blue
2000 GL1500 Pearl Coranado Blue -sold

Re: GL1500 rough idle hard start fix

Post by keithg64 »

Really? Seem's like your masking an issue.
It's not what you buy, it's what you build.

User avatar
ct1500
Posts: 1392
Joined: Wed Nov 10, 2010 8:09 pm
Location: Glastonbury,CT
Motorcycle: 1988 GL1500
Contact:

Re: GL1500 rough idle hard start fix

Post by ct1500 »

Your "fix" is guaranteed to increase fuel usage.

Please repair faults properly, I pity the real mechanic/next owner who would have to toss those carbs now because some backwards hack jammed wood into the air bleeds. :roll:
Local and need repair help with your 1500, Valkyrie or ST please click contact
Nothing leaves my shop till its' perfect
This is what I do

User avatar
dingdong
Posts: 3931
Joined: Thu Apr 08, 2010 8:35 am
Location: Oklahoma City
Motorcycle: 1976 gl1000
1993 gl1500A
2004 NRX1800 Rune SOLD

Re: GL1500 rough idle hard start fix

Post by dingdong »

You're pulling our leg! Right???

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

No this is a real fix. You have never heard of this trick? Yes if you have one of the older 2 barrel carb models this does fix the rough idle. I use wooden toothpicks as they stay put and can be removed easily.

User avatar
virgilmobile
Posts: 9080
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: GL1500 rough idle hard start fix

Post by virgilmobile »

All joking aside,I wonder what those air jets feed.???
Is it possible they lead into the slow speed circuit?...
Does plugging them simply enrich the slow speed (pilot) fuel delivery and not affect the main fuel system.???..
Kinda like opening the slow speed jet adjustment(pilot screw) a turn or two for the "idle down"adjustment.
My 88 didn't idle well until I spent over hour with a 2' long screwdriver between the front forks just trying to find them.
The "preset was too lean.Mine took a full 2 turns more to stabilize the idle.
This toothpick trick may work just fine to overcome such a problem..
Trust me...how many carbs have you guys gone through,preset the idle screws and called it good enough.
There adjustable for a reason.Its the last step after a carb/fuel system/sync job.


Be it far from me to talk bad about modifying a carb as mine is no where "by the book"...BUT it does run like it's suppose to.
Well...maybe just a touch rich but better than a sputtering lean engine.
The OEM design was just wrong (to meet EPA standards or some silly such thing)
I do understand regulations but sheesh....I want it to run right as long as the mileage isn't in the toilet..

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

The air jets only affect the low speed idle and do not alter the mid or upper ranges. Yes you can adjust the jets with a 12" long tool but it's almost impossible and limited to the amount. believe me the toothpick deal does work - next time you have the filter out just start the engine and cover the air bleeds with your finger, you will notice an immediate increase in idle and smooth as silk. It does richen the idle just a tad which also improves starting.

User avatar
Fatwing Chris
Posts: 770
Joined: Thu Oct 21, 2010 6:10 pm
Location: Ont.,Canada
Motorcycle: 2004 ABS Model Goldwing

Re: GL1500 rough idle hard start fix

Post by Fatwing Chris »

keithg64 wrote:Really? Seem's like your masking an issue.
My thoughts exactly.
If I'da known it would last this long,I'da taken better care of it.
Chris
Double Dark
Darkside # 1602

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

Well you can try other things but masking as you say is the fix and this fix was learned many years ago on the early 750 fours.
If you understand how these carbs work you would probably understand how it really works and that it is not a masking issue.
I'm a pro what do I know 8-)

User avatar
ct1500
Posts: 1392
Joined: Wed Nov 10, 2010 8:09 pm
Location: Glastonbury,CT
Motorcycle: 1988 GL1500
Contact:

Re: GL1500 rough idle hard start fix

Post by ct1500 »

GLRT wrote:Well you can try other things but masking as you say is the fix and this fix was learned many years ago on the early 750 fours.
If you understand how these carbs work you would probably understand how it really works and that it is not a masking issue.
I'm a pro what do I know 8-)
Apparently you forgot how to first check for faults whether it be vacuum leaks or carb troubles that might be causing this lean condition and are just too lazy to properly set mixture screws.
Local and need repair help with your 1500, Valkyrie or ST please click contact
Nothing leaves my shop till its' perfect
This is what I do

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

Not really as the idle adjust can only go so far and no it's not vacumn hoses etc as this a problem that exists from day one.
Not a big deal though if you wish to ignore good advice and put up with rough running then it's just your call. I am just offering years of advice is all. It's not a big deal really so don't sweat it 8-)

User avatar
joeincalif
Posts: 821
Joined: Sat Nov 22, 2014 10:39 am
Location: Fresno, Ca
Motorcycle: 1997 Gold Wing SE

Re: GL1500 rough idle hard start fix

Post by joeincalif »

Are there that many that are having problems with the 1500 carbs? I have owned 3 1500's a 92 that I put 108,000 miles on a 98 that I put about 50,000 miles on and my 97 that I only have 37,000 miles on and I have never had to touch or adjust a carb. But I guess if you have a problem this is an easy fix if it works.
Image
IF YOUR BORN ONCE YOU WILL DIE TWICE
IF YOUR BORN TWICE YOU WILL DIE ONCE

User avatar
Fatwing Chris
Posts: 770
Joined: Thu Oct 21, 2010 6:10 pm
Location: Ont.,Canada
Motorcycle: 2004 ABS Model Goldwing

Re: GL1500 rough idle hard start fix

Post by Fatwing Chris »

GLRT wrote:Well you can try other things but masking as you say is the fix and this fix was learned many years ago on the early 750 fours.
If you understand how these carbs work you would probably understand how it really works and that it is not a masking issue.
I'm a pro what do I know 8-)
Mine was an 89 which was supposed to be one of the worst years along with the 88 and I never had an issue with carbs.

