86 GL 1200 Aspencade stutter on light accel


Information and questions on GL1200 Goldwings (1984-1987)
  • Sponsored Links
User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Wed Jun 10, 2015 8:09 pm



Just purchased a 86 GL 1200 Aspencade.Had exhaust leaks which have been fixed.I have cleaned and rebuilt the carbs,bench synced,vaccuum synched,new fuel filter,new fuel pump.It has a stutter on light accel under load from 1200 to 2000 rpm's.After that its fine.Also on decell,has a popping from exhaust,not alot but its noticeable.Any ideas?Thanks



User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Wed Jun 10, 2015 9:06 pm

First thing...when it starts to flutter,add a bit of "choke" to enriched the fuel mixture...see if it clears up .Some 1200's needed a bit more fuel in that range..same test with the decel popping...
I raised my main needles up to fix my 84.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Thu Jun 11, 2015 8:46 pm

Your referring to the diaphragm slide needles?Wasn't in a big hurry to pull the carbs again,lol.Are those needles adjusted by a c clip or do i need some shims?If so what size would you recommend?Thanks

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Thu Jun 11, 2015 9:34 pm

Ill look back at my old post to see what I used...Did adding a bit of choke clear it up?
Did you happen to do a idle down adjustment on each carb slow speed idle jet after the carb sync or just pre-set each one.

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Thu Jun 11, 2015 9:44 pm

OK..found it...viewtopic.php?t=9179

The needle does not have a "C" clip to set the height...My caliper shows a washer near .034" or so to lift the needle..Other than the slide and bore polishing,just the normal service was done.
Take note that I did have a collapsed spring in one fuel needle valve...This raised the fuel level a few mm...I also had 2 near plugged slow speed jets....I just noticed that the tiny hole was a bit smaller than the other ones...A fine piece of copper wire was used to remove the crusty stuff that coated the port.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Fri Jun 12, 2015 7:13 am

yes 1/4 choke made it run good,and eliminated popping on decell.I set the pilot air screws at 2 turns out per service manual specs.when i first got the bike and was cleaning carbs,pilots were at 4 turns out.i didn't polish the slides or bores,they looked ok when apart,but since i'm pulling carbs again,i'll do that also.i read on another thread to use 2000 grit sandpaper for this.thanks and i'll post back with results.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sat Jul 04, 2015 11:25 pm

Hello again.Well,I polished the slides and bores on carbs.Then also raised needles with a small shim washer,,approximately .040,,now bike is perfectly smooth up until 1/2 throttle,then seems to bog and doesn't have the higher rpm power it had before shims.Suspecting I need thinner shims,but wouldn't mind another opinion before pulling carbs again.Thanks , Jamie

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Fri Jul 10, 2015 10:27 pm

ok,so i have now changed the diaphragm needle shims to .020 size.seems better,doesnt stutter on light accell, but still seems like it doesn't want to fully accell.seems like after 3500 rpms it has trouble making power.it's not misfiring,but seems like it may be overfueling??any thoughts or suggestions??thanks,Jamie

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Sat Jul 11, 2015 8:46 am

If it is running rich,you could try one quick thing.Get a long stretch of road..Run it to the trouble spot...Hold it there...turn off the fuel.See if it starts to pick back up.If it does for a second or two you can reduce the fuel level by a couple of mm.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sat Jul 11, 2015 9:44 am

thanks virgilmobile,i'll try that.another question,,i just read in service manual to have diaphragm pistons in "up" position when tightening cover.how critical is that,and could that be causing my problem?thanks,Jamie

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accelpp

Postby virgilmobile » Sat Jul 11, 2015 9:59 am

Its possible that one slide is sticking.Look see.Stick a small mirror in the plenum box...see the slides?Idle the engine...rap the throttle to 4k or so.Watch each slide rise and fall.Are they operating the same?
Due to the cap on one carb on my 1100,one slide had a difficult time rising.Rotating the cap fixed it.That slide "felt" OK by my finger but stuck with air flow.The 1200 uses a flexible diaphragm,if its in a bind,the slide may move by finger but have problems in operation.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sat Jul 11, 2015 3:58 pm

turning fuel off at "trouble spot" didn't change anything,until the carbs went dry and started dying out.i pulled the plenum housing to try to watch slides but there is screens over air intake holes so its hard to see anything.i guess i'll pull carbs again and use a vacuum on each carb to see if one is hanging up.almost tempted to remove needle shims,re-clean all passages and start from scratch.before i installed shims on needles,after the low accel stutter,this bike would make good power up to 6500 to 7500 rpm's.thanks again, Jamie

