Crazy Carbs

I got one for the books. I have an XJ 650 Maxim with XJ900 motor on it. After many tries at the carbs I finally got them set ,so I thought. I put 15000 mile on it( all highway) and finally decided to check valves. They were all in spec but the bike fell at about 7500-8000 RPM. I have a stock box with 4 into 1 Jardine exhaust. I had 107.5 mains in it. I put 110 mains in it but it ran soggy. I put 105's in it but now again I have 2 carbs (#1 and #2) that leak out of the overflow. I did not touch float settings at all. Any Ideas? This is my forth bike and so far the best bike I have owned.

 

My carbs took a while to settle in and I had to pull them down several times to check and adjust the floats... I ended up getting a new set of float valves when I got sick of trying to stop the gas pouring out... Fixed the problem instantly & made setting the levels a breeze

My advise... Keep persevering... I haven't had my carbs in bits for a couple of years now... In saying that, I did have to clean them every 6 months for the couple of years prior to that with no explanation as to why

 

Yea the funny thing is all the carbs have new kits (float valves & gasket) and one of them that leaks has a new float in it ( broke tab on other one). Yea I keep pulling my hair out but would not get rid of bike. Only paid $200 for 650 and when motor locked up in 1st gear got the 900 for $300. Crazy fast & fun to ride. I will try tomorrow to bench set them again. Till then gotta run the drop top to work. Almost the same but without the helmet.

 

Think about finding a see thru glass or plastic container to act as the bowl that you can place under the leaking carb... Fill with gas and hook up a supply to the carbs & watch what's happening and adjust on the fly...

 

Not a bad idea. Never thought of that one. My luck I have float rub on the carb so when I test it with your idea it will shut off... I will make a small plastic container at work tomorrow to try it. Thanks for the help. XJ-er for life!

 

I saw a thread on here where a guy took a round container, heated it and turned it in to a square one which made it fit perfectly under each carb as required

 

Thanks. I will check it out tomorrow.

 

Black Douglas scotch glass...... almost a perfect fit ,and the right shape.

cheers , Murray

 

Got it figured out. Bench set it 5mm. Stuck carbs on bike. Quick fired. sounds smooth. Will finish tomorrow.... Need to ride.. great stress reliever. Thanks for all your help.

 

Got fired today runs out ok up in the rpm range, but part throttle sputters (rich). Will lower floats this weekend and try again.

 

I'd be more inclined to do a carb sync than adjust the floats again...

Changing the float levels is not the way to adjust mixture... Adjusting the air/fuel mixture and needle height is the way to do that, bearing in mind that the screw adjustment only affects the mixture up to about 2k rpm then the needle height takes over

 

If you can rig something up and set your floats wet. Levels too high will give you rich. Too low it will be lean.

I made a jig to hold my carbs so I could IV bottle fuel in and get the floats set with the clear tube method. Nailed it and the bike runs mint. Thats my nice little 81 650 non YICS which also by the way syncd up nicely.

MN

 

Just finished wet setting on bench with squeeze bottle. Set @ 5.5 MM or so. Still ran wet on part throttle. Set needle clip from #3 position & set a @ #2 lean And much smoother now. Will run it tomorrow to work. but as of right now it be blistering fast..

 

May want to try this method. Works great.....
http://www.xjbikes.com/Forums/viewtopic/t=31559.html

 

Now all I got left is too sync carbs. But as of now Floats are at 5.5 MM. Got 105 Main Jets. Needle set on the bottom. Fuel mixture screws at 2 turns out. Bike is blistering fast and smooth. Plugs are 15K & very clean. Fun Bike.