Bogging under acceleration and engine noise while cruising

[TK83GS1100]

I have a 83 GS1100L

it was a barn find and it need the usual to get it going again. Here is what its doing now under acceleration it is bogging down just a little then it will slowly recover and pick up speed. It will do this in all gears. The problem seems to begin about 3000rpm then end after 4000rpm.

What I have done is cleaned and flushed the fuel tank, cleaned and inspected the fuel petcock (vacuum type) but I am not sure if the petcock is working correctly, replaced the fuel and vacuum lines, cleaned and blew out all 4 carbs checked all float levels, installed new spark plugs, checked and tested the ignition (electronic) the stator and they are working fine. Replaced the Cyl to carb intake stacks and now I am scratching my head still the same problem, what could be going on?

At start up and idle all four cyl are running good and smooth no miss'es nice note from the exhaust and when checking the plugs all 4 look the same light brown ash on the electordes.

It shows all the symptoms of running low on fuel like the bowls are emptying out prematurely. My thoughts are the fuel tank and the petcock need attention to establish full fuel flow to the carbs.

Second problem is a noise from the upper part of the engine at cruising speeds sounds like a light knock could this be a valve clearance problem?

Here is a video of a cold start and warm up on this bike. http://www.youtube.com/watch?v=AiQAXaGspFY

I really need some input on this one. Thanks in advance and ask any questions.

[almarconi]

First off welcome to the forum. Nice bike you have there. Two things you didn't mention, that should be done is valve adjustment and vacuum sync the carbs. When you cleaned the carbs did you take them completely apart and soak them, replace the o-rings and reassemble them? Did you do a bench sync on the carbs. How are you adjusting the mixture screws? Highest idle method or colortune?

[BassCliff]

Greetings and Salutations!!

Hi Mr. TK83GS1100,

Hey, you've got yourself a nice example of a fully dressed GS1100GL. Here's your very own "mega-welcome". Pay close attention to the "Top 10 Common Issues", especially the Carb Rebuild Series. Yes, check those valve clearances! Let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. You'll find lots of GS lovin' there too.

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Jon Burke]

Don't forget about the o-rings between the carb boots and cylinder head that are known to harden up and leak air.

First off welcome to the forum. Nice bike you have there. Two things you didn't mention, that should be done is valve adjustment and vacuum sync the carbs. When you cleaned the carbs did you take them completely apart and soak them, replace the o-rings and reassemble them? Did you do a bench sync on the carbs. How are you adjusting the mixture screws? Highest idle method or colortune?

[TK83GS1100]

Don't forget about the o-rings between the carb boots and cylinder head that are known to harden up and leak air.

Yes sir I replaced the O rings when I installed 4 NEW Cyl to carb intake stacks.

[TK83GS1100]

[QUOTE=BassCliff;998989]Hi Mr. TK83GS1100,

Wow thanks for all the INFO I have been reading and downloading some great stuff. Thanks for the Great Welcome and Info.

[TK83GS1100]

First off welcome to the forum. Nice bike you have there. Two things you didn't mention, that should be done is valve adjustment and vacuum sync the carbs. When you cleaned the carbs did you take them completely apart and soak them, replace the o-rings and reassemble them? Did you do a bench sync on the carbs. How are you adjusting the mixture screws? Highest idle method or colortune?

No valve adjustment yet but its now on my list. After looking at some of the links at Cliffs website I now know I didn't completely disassemble the carbs and no I didnt replace a single O ring. I did however follow the links from my welcome comment and promptly ordered them. Thanks for a great start on my repairs.