Goldwing 1500 1988


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YvonGB
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Motorcycle: 1988, Goldwing 1500

Goldwing 1500 1988

Post by YvonGB » Fri Jul 13, 2018 11:53 am



Hi everybody,

This is my first time on a technical chat. I'm french speaking, so I hope you will excuse my wording.
I bought this 1988 GL 1500 3 years ago. Although it drives fine, I noticed from the start that all the spark plugs had excessive carbon on them. So I did a carb job last winter. I did all the suggested adjustments and went on the road. I had increased power and everything was fine. Then, a few weeks ago, after I started, it sound as if it was running on 3 or 4 four cylinders. Looking at the plugs, I noticed again that there was a lot of carbon on them. So I thought there was too much fuel in the carb. So I did three successive adjustments on the pilot screws. Finally, I had less than a turn un each carb. The problem still persist. I checked the carb control unit following maintenance manual, the pulse generators, sprayed some soapy water on visible hoses and I just changed the CDI. As I did, I again adjusted the pilot screws as indicated in the maintenance manual for a 1988 model: 3 full turns (it was 3.5 when I dismantled it last winter). I started it, rolled the throtle a few times and everything looked fine. But ounce on the road, it started to hesitate and RPM would go down at idle. On highway, works great. Lots of power and acceleration. But ounce I bring it back to idle, it gives the same impression of 3 of 4 cylinders firing, and there's this big fuel and exhaust smell with some backfires. If I open the throttle again, it hesitates and then accelerates just fine. Any one has any idea what might be the problem ? Next step, I'll have to go the the dealer. Thanks !



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bluthundr31
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Re: Goldwing 1500 1988

Post by bluthundr31 » Fri Jul 13, 2018 7:15 pm

WELCOME ABOARD YvonnGB!!!

I haven't experienced your exact issue, , , but my first thought is the spark plugs. If they are the correct plug, and gaped properly you might want to consider "stepping up" to the next higher "HOTTER" plug for a few hundred miles and check them to see how they perform.

Next, I would consider the Plug wires, , , If they're 30 yrs old, they could be cracked and you could have some "arcing" that will cause havoc with the plugs firing off properly.

DaveO430
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Re: Goldwing 1500 1988

Post by DaveO430 » Fri Jul 13, 2018 7:18 pm

Did you synchronize the carbs? With the engine running and the air filter out look down in the carbs and see if there is fuel bubbling out of the main jets. The mixture adjustments will do very little toward fixing a bad over rich or lean condition.

YvonGB
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Motorcycle: 1988, Goldwing 1500

Re: Goldwing 1500 1988

Post by YvonGB » Sat Jul 14, 2018 9:10 am

Good morning,

Thanks for taking time to answer. I really appreciate. Now I wonder. I did synchronize the carbs and it always did run fine with the same type of spark plugs. The other day we had above 90 degrees fahrenheit temperature and the engine was very smooth all day. But then, as I was idling in front of the house, RPM dropped abruptly for just no reason. Could it be one of the coils, or a sensor ?

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bluthundr31
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Re: Goldwing 1500 1988

Post by bluthundr31 » Sat Jul 14, 2018 2:27 pm

Once you are confident with the carbs are sync'd, the plugs are in good shape, and the plug wires are in good condition, , , , the pulse generators/ECU could be the next step. Its possible that one of them going bad could cause your symptoms, but not quite as common as the carbs/plugs.

Your comment about smelling strong gas smell from engine/exhaust could be a different issue, but bothers me because THAT could be where you loss of "idle" is going. The fuel petcock should be checked closely.

Keep us up-to-date on how you proceed from here. Good luck

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Erdeniz Umman
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Re: Goldwing 1500 1988

Post by Erdeniz Umman » Sat Jul 14, 2018 4:46 pm

Also the ambient air temperature sensor and/or the coolant temperature sensor may be the culprit. If they are faulty the ignition timing will be wrong.

