Running rich I think


Information and questions on GL1500 Goldwings (1988-2000)
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alca
Posts: 9
Joined: Thu Apr 09, 2020 7:52 am
Location: Surrey,England
Motorcycle: 1991 Goldwing GL1500 Trike

Running rich I think

Post by alca »



Hi all
With apologies to admin I think I put this post in the wrong place to start with so have redone here.

I was checking if my GL1500 1991 Vintage was running rich and had the following problem.


cl1500 wrote an article in 2013 on a way to check for rich running.

I tried to check my 1991 GL1500 for running rich, but when I tried to do this I could not get the revs to stay stable, after letting the engine warm up to operating temperature I tried to adjust the idle speed to 850rpm.
I get to 750rpm but then it jumps to 1250rpm, if I try to increase a little to 850rpm it jumps to 1250rpm with just a touch on the screw, I cannot get any speed range between 750 & 1250 by the adjustment at all.
If I leave it to run on idle at 750rpm it will jump to 1250rpm and then back to 750 without touching anything, anybody any ideas where I should look to try and correct this problem or what could be doing this.
many thanks
Alan



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ct1500
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Re: Running rich I think

Post by ct1500 »

Running rich, not likely. Running lean is the more likely culprit. An engine running rich will just bog down, what you are experiencing is a lean surge. The engine will not run at its' specified idle RPM so to get more fuel an owner will increase idle RPM until the main jet starts kicking in. As the engine RPM increases in a surge it uses what little fuel is available until it runs out again repeating over and over. All caused by blocked pilot jets 90% of the time. Will the engine run better at faster speeds above idle? I would bet that the history will show a long period of inactivity and this condition did not appear overnight. Anybody have their hands working on the machine recently?
Remove air cleaner to gain access to the carb throats and apply just a dribble (drip) increasing of carb clean spray to one then the other carb. If the addition of the spray (alternate fuel source) makes the RPM increase and smooth out in one or both then the fun begins and you go on to find the cause of this lean condition. :)
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HandymanHerb
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Motorcycle: 1997 GL 1500 SE Aspencade

Re: Running rich I think

Post by HandymanHerb »

I just bought a 97 Gl 1500, mine is running rich and everyone around can smell it, it has a slight surge,was more but I think running non ethanol fuel,Sea Foam and putting many miles on it has helped some, starts right away now but still to rich at idle, I got 30 MPG pulling the trailer on an hour long trip,half on back roads at lower speeds, around town I get around 28 MPG, So it may just be a rich idle problem.

I checked the service manual and it has so many things to check I need help on narrowing it down or someone in Central Florida willing to work on them

alca
Posts: 9
Joined: Thu Apr 09, 2020 7:52 am
Location: Surrey,England
Motorcycle: 1991 Goldwing GL1500 Trike

Re: Running rich I think

Post by alca »

ct1500 wrote:
Fri Apr 24, 2020 6:30 pm
Running rich, not likely. Running lean is the more likely culprit. An engine running rich will just bog down, what you are experiencing is a lean surge. The engine will not run at its' specified idle RPM so to get more fuel an owner will increase idle RPM until the main jet starts kicking in. As the engine RPM increases in a surge it uses what little fuel is available until it runs out again repeating over and over. All caused by blocked pilot jets 90% of the time. Will the engine run better at faster speeds above idle? I would bet that the history will show a long period of inactivity and this condition did not appear overnight. Anybody have their hands working on the machine recently?
Remove air cleaner to gain access to the carb throats and apply just a dribble (drip) increasing of carb clean spray to one then the other carb. If the addition of the spray (alternate fuel source) makes the RPM increase and smooth out in one or both then the fun begins and you go on to find the cause of this lean condition. :)
Hi ct1500

Many thanks for your reply and the information you gave, in answer to your questions, Yes it does run ok at faster speeds than idle and is very smooth and quite.
And right again you would win the bet, it was off the road by previous owner for 3 years being converted to a trike.
I rode it from Cornwall to Surrey (approx 300 mile) and it did not miss a beat, I have had my hands on it but left the carbs alone as I did not have any experience of these, since then I have changed engine oil,oil filter,petrol filter,air filter also the cam belts.
I will take on board your advice and do the test you suggest and then look for the cause, one question can you clean the pilot jets without removing them (air line blast) or do you think they will be gummed up to much.
Once again many thanks for your help, I will post back with the results,
Alan

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ct1500
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Re: Running rich I think

Post by ct1500 »

alca wrote:
Sat Apr 25, 2020 1:47 pm
I will take on board your advice and do the test you suggest and then look for the cause, one question can you clean the pilot jets without removing them (air line blast) or do you think they will be gummed up to much.
Once again many thanks for your help, I will post back with the results,
Alan
Air will not work on the cement like crud that is now in there. The object for you is to get this done right the first time which is why I suggest new Honda pilot jets, kits and possibly float valves. While in there you will want to replace carb insulators and a vacuum hose under the carbs while removed. Cutting corners due to cost is not advised and with some new parts will go on for another 30yrs. With engine off move the slides with your finger and check that there is no roughness or sticking in their movement. If sticky or hanging up spray a little brake parts cleaner on them while moving back and forth followed by a little silicone spray. With engine running and carb slides visible verify proper operation of slides by cracking throttle open hard and fast to check movement (opening) which should be identical between the two carbs. No need to go above 3500-4000RPM or so. :)
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ct1500
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Re: Running rich I think

