1200 top speed and rpm


Information and questions on GL1200 Goldwings (1984-1987)
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uscchemguy
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Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

1200 top speed and rpm

Postby uscchemguy » Sun Aug 31, 2014 12:05 pm



Hello all! I have a bit of a problem on my newly acquired goldwing. I have been working on this bike patiently since April. The bike idles great and has good response up til about 2000 to 2500 rpm's, and then it seems to bog down. If take the bike out I can only get it up to 55 or 60 and that's after I bring the choke up, otherwise it's more like 50 to 55. Also when I am driving, as I increase gears it seems my max rpms drops lower and lower. I can hit 6000 in first, 5500 in second and so on. I can not get the rpms above 3500 in 5th or hit 4000 in 4th. I have run a couple cans of seafoam but no change. I bought an 85 honda prelude fuel pump to make sure the pump is not the problem. The fuel spews out of the petcock when I remove the fuel lines. Any ideas beside removing the carbs for overhaul? When I bought the bike it was not running and the po said it was mostly likely the fuel pump. But it turned out to be the pulse coils. When I purchased the used pulse coils I also purchased a used cdm box just incase that was also bad. Bike runs the same with either cdm. The bike has zero problems charging, also did the fan controller swap so the temp is well regulated. I replaced the front head bearing, so no more wobble. New oil, new final drive oil, new air filter, New fuel filter, new spark plugs. All plug wires pass resistance, primary and secondary coil windings also pass resistance. I have not checked how well carbs are synced so I will probably be building something. After all of this I am starting to get the itch but obviously I cant ride it much like this. Thanks for the help, out of central Florida!



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WINGER3
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Motorcycle: current 2005 GL1800ABS previous GL1200A GL1500K GL1100A CB350 GL650I VFR1000 ST1100 GL1200A GL1500I + many other brands

Re: 1200 top speed and rpm

Postby WINGER3 » Sun Aug 31, 2014 1:43 pm

First off, welcome to the best site there is on Goldwings. I will put in my 2 cents on your problem, I would look at the high speed jets not giveing enought fuel under lode witch means pulling the carbs, I would also run a compression test to make sure the valves are not leaking or rings worn out. It sounds like you have done everthing right. It's early so I expect you will get many others with there thoughts on your problem, so help is on the way. Good luck. :mrgreen:
DON'T DESTROY IT-RESTORE IT

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Sun Aug 31, 2014 1:48 pm

Thank you winger, that was my guess also but I would prefer to rule everything out that I can before pulling the carbs.

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WINGER3
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Location: Orange, California
Motorcycle: current 2005 GL1800ABS previous GL1200A GL1500K GL1100A CB350 GL650I VFR1000 ST1100 GL1200A GL1500I + many other brands

Re: 1200 top speed and rpm

Postby WINGER3 » Sun Aug 31, 2014 3:35 pm

Just for when you do pull the carb's, they are much easer then the 1100 and 1500, you don't even have to remove the #1 & 3 caps from the carbs to get them out, just tape the tops of each to prevent scratchs and they will come out, #1 being the tightist to clear the frame. Remember to mark each carb to head tube so you get them back on right. I have pulled and rebuilt all 3 models and the 1200 is the easyist. Bob :mrgreen:
DON'T DESTROY IT-RESTORE IT

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Mon Sep 01, 2014 10:29 am

thanks for the heads up. I will check the compression tomorrow just to rule that out. I do get the typical 10 seconds of light smoke when the bike is sitting on it side stand for a few days. :roll:

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HawkeyeGL1200
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Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: 1200 top speed and rpm

Postby HawkeyeGL1200 » Mon Sep 01, 2014 11:08 am

Have you tested the new fuel pump to make sure it is working?

The reason I ask is, if it isn't insulated from the frame with the rubber mounts, I don't believe it will work. I'd verify good fuel flow before I pulled the carbs.
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

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uscchemguy
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Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Mon Sep 01, 2014 11:28 am

The pump came with rubber mount that I did use. I can feel the pump ticking as it idles and as I rev it up. I guess I should verify by measuring the flow. Thanks

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HawkeyeGL1200
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Location: Courtland, Va.
Motorcycle: 1984 GL1200 Interstate
1981 GL1100 Interstate

Re: 1200 top speed and rpm

Postby HawkeyeGL1200 » Mon Sep 01, 2014 11:35 am

Just because I wrote it, doesn't mean anything. It just seems like the bike is starving under load. It certainly could mean you need to rebuild the carbs, but not getting fuel to the carbs will act in a similar way.

