'85 xj700x Carburetor Troubles?

I just bought an '85 Maxim xj700x. It has the Mikuni bs33 carbs... but the internet doesn't have very much info on these.

I am trying to fix a hesitation issue that I think is related to the carburetor being adjusted incorrectly.

What I've done so far...
1) Cleaned carburetors, blowing everything out, and eyeballing every holes/orifice to verify light shines equally through all 4 carbs.
2) New spark plugs.
3) Reset float heights to 17.5 mm.
4) Bench sync'd carburetors.

Since all this, cylinder 1 and 2 are running lean, 3 and 4 are running rich.

I've adjusted the fuel screw on the top of the carburetors, and nothing is really changing, which brings me to this question. Do I have to adjust the screw that is on the air filter side of the carburetors?

I am unable to find if this carburetor has 2 screws, 1 for air, and the other for fuel. Or if the screw on top of the carburetors acts as both.

 

If you actually reset your floats to 17.5mm you may have changed the wetset height.
There is one screw for air/ fuel and there is a screw for synching. You need to know more - here is your lesson:
http://www.xj4ever.com/inside your carbs.pdf
Then this:
http://www.xjbikes.com/forums/threads/the-secret-life-of-carburetors.14751/

This is extra credit and is fun: (there is a video posted by k-more that shows how things work in a CV carb)
http://www.xjbikes.com/forums/threads/stinkin-pod-filters-xj750-maxim.92370/page-2

 

just 1 screw
you have to do a fuel level wet set of the carbs this link tells you how and has the specs


Setting the fuel levels


then you have to do a running sync of the carbs and adjust the mixture screw
there are a few threads on making the sync tool

one is just a long tube the other style is with 2 jars

or you can buy the tool

 

3 sync methods

How To: Make a 2 bottle synch tool

Old School Method of One Vacuum Gauge Carb Sync


$5 Carb sync tool

morgan carb tune andcolor tune

http://www.carbtune.com/

or
https://www.motionpro.com/product/08-0411

you should start by checking the valve clearances. whats the bikes mileage?

also I recommend ohming out your ignition system to make sure it is in spec too.

 

Okay, so the pilot air jet doesn't need to be adjusted? All 4 are completely bottomed out as of now. I can't find anything that says these are supposed to be backed out "so many" turns.

 

I have not been able to wet set the floats, due to the lack of a nipple on the float bowl. BUT, I was just given the fix to that...

Thank you, This will help me a lot. I see that I can purchase nipples to press into the base of the carb bowl, and add the nipple to do a wet set. This is the reason I have not yet done it.

I saw the threads on how to make the homemade manometers. So I made one a few hours before this was created. Problem is that I made it out of Gatorade bottles. Lmao. I feel dumb, But luckily I killed the engine before it got bad. I am going to buy some glass bottles today and rebuild it. On the plus side, I now have a full gallon of Gatorade.

The bike has 17,002 miles on it. And has been sitting for the last few years. Where would I find the info to check the valves? Everything I find ends up being for the Maxim xj700n.

 

I am going to get dressed and go grab some glass bottles for the carb sync, so I 'll let you know when I get that done.

Thank you all for helping.

 

You've got a special engine there. It's a high performance machine with 5 valves per cylinder. Much more work to check valves on an x, but the interval is longer. Make sure you're getting the info for the 750x, and not the "airhead" version.

 

Here's the x valve check info
http://xjbikes.com/forums/index.php?threads/16298
And
http://xjbikes.com/forums/index.php?threads/29661

 

another site you may want to have a look at that may help you
http://www.maxim-x.com/

 

the pilot jet circuit is what gets adjusted when you adjust the mixture screw.

the carbs have 3 circuits in them
1 the enrichment circuit commonly known as the choke. which is used to start and warm up the bike.
2 the pilot jet circuit which consists of the pilot jet, the pilot air jet and the mixture screw which feeds gas for the first 2k rpm (and continues to.) then the main jet kicks in for the fun

3 the main jet . under (above)the main jet is an asperator tube then the slide and needle diaphram assembly and main air jet

 

So I go by the 750x info? Even though I have a 700x?

I've been to that site, and it has helped, but I am at a point where I couldn't find anymore info on there.

I'm confused. Sorry to be a pain in the rear. There's a fuel mixture screw on the top of the carburetor, and then the pilot air jet inside the throat of the carburetor. This being a jet... is it safe to assume it does NOT need to be adjusted? Should it be as far in as it goes? Again, I apologize. My first time messing with a motorcycle, let alone 4 carburetors on 1 vehicle.

 

Also, I just finished the new Manometer. Made out of large mason jars, blue with green liquid. Looks kinda cool.

 

700x is the stroked version of the 750x due to congress.
maxim x site is just another tool in your box.
the 2 air jets and the pilot jet as well as the main jet go it and get tightened no adjustment to be made

 

online manual for 86 700xs
http://www.xjcd.org/node/1104

 

Thank you very much.

This will help me right now. I set the floats to 17.5 mm, and it would not start without carb spray, it would die right away. Just for giggles, I set the floats to 20 mm, and it starts right up. ( The were all around 22 mm. Before I changed them )

I am in the process to doing the Manometer. I'm trying to figure it out.

 

Okay, so I'm trying to sync the carburetors... Damn this is irritating. At first, jar 1 filled up, and 4 was about a quarter full. 2 and 3 were empty. Now jar 1,3, and 4 are empty and 2 is full. I'm ready to just sell this bike. It's really not worth the hassle I've had.

 

I read somewhere, that a different bike needed to have carbs 1 and 2 sync'd, then 3 and 4, then 2 and 3... I'm going to try that. Remove 2 of my jars, and sync them in pairs first.

 

Okay, So I did 1 and 2 together, 3 and 4 together, and then 2 and 3. Looks good. I couldn't find the EXACT middle, but, I let it sit for a minute or so before I went onto the next. And there wasn't a dramatic difference in the fluid levels.

It is honestly sounding a crap ton better already.

 

The carburetor sync did wonders. All I have left to do now is to adjust the hell screw. Or as others says, the mixture screw. Oh, and to order the carburetor nipples to wet-set the floats. I just went on a 20 mile ride, at one point got it up to 75 and then backed off... Speed limit was 60. Before today, I couldn't get it above 60.

Another question... I've looked for info on this, and found 1 post about it... The shifting speeds. I know most people go by the "sound of the engine" , not the speed. But at about what speed should I be shifting from 1st, to 2nd, and so forth...

The only thing I've found was a guy saying he was doing 80 in 2nd... and 105 in 3rd... ridiculous numbers. I am assuming he was testing his bike to it's limits. If I go by the sound of the engine, I'll be maxed out by time I get to 60 mph. I did test the clutch, 30 mph, shift all the way up, and see what happens. Giving it gas, it will gradually build up speed. Full throttle will speed up the process.

Any help?