BTW I've wrenched for a living for over 30 years and I'm pretty sure these can be fixed right without jambing wood into a carb.
If I'da known it would last this long,I'da taken better care of it.
Chris
Double Dark
Darkside # 1602

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

OK sorry for trying to correct a problem good luck with the stumbling idle and fixing it the "right way" 8-)

nothingbut2
Posts: 7
Joined: Sun Apr 25, 2010 6:35 pm
Location: el paso, texas
Motorcycle: 1984 GL1100I

Re: GL1500 rough idle hard start fix

Post by nothingbut2 »

GLRT wrote:OK sorry for trying to correct a problem good luck with the stumbling idle and fixing it the "right way" 8-)
I agree with the advice most folks who have posted. I'm currently on my fourth year on an 88 1500. Rode it all year last year in PA (to include snowy days) where I am currently working. Will ride it again this year. And now that it is getting colder, this bike is exhibiting the same cold weather running issues. I have rebuilt the carbs on many GLs, to include this one, and replaced melted vacuum and water lines on this particular bike. What a pain in the can repairing these 1500 carbs are. That being said; this bike is one of the worst bikes to keep running when it's cold outside and on initial start up. A lot of folks claim to know what's going on and then there are those that actually do. Ride in cold weather every day and reality becomes important. Sites like this help, but folks with closed minds waste space. The carbs on the 88 and 89 suck and they do contain a design flaw that affected off idle hesitation, surging, cold starting. Period (resulted in a recall that didn't fix the issue). Try turning left and all of a sudden your bike wants to stall. Gets your attention. Oversized jets helped the off idle issue, but affected gas mileage. I'll take it rather than the off idle crap. There are other fixes I have read about on this site that are quite interesting, but simple jet replacement did it for me. That being said, if you have an older GL and if there is no vacuum leak, choke seems to work, fuel pump works, you have decent spark and your head gasket isn't leaking coolant into any cylinder, it's ok to become an alchemist. And the "fixes" do work; and they work for the life of the bike. DOT and politics make their way into motorcycle emissions and we all suffer when it's time to trouble shoot and repair. Simple as that. So, trouble shoot accordingly to satisfy the naysayers and then engage in your trickery. Or ride around on a surging 1500, one that exhibits the pain in the can off idle hesitation and let me know how much fun you are having. That is assuming of course you get it started. Mine has a (choke) sweet spot at 30 degrees and another at 20 degrees. And of course, another at 10 degrees. Anything below 10 I keep a spare car battery in the right bag just in case. So for every guy out there who rides mostly in summer, thanks for your opinion, I'll try the tooth pick fix...

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

As the author of the toothpick fix I can attest it does work and is certainly worth a try. The improvement is immediate and if not simply remove the toothpicks and no harm no foul.
I have not had one GL1500 in my shop that did not idle poorly before this fix and not one that did not run perfectly after the fix.
And it's a freebee, worth a shot don't you think?

User avatar
dingdong
Posts: 3931
Joined: Thu Apr 08, 2010 8:35 am
Location: Oklahoma City
Motorcycle: 1976 gl1000
1993 gl1500A
2004 NRX1800 Rune SOLD

Re: GL1500 rough idle hard start fix

Post by dingdong »

I admit that I was and am skeptical of the toothpick fix. If it works then fine. However the assumption that all 1500s have an idle problem is another thing. I have owned one (93) for 7 years. It has no idle or off idle problem what so ever. I know and ride with a bunch of guys with 1500s that have no idle problems. Seems to me that if other 1500s (most in my experience) (excepting the 88/89) run perfectly when the carbs and vacuum lines are good then there is a solution that doesn't involve a toothpick. JMHO.

nothingbut2
Posts: 7
Joined: Sun Apr 25, 2010 6:35 pm
Location: el paso, texas
Motorcycle: 1984 GL1100I

Re: GL1500 rough idle hard start fix

Post by nothingbut2 »

GLRT wrote:As the author of the toothpick fix I can attest it does work and is certainly worth a try. The improvement is immediate and if not simply remove the toothpicks and no harm no foul.
I have not had one GL1500 in my shop that did not idle poorly before this fix and not one that did not run perfectly after the fix.
And it's a freebee, worth a shot don't you think?
I believe it is. As mentioned the 88 and 89 carbs are junk. And riding these beasts in winter, all winter require creative engineering. Folks who disagree simply don't ride year round in extreme weather. Thanks for the tip.