uscchemguy wrote:The pump came with rubber mount that I did use. I can feel the pump ticking as it idles and as I rev it up. I guess I should verify by measuring the flow. Thanks
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Mon Sep 01, 2014 12:06 pm

Thanks Hawkeye, yea that was actually what I was hoping it would be when I went out and purchased the pump. Your ideas are greatly appreciated. It is small things like that in which I do not want to miss. Thank you again. :)

Armis
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Joined: Fri Jun 20, 2014 11:58 am
Location: Livermore, California
Motorcycle: 1984 GL1200I

Re: 1200 top speed and rpm

Postby Armis » Mon Sep 01, 2014 12:20 pm

I have a 1200I that sat in my garage, unused for close to 5 years. One day I decided to get it running, took the carbs off to see what they looked like and gave them a light cleaning. They looked surprisingly good, considering that I hadn't taken any long term measures for storing the bike. A new battery was in order; as were front fork seals and front brakes, the seals and brakes needed fixing even before I quit riding the bike, years ago. I also replaced the timing belts, they appeared to have been the originals and had around 36,000 miles on them. The tires look great, with plenty of tread, but I know they need to be replaced before I start riding any long distances.

Then I started the bike, synchronized the carbs and took her out for a short test hop. All was well until I started the return loop to my house, that necessitated going up a fairly steep grade that climbs to 1500 feet. I was riding into a strong headwind and as I went up the grade, I noticed the bike wouldn't go any faster then 60 mph in 5th gear. Other than that, it seemed to have good acceleration and didn't miss a beat. I got home; pulled the spark plugs out, checked the color and the gap, and decided nothing was wrong with them. I could see through my fuel filter and it didn't appear abnormal, but I decided to pull it off anyway. I blew through it and the air seemed to pass through unimpeded; but because it was off, I replaced it anyway.

Replacing the filter made all the difference in the bike, I went back and duplicated the ride over the hill, this time easily hitting 80 mph in 5th gear, on the grade. I purposely slowed down in a couple of spots and immediately regained my speed with no downshifting. That was the first time that I've ever had a bad filter. Try changing yours if you haven't done so already.

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Mon Sep 01, 2014 12:27 pm

Thank you for your response. I replaced the filter twice, once when I first got the bike and again last week, but I was getting the one from napa. I have read post where that filter has worked great for others. I have it fixed about an inch off the engine so it doesn't get to hot. Thank you!

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Fri Dec 05, 2014 9:13 pm

Ok, so I pulled the carbs. I had no idea what to expect since I haven't had the bike longer than a year. What I found was a completely clogged mainjet in one carb and two other carbs had slide diaphragm each with a hole in them. I cleaned the carbs and repaired the diaphragm using some honda bond. I put the carbs back together and now she will do 70 @ 3700 rpms with ease. Honda bond has lasted a couple weeks now and I have been riding it almost everyday. I drive it to work which is 49 miles and 30 of that is at 70 mph.

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uscchemguy
Posts: 8
Joined: Wed Apr 02, 2014 6:47 am
Location: webster, Florida
Motorcycle: 1985 1200 interstate

Re: 1200 top speed and rpm

Postby uscchemguy » Fri Dec 05, 2014 9:19 pm


This was a pretty dirty intake

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WINGER3
Posts: 202
Joined: Fri Oct 05, 2012 11:41 pm
Location: Orange, California
Motorcycle: current 2005 GL1800ABS previous GL1200A GL1500K GL1100A CB350 GL650I VFR1000 ST1100 GL1200A GL1500I + many other brands

Re: 1200 top speed and rpm

Postby WINGER3 » Sat Dec 06, 2014 12:25 am

I'm glade you got the problem fixed, I had the same problem with mine, #4 main jet was solid, I had to use a drill bit to get it cleaned out (use a bitt 2 sizes smaller then the jet) and now it will hit 80+ as fast as a speeding ticket (bullet). Enjoy the ride. :mrgreen:
DON'T DESTROY IT-RESTORE IT

84Gl1200rider
Posts: 5
Joined: Fri Jun 12, 2015 10:20 am
Location: Easley SC US
Motorcycle: 1984 gl1200I interstate

Re: 1200 top speed and rpm

Postby 84Gl1200rider » Wed Jul 01, 2015 12:53 am

Hello hey what is a fan controller swap I have a 84 interstate with heating problems thanks




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