just bought 81 gs1100ex help

[sonnygs1100]

i just bought a 1981 gs 1100ex for my wife , motor was just rebuilt bored 1mm over , new 4 into 1 exhaust . still has oem air box . the friend i bought it off just changed main jets from 110 to 107.5 . it was slugish a little when you got on it , so i pulled top off air cleaner and its running alot better but it blows smoke if you rev it while sitting still so im thinking its still to rich . should i mess with carbs or ride it a little to break in motor first ? will pods instead of air box lean it out ?

[hampshirehog]

Stock mains are 107.5 I think but check out the carb sticky in the tech forum for the full spec. Could be that your mixture screws are a mile out or your filter is gummed up. Check your valve clearances too.

And welcome to the forum......

[Zook]

Opening the air box will lean it out. The pipes should have leaned it some, too.
The problem is, he leaned the MAIN jets which only come into play at WFO.
He should have leaned the PILOT jets.

Look at the color of the sparky thing insulators. Black and sooty=rich. White=lean, tan=just right.
A little rich on a new engine won't hurt-better rich than lean, but it shouldn't be putting out black smoke.

Installing pods will lean it out. make sure the carbs are synched.

[sonnygs1100]

im sure i need to synch carbs , i guess ill run it a little rich until ive got time . it runs ok im just anal about that stuff .it only puffs smoke when i rev it quick to about 8grand while its sitting . ive not rode jap bikes in over 15 years , i forgot how much fun they were . ill probably only ride my harley when my wife wants to ride the gs .

[chef1366]

Take off the airbox lid and try these size jets
117.5 main jet
47.5 pilot jet
idle mixture screws out three turns
If you have any hesitation on throttle up you will also have to shim the needle.
Do you have a good or new air filter?
Are the valves adjusted?
Is the petcock good?

[sonnygs1100]

Take off the airbox lid and try these size jets
117.5 main jet
47.5 pilot jet
idle mixture screws out three turns
If you have any hesitation on throttle up you will also have to shim the needle.
Do you have a good or new air filter?
Are the valves adjusted?
Is the petcock good?

if its running rich why go bigger on jets ?
is thier a tutorail on thes carbs ?
their is no hesitation now with top off air box.
air cleaner is brand new ergo , i pulled it and bike stoped smoking .
i would have thought the performance shop in austin set valves when they built motor , are they hard to adjust ?
no clue on petcock , do you need a free flow on when you do performance mods ?
thanks for every ones help , im realy liking this bike .

[chef1366]

Sounds like the filter was over oiled or too air restrictive.
The jet sizes I gave you are a good start.
The valves are very easy to adjust. A manual will show you.

[Suzuki mad]

What colour smoke does it 'blow?'

If its blue then its likely that the PO didn't change the valve guide seals when they did the rebore.

The EX should have a paper cartridge type filter. There is a rubber gasket between the cartridge holder and the main airbox/carb part and this rubber perishes and can be a so and so to seal as the edges to the box can get damaged over the years.

Chef1366 jet sizes will give you a good starting place. Its worth checking the valve clearance being a cam follower version than the shim and bucket as the adjusters have a habit of getting bigger with use. Also poor performance can be down to the condition of the camshafts. Do a valve check and have a quick visual check of the cam lobe's aswell.

Suzuki mad

[sonnygs1100]

ok the cams are new
the paper element is new
it is now only smoking if you let it idle for a minute then rev the motor , if you rev it from 2000rpm it does not smoke
perfomance is good with air cleaner top off .
im thinking pilot jet is to big , can i pull pilot to see size with out pulling carbs ?
smoke smells rich gassy