Post by ct1500 »

HandymanHerb wrote:
Sat Apr 25, 2020 1:08 pm
I just bought a 97 Gl 1500, mine is running rich and everyone around can smell it, it has a slight surge,was more but I think running non ethanol fuel,Sea Foam and putting many miles on it has helped some, starts right away now but still to rich at idle, I got 30 MPG pulling the trailer on an hour long trip,half on back roads at lower speeds, around town I get around 28 MPG, So it may just be a rich idle problem.
I checked the service manual and it has so many things to check I need help on narrowing it down or someone in Central Florida willing to work on them
I will be north or south of Tampa in about 3yrs. for retirement, can it wait? :D
Local and need repair help with your 1500, Valkyrie or ST please click contact
Nothing leaves my shop till its' perfect
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HandymanHerb
Posts: 31
Joined: Sun Mar 15, 2020 3:12 pm
Location: Orlando,Fl
Motorcycle: 1997 GL 1500 SE Aspencade

Re: Running rich I think

Post by HandymanHerb »

Might be a little long to wait as I can feel it at speed, just wish it wasn't so many things to check for running rich, I can get all the plastics off to save time, but need someone who knows what to check and why, guess I need to keep asking

alca
Posts: 9
Joined: Thu Apr 09, 2020 7:52 am
Location: Surrey,England
Motorcycle: 1991 Goldwing GL1500 Trike

Re: Running rich I think

Post by alca »

ct1500 wrote:
Sat Apr 25, 2020 4:52 pm
alca wrote:
Sat Apr 25, 2020 1:47 pm
I will take on board your advice and do the test you suggest and then look for the cause, one question can you clean the pilot jets without removing them (air line blast) or do you think they will be gummed up to much.
Once again many thanks for your help, I will post back with the results,
Alan
Air will not work on the cement like crud that is now in there. The object for you is to get this done right the first time which is why I suggest new Honda pilot jets, kits and possibly float valves. While in there you will want to replace carb insulators and a vacuum hose under the carbs while removed. Cutting corners due to cost is not advised and with some new parts will go on for another 30yrs. With engine off move the slides with your finger and check that there is no roughness or sticking in their movement. If sticky or hanging up spray a little brake parts cleaner on them while moving back and forth followed by a little silicone spray. With engine running and carb slides visible verify proper operation of slides by cracking throttle open hard and fast to check movement (opening) which should be identical between the two carbs. No need to go above 3500-4000RPM or so. :)
Hi ct1500

Have tried as suggested above and the carbs look really good from what I can see they are immaculately clean in fact they look almost new, the butterfly shows no sign of wear or staining of any sort, the slides move easily by hand, however they do not move a lot with the engine running when I blip the throttle (they move about 1/4 - 1/2 inch or so when revs up to about 3500rpm they both move the same amount) is this as much as they should move at that kind of RPM?
If they should move more than this can you tell me please where should I be looking for the problem. I take it it's vacuum that moves them (but I could be wrong :roll: )
Before I strip them down and buy new jets etc I would like to do a bit more investigation into finding the problems.
Many thanks for your help.
Alan

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ct1500
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Re: Running rich I think

Post by ct1500 »

That will be about all they move at that RPM and in neutral. The slides are secondary mains and are closed with no effect on idle speed/mixture. If you would like to see more slide action you can put bike running in 3rd or 4th gear on center stand, apply rear brake for a few seconds and open throttle effectively putting a load on the engine. Or just a quick ride up the street making sure nothing can be drawn into carbs and engine except clean air. :!:
Local and need repair help with your 1500, Valkyrie or ST please click contact
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alca
Posts: 9
Joined: Thu Apr 09, 2020 7:52 am
Location: Surrey,England
Motorcycle: 1991 Goldwing GL1500 Trike

Re: Running rich I think

Post by alca »

ct1500 wrote:
Tue Apr 28, 2020 3:36 pm
That will be about all they move at that RPM and in neutral. The slides are secondary mains and are closed with no effect on idle speed/mixture. If you would like to see more slide action you can put bike running in 3rd or 4th gear on center stand, apply rear brake for a few seconds and open throttle effectively putting a load on the engine. Or just a quick ride up the street making sure nothing can be drawn into carbs and engine except clean air. :!:
Hi
Thanks once again for your reply, all checks out as your above info so the only thing I need to sort is the idle speed issue, the carbs are now off and on the bench ready to be stripped down and refurbished (this could take some time as I still need to order the parts), now need to check all the vacuum pipes and bits underneath the carbs, it does need a good clean under there and hope I can get it all back together again, taking it apart is one thing getting it all back together is another :lol:.

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HandymanHerb
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Location: Orlando,Fl
Motorcycle: 1997 GL 1500 SE Aspencade

Re: Running rich I think

Post by HandymanHerb »

I think miles,ethanol free gas and Seafoam fixed my carb problems, last night I came home from a ride and my idle was at 1200 steady, so I turned it down to 800, it held steady, no jumping in RPM's

At idle all I smell now is Seafoam, not smelling gas fumes, So took it for a good ride this morning even with the Love Bugs out and it ran great, wasn't getting any surging at all not even on cruise control.

So I think it was sitting too much for the last few years the second owner had it with ethanol fuel in it, Never good for anything to sit with ethanol fuel in it



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