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Sat Jul 14, 2018 6:09 pm

HI,
I followed your suggestion and I changed the spark plugs for hotter ones. When I pulled the old ones, the ones on the left were nice and clean. The ones on the right were filled with carbon. I checked the pulse generators at the CDI station. The resistance is within limits. I also checked the Tw sensor from the CDI station, and the resistance is OK. After all that, started the engine and let it run for ten minutes. Smooth and the engine responds well to the throttle. So, I took it for a small ride around the block. As I try try to accelerate, it hesitates and then as it gains RPM, it goes like a rocket. But after a few minutes of this stop and go, RPM goes down and it sounds again as if it is running on just a few cylinders. And this is the point where the fuel smell comes in. Thanks for your concern !
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ct1500
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Re: Goldwing 1500 1988

Post by ct1500 » Sat Jul 14, 2018 8:16 pm

Every other 1500 on the road runs just fine with the stock spark plug and had nothing to do with your problem so go back to a standard plug. You likely have an issue with the right carb running rich.
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YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Sat Jul 14, 2018 8:55 pm

Hi,

Both carbs pilot's screw were fit at 3 full turns out. When I saw that the right hand side was full of carbon, I turn the pilot screw in haft a turn, which I believe is a lot. Same result. A few days ago I ordered a set of pulse generator on Ebay. Maybe... Thanks again !

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Erdeniz Umman
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Re: Goldwing 1500 1988

Post by Erdeniz Umman » Sun Jul 15, 2018 3:28 am

If the problem is only on one side of the engine it should not be a ignition problem since the ignition on the left and right cylinders is produced by the same ignition coil and the same PGs, so it should be a fuel related issue.

Or maybe the ignition cables are not in the correct plugs, I remember an issue about this.

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Sun Jul 15, 2018 8:46 am

Hi,
Let's suppose that I mixed two cables (did I do that ?). You can't mixed the 3 of them because of their length. So one of the 3 plugs should be clean. Which is not the case. And for the temperature sensors if that would be the problem it would affect both sides. Now I noticed that ounce I get the bike running smoothly at idle, if I put my hand behind each exhaust, I can feel their is less pressure coming from the right hand side. So let say I have an ignition problem on the right hand side. If I already changed the plugs and the CDI, what would be next ? The pulse generators ? The carburetor control unit ? I checked them already following Clymer's instructions and they seem to work OK. Thanks again to all of you for your thoughts.

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Erdeniz Umman
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Re: Goldwing 1500 1988

Post by Erdeniz Umman » Sun Jul 15, 2018 11:49 am

The exhaust pressure may not be a correct way to diagnose the problem, because there is a collector box where all exhaust manifolds are connected.

Pulse generators both work for all cylinders, so they can't be an issue.

It seems like a carburetor issue to me.

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bluthundr31
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Re: Goldwing 1500 1988

Post by bluthundr31 » Sun Jul 15, 2018 12:54 pm

Seems like the strong smell of gas and the poor idle, running on 3 cylinders, are happening at the same time after the engine warms up.

Could that right side carb have an "issue" with the boot, or a seal that is leaking after the engine temp rises? The Tw sensor sounds OK, but did the Ta sensor check out normal?

I originally thought the gas smell was unrelated, but its sounding more like you should find where that gas is coming from, , that right carb would be the first "suspect".

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Sun Jul 15, 2018 1:17 pm

And how about the carb control unit ? I just overhauled the carbs last winter and I know what kind of a job it is to look into this. I’m scared ! :o

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bluthundr31
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Re: Goldwing 1500 1988

Post by bluthundr31 » Mon Jul 16, 2018 1:09 am

If you just remove the center shelter, and the air cleaner, I think you should be able to see the area well enough to tell where the gas smell is coming from. Yes, it can be tight quarters in that area, , , but last winter you already did MORE than just "looking" for the gas leak. Your comment " I noticed from the start that all the spark plugs had excessive carbon on them." makes me think the problem has existed for quite a while, but is getting progressively worse. You need to fix it before it gets dangerous.

My '91 GL1500 does not have a carb control unit, so I'm not familiar with them, , ,hopefully someone has more info for you.

GillesGLW
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Re: Goldwing 1500 1988

Post by GillesGLW » Mon Jul 16, 2018 6:59 am

Hello YvonBG,

Switzerland here, french speaker as well!

I'm currently riding a 1500 from 1989 and your issue reminds me of a few issues I had when I bought my bike.

I firstly changed the trigger wheel (https://cyclemax.com/inc/sdetail/gl1500 ... 424/159787), because my bike was, as well, hesitating when going out from idle.
Then I used a colortune (https://www.classicautoelec.com/fr/colo ... -14mm.html) plug, to check and fine tune my carbs.

