Factory Settings for Mixture.... WOW!!!

I'm curious about the thread ptich. Wouldn't that mean the carbs ( at least in the pilot jet area) would be different. I'm not sure how they would be interchangeable. Anybody got a picture of the different pilot screws or something from Yamaha on this particular issue.

 

I think I am going to be close to 2 turns out for the initial setting start point. My bike always starts right away, so I think it is pretty healthy and even one turn in or out just means I may or may not need to play with the choke more or less. I think I may have an sticking slide on number three
because I didn't adjust the mixture on number three but now the plug is starting to look the same colour as the other three.
My other theory is my bike being a YICS version hs something to do with it, but that is probably not correct. At two turns out I can ride at idle speed or a bit less even up a bit of hill, I couldn't do that at the original just over one turn out setting. I think I am going in the right direction. I'll run a few hundred miles and maybe put in new plugs and start "chopping" again.
Stay tuned !

 

I think we are at the point in time where everyone should be aware of the possibility that their Diaphragm Piston Bores need to be de-oxidized and re-finished.

Just the time factor, alone is sufficient to have caused the Bores to "Ox-up" and diminish the performance of the Bike due to Piston Lag or sticking.

 

First post... I have to say Thank you before anything... I think I am going to learn a lot in this forum...

I purchased my first bike, and I am having some problems with it... I have a Maxim 650.

I have no midrange throttle... It is running really rich... and reading under this topic, "Factory Settings for Mixture... WOW!!!" -- I find myself with a question for anyone with the patients to teach someone who is mechanically inclined but unfamiliar with Motorcycle Carburetors...

I have pulled all four carburetors off, pulled the bottoms and tops, pulled screw in jets and ports soaked everything in carburetor Chem Dip, except the body of the carbs or the rubber parts... Put it back together and put it on the road, It is running better but it is still burning rich... the only adjustment screws I can see are on the bottom of the carburetors... Are those screws the ones you are talking about as the brass plugs? It seems if I loosen those that gasoline will drip out of the bottom of the carburetors... If those are not the idle mixture screws, where are they? My bike is burning EXTREMELY Rich...

Oh wise ones of XJBikes.com. Is there someone out there who can give me some insight?

 

The screws on the bottom are the carb drain screws, the idle mixture screws are on the top. I am going for a wrenching session and will post a picture. Thanks to Rick, I am sure Diaphragm Piston Bores sticking is my problem with number three. Any response to my spark plug colour pics, Ok, or not ?
Eric

 

Adjust screw here (yes, it was raining when I took this picture, the bike and I got very wet ! )

 

You might not see the slot of an Adjustment Screw.
You might see a flat Plug with a dimple in the middle.
To make your adjustments ... that Plug has to come out of there.

Drill it a little bit right in the middle and be careful with the drill.
Theres a SOFT BRASS Screw Head right on the other side of the Plug.
You don't want to damage the Screw Slot with the drill.

Drill it a little bit and then screw in a Drywall Screw.
Grab the drywall screw with Vice Grips and extract that Plug.

Now, you will be able to make Mixture Adjustments.
Oil the Screw.
Don't try and turn it with a regular screwdriver.
Fabricate a screwdriver that fits the slot ... PERFECTLY.
No end-play.

Chances are, over time, the screw is stuck.
Oil the hole and see if you can move the screw DOWN to good threads.
If is moves ... exercise it back and forth ato lube the ultra fine threads.

Once it moves without sticking ... fine-tuning begins.

 

Wow again! Thanks to the two of you! (plansea and RickCoMatic)
I should have this carb problem licked by the end of the week...
I have to go do my real job today, maybe I can get started tonight...

Great pics, and Great Tips.

I will definately share what I learn...

(Rick- Sending a PM.)