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

Most of the units I have worked on ar 91 through 96 and seem to have a lean idle issue. I have a 96 coming into the shop here in a few weeks and I will do a video showing the procedure and results as this can be done while the engine is running. It's that safe.
This really is the carb version of rechipping the ECM. Lot's of people do that all the time

Kf8tc
Posts: 3
Joined: Sat Nov 10, 2018 1:28 pm
Location: Long Beach,MS
Motorcycle: 1997 GL1500A Aspencade

Re: GL1500 rough idle hard start fix

Post by Kf8tc »

Can you put up a photo showing the correct one to plug? There are 2 by the accelerator pump, and two 90 degrees away from the accelerator pump.
Thanks
Walt

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

I guess a person should know better and just watch others struggle with there versions of the right way. Meanwhile all the wings I fixed are still fixed and running fine. Go figure. 8-)

What gets me is criticism over a fix that really does work and is time tested. Yet I see tons of postings how wonderful putting sand in the tires is (that doesn't work) and slapping marble filled frisbees there too (another snake oil device) along with fork braces and a host of other useless and expensive add-ons that don't do a thing.
toothpicks are still free. ;)

Kf8tc
Posts: 3
Joined: Sat Nov 10, 2018 1:28 pm
Location: Long Beach,MS
Motorcycle: 1997 GL1500A Aspencade

Re: GL1500 rough idle hard start fix

Post by Kf8tc »

I have spent hours looking for vacuum leaks. I do NOT think I have a vacuum leak. I have shot starting fluid everywhere, yes, even under the carbs. I have synced the carbs, ran gallons of sea-foam through the bike at idle, to no avail. I was wanting to try your fix. I just wanted to block the correct holes. When it is cold outside it doesn't seem to surge hardly at all. When it is hot out, it surges like crazy. It even backfires when you turn it off sometimes. So I know it is idling lean. All other rpms are fine. I wanted to fix it before something bad happens.

User avatar
bluthundr31
Posts: 560
Joined: Tue Jul 11, 2017 11:43 pm
Location: Morgan Hill, CA.
Motorcycle: 1991 GL1500 Interstate (Cinnamon Beige)

Re: GL1500 rough idle hard start fix

Post by bluthundr31 »

Seems fairly straight-forward, , , Once you have the air filter/housing off, , , start the engine and block the "hole" with your fingers, (he described them as dark little tubes black),then watch your idle smooth out. If it doesn't smooth out, , move your fingers to the other two holes and plug them, , , if your idle smooths out, those are the ones to plug. Easy-peasy :)

VTBikeman
Posts: 43
Joined: Mon Nov 16, 2009 12:25 am
Location: Brattleboro,VT
Motorcycle: 1989 GL1500 Double Darksider Heh Heh Heh . . .

Re: GL1500 rough idle hard start fix

Post by VTBikeman »

To GLRT: Here's a photo someone posted in another thread. Is this the toothpick size hole that needs to be plugged?


I think it's a later wing than mine.

FYI:
I just rebuilt my 89 carbs only because they leaked gas. Here are 2 mistakes to avoid:

1. Switching the throttle cables. Big surprise when I went for a test drive! Apparently I'm dangerously dyslexic.

2. Switching vacuum hoses to the wrong valves. It's confusing. It was the 2 hoses that go to the box up in the pocket cavity.

That said, after I fixed those things I now have low rpm hesitation where I did not before the rebuild. I set the idle screws as I found them. Mine have a tab on them that limit rotation to less than 1 whole turn. I would have to pull the carbs and clip off the nib to make the adjustment richer. So it seems the toothpick fix may be in order. I am to the point of getting the tupper ware off to reach the carbs in about 10 minutes, leaving the radio out.

Also, the engine sounds like it is dieseling below 2000 rpm and I'm downshifting where I didn't before. So I'm thinking cleaning the carb somehow leaned out the mix although I thought it would have richened the mix.

Another tip: if rebuilding, put longer hoses on the gas drains, gas overflows, heater hoses to the carbs and the manifold hose that goes to the rear of the air cleaner bottom. I extended air cleaner rear hose with some (1/2"?) radiator hose and plastic 1/2" pipe (pex) and hose clamps. Much easier getting the air cleaner box off and on. Heater hose: I used some heater hose and metal barbed splice tube that I trimmed to 1 barb on each end. Gives you some room to deal with jiggling the carb into the insulators on the manifold.

It took a lot of pressure to push the carb back into the insulators. Be careful not to lean on the accel. pump nozzles.

I'm happy to try toothpicks if that fixes the problem. There is not much that I hold sacred on a 30 year old bike with hidden idle jet adjusts.

Thanks for any reply.

VTBikeman

GLRT
Posts: 85
Joined: Thu Sep 20, 2012 8:35 pm
Location: New prague, Mn
Motorcycle: Many diverse types and brands - mostly reverse trikes right now
Contact:

Re: GL1500 rough idle hard start fix

Post by GLRT »

Yes the arrow is pointing to the port that should be plugged. Use a wooden round toothpick to do the job. If you do this while it is running you will immediately notice a smoother idle.



Post Reply