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Sat Jul 11, 2015 4:24 pm

Great.you confirmed that the problem isn't related to too much fuel in that range.Air flow is next.You seem to be on the right track.One step at a time.
Sorry it takes so much effort.I do understand.My 88 carbs took 4 times to get it right.

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sat Jul 11, 2015 5:35 pm

just can't help feeling like my shim adjustment is responsible for power loss at high rpm's.before putting shims in,bike made plenty of power all the way to the 7000 rpm range,but it had that little stutter on take off.now the stutter is gone but won't make power in high rpm's.hoping its not a trade off / lesser of two evil's thing.anyway,i've always went by the philosiphy of,,after an adjustment,if something changes for the worse,the last thing you touched is a good place to start.oh well,rain in forecast for tomorrow,will take it apart again when it starts raining.but for now,i enjoy riding the bike so much i think i'll take it out for a nice ride

User avatar
virgilmobile
Posts: 7644
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: 86 GL 1200 Aspencade stutter on light accel

Postby virgilmobile » Sat Jul 11, 2015 9:27 pm

Before you rip the carbs apart...even pulling the caps off...get a real good look at the slide action..trust me..if even one slide is sticking,the engine will stumble right about 3k and up...it has to have that air flow..
The shim should have added just a little fuel for the mid range..2-4k...you did confirm its not rich by shutting down the fuel.
Off idle studder is usually related to the slow speed jets,idle down setting,idle ports,accelerator pump...

Your train of thought is correct...when it's worse,whatever you did is the cause...You also had the caps off besides shimming the needles.
All it would take is for one diaphragm not seated exactly in the pocket or a small hole or tear in one,or even one a bit hardned to muck this up...
keep us posted...take pictures if in you wanna...especially if you find the cause....

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sat Jul 11, 2015 9:56 pm

thanks again virginmobile.i did notice when i put the shims in that the 2 diaphragms on right side looked new and 1of them was a pain to get to seat in the groove,it kept pulling out.maybe the sealing ring on that particular slide diaphragm is out of place.guess i'll start there.at least it's on number3 cylinder and easy to get at.i know it will be worth the effort to keep plugging away until its correct.it's the most smooth comfortable bike i've ever owned. thanks and i'll post back when i inspect again.Jamie

User avatar
jamie f
Posts: 80
Joined: Fri Oct 03, 2014 7:29 pm
Location: lodi wi
Motorcycle: 1986 GL1200 Aspencade, 1982 GS 850L,,wife's bike, 1981 GS1100E,sold,,Latest addition 1994 GL 1500 Aspencade.

Re: 86 GL 1200 Aspencade stutter on light accel

Postby jamie f » Sun Jul 12, 2015 9:00 am

here's an update guys.i went directly to #3 carb that fought me with diaphragm not staying in groove.slowly pulled cap back and saw it was indeed in groove,but when i pulled the cap and looked at it,i found the air bleed groove was restricted by a chunk of vaseline,which i had used to hold diaphragm in place.i cleaned it out and took it for a spin and it runs out real nice.so after all the work;exhaust leaks,stator replacement,regulator replacement,starter rebuild,new tires,new brake pads,carb rebuild and sync and shimming needles,several hours of polishing years of neglect,i'm overall very pleased with the Wing.next project is fork seals and dust wipers and new fluid(ordered)and rear shocks which will have to wait a while since bike fund is getting low.rears hold air and don't leak but from the grime/grease buildup i cleaned off when replacing tires,there is no oil left in them.thanks everyone for your sharing of knowledge and experience.it is greatly appreciated.Jamie




Return to “GL1200 Information & Questions”




Who is online

Users browsing this forum: No registered users and 2 guests