Both things helped me a lot to get my bike running well. Let me know if you need further assistance.

Cheers,
Gilles

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virgilmobile
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Re: Goldwing 1500 1988

Post by virgilmobile » Mon Jul 16, 2018 7:49 am

My 88 flooded on the right bank.The bowl vent was plugged.Remove the crossover tube and verify both carbs are venting.

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Thu Jul 19, 2018 9:03 pm

Hi everybody,
I have been quite busy recently, so I did not have time to look at my bike. But today I did. Left hand side plugs are clean since I changed the CDI. But the right hand side are just filled with carbon. I looked down underneat the carbs and found a punctured rubber hose that fits in the right hand side manifold. I fixed it and refit the whole thing. When I started it, (still running square) I noticed that gas was just running down from a side hole on the right hand side carb. Could it be that vent hole thing. Where is it located and how do I check that ? Thanks for your support. I took this whole thing apart six times already. I am just about to give up.

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Fri Aug 03, 2018 10:09 am

Hi everybody,
I have been very busy lately, trying to find a solution to my engine problem using your cues. Here's the latest update. After multiple adjustments, electrical verification, replacing CDI and punctured hoses, taking apart and adjusting floats on my carbs (even watched videos on how to) I found out that the float needle that I replaced last winter were wrong. They were part of a complete kit for '88 model. Although the stem are identical, the small button on top and the little hook are different. So I replaced them with the appropriate ones and all my problems just disappeared like magic. I put 300 miles in one day and it runs like never before. But that was 3 days ago. Yesterday it started something else. Starts well but with low idle, no gas smell, plugs are clean but it runs as if there is water on high tension wires. I was counting to leave on vacation next monday. Plans may have to change.

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bluthundr31
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Re: Goldwing 1500 1988

Post by bluthundr31 » Fri Aug 03, 2018 2:03 pm

Use the "Idle adjustment knob" inside the gas tank cover to turn up the idle to 800-900 rpm. That knurled knob was set to idle with those "wrong" jets, , ,a simple adjustment should bring you back to what you want for a smooth idle. Good catch on those jets!!!!

YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Fri Aug 03, 2018 5:15 pm

Hi, thanks for your reply,

I decided to take a ride, just to see how it behaved today. It started fine with steady idle. I drove around and still going OK. Decided to go out of town. Lots of power, no hesitation, went out on a country road, still ok, stopped for a moment: idle steady around 900 RPM. Everything seemed fine. Kept on riding for a while and everything was fine. Came back in town, and as i was sitting at a corner street, idle slowly started to go down. This is the point where the performance started to deteriorate. The engine hesitates, there is constant trembling and even some backfires, idle fluctuates and at one point the engine just died and was hard to start. So the problem is intermittent.
Yesterday after I had experienced the problem, I could remove the cable from any spark plug on the left hand side with no impact. The same action on the right hand side and the engine would stop. That is why I believe this is an electrical problem. I checked the CDI, the carburetor control unit and the pulse generators and everything is fine. This problem remembers me that after I wash the bike and then start it, inevitably it behaves just like that. So I stop the engine fort maybe 10 minutes, start it again and it drives fine, just as if humidity evaporates. Thanks again for your comments. They are more than welcome.
Yvon

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Erdeniz Umman
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Re: Goldwing 1500 1988

Post by Erdeniz Umman » Mon Aug 06, 2018 8:43 pm

There maybe cracks on the spark plug wires which causes unwanted jumps to the chassis of the bike. You could visually check it as in the video below.



YvonGB
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Re: Goldwing 1500 1988

Post by YvonGB » Fri Aug 31, 2018 9:01 am

Hi everybody,

This is the final chapter of my engine problem. Remember that I found out that float needles in the carbs were not the right one ? Well, that was not the only parts that were wrong. After multiple verifications on different components on the engine, I decided to open up the carbs one more time. So I looked at the jets. They looked identical to the ones I removed. But, looking at the size number printed on them... they were different. The ones I removed were size 50, the ones I installed were 65 ! Looking very closely I could see that effectively they were different. No matter the adjustments I made, the carbs were always flooded with gas. In conclusion, it's not because it says '88 on the box that you should be confident that these are the right parts.
To all of you who took some time to give me your advices and support, THANK YOU and enjoy the end of the summer season

Yvon



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