Gs1100g super rich

[chuck hahn]

Customers bike, Has stock jetting according to the parts fiches. Float heights are correct. Bike runs great on new plugs but quickly carbon fouls them and causes loss of cylinders. I have an add asking for good replacement needle jets.
So if i cant find needle jets my next thought was go down on the main jets in an effort to counter the holes in the needle jets being worn and allowing too much fuel through.
What are your thoughts on reducing main jet size??

[Nessism]

How many miles are on the bike? Unless it's north of 75,000 miles, it's hard to imagine that much wear on the needle jets.

[Rijko]

I bought a box of fake NGK plugs once.
They would become real sooty real quick .... and drop the cylinders.

So i put in 4 new ones, took me some time to figure out all 4 new plugs went bad ...
Are you sure they are proper plugs Chuck ?

[rphillips]

I'm no carb guru, but wear from fuel flowing through or across a brass part, enough to cause the problem you explain, just don't seem right... If running rich during normal riding, would it be reasonable to lower the needle a little, maybe more if as bad as you say.

[unfocused]

To set up a CV carb
Main jet first
Midrange
Low end
idle

If running pod filters you might need restrictors for the slide. Similar to the air correctors we run in the VM series of carbs when running pods.

http://www.factorypro.com/tech/tech_tuning_procedures/carbtun.html

For bikes over 8000 rpm redline ↓↓↓

http://www.factorypro.com/tech/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

I've followed the above with excellent results.

one thing I learned first hand... if you think you have a carb problem, check the ignition. In my case, I had both problems. Needed air correctors and a new ignition pickup... Now, I haven't needed to install air correctors in CV carbs as of yet. They're not as fickle as the VM carbs when installing aftermarket filters.

[Don R]

More than once I've found jets enlarged either on purpose or by enthusiastic cleaning with drills or torch tip cleaners. The number on the outside of the jet was left intact. Also, aftermarket jets can't be counted on to be correct.