lhaolpa
XS400 Junkie
When you rapidly decelerate,the motor should quickly drop speed,thus the "jerking"you're referring to.If you have a leak or other idling problem,the throttle will not respond quickly enough,and not "jerk"on deceleration. lha
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Ya, I'm starting to think I'm the problem. 
I guess it is just a little touchy. If I am very careful with the throttle the jerking is minimized.
Otherwise, everything else is working pretty well. Once my new mirrors come in and I get some of that rust off I think it will be a pretty nice bike overall.
TrueG
I guess it is just a little touchy. If I am very careful with the throttle the jerking is minimized.
Otherwise, everything else is working pretty well. Once my new mirrors come in and I get some of that rust off I think it will be a pretty nice bike overall.
TrueG
This past weekend I decided to try my spare set of carbs again. I took a closer look at the main jets and I could see that the smaller jet was on the right instead of the left, so it appears that I did indeed swap them by accident. 
I also went over them thoroughly again (made sure they went "clunk", cleaned out every jet and passageway and cleaned out enrichment/choke passageway).
The first time I put them in, the left float must have been stuck because I was only getting fuel to the right chamber. So I took them off again, checked them, put them back on and they worked perfectly.
This weekend I am going to try and sync them using the two bottle method (as described here....)
TrueG
I also went over them thoroughly again (made sure they went "clunk", cleaned out every jet and passageway and cleaned out enrichment/choke passageway).
The first time I put them in, the left float must have been stuck because I was only getting fuel to the right chamber. So I took them off again, checked them, put them back on and they worked perfectly.
This weekend I am going to try and sync them using the two bottle method (as described here....)
TrueG
tyrone thompson
MwG R3VENGE
Hi, I'm a fairly new member as well. I have the same bike (black) and I am in the process of restoring the bike to original operating condition. I purchased the bike new in 85,it was my first real piece of Credit in the world. I drove it for years and when I got a car a put it in storage. Last time it ran was 10 years ago. I did not store it properly, did not drain the tank etc. I did drain the oil and periodically put a teaspoon of oil in the plug holes but that's was all. 1 month ago I decided to get her going again. Power,spark, cranking over smoothly are all good, but the carburators were a different story. Because I never drained the fuel,it gummed up everywhere. So I had to completely rebuild them with new oem parts. Most of the carburator parts for your bike are still available. After completely rebuilding the carbs and testing them for vacuum leaks and pressure testing I am now ready to fire her up, just waiting on one washer for the oil filter. To get your Maxim running 
again, you must first have a clean Air/fuel delivery to the engine, once all that's been done, the engine should fire and probably idle roughly but, enough so that you can fine tune the fuel mixture screws and smooth her out to a nice idle 1,200_1,400 rpm. The carburators,more specifically the jets may be clogged, most likely the pilot/idle jets. That's were you should start. Before you preced any further,you may want to go on ebay, and look for a set of JIS screwdrivers. The reason your having problems with the screws wanting to strip is because your using the wrong type of screwdriver. The screws are Japanese Industrial Standard types (JIS), hence the need of an appropriate screwdriver. A word of caution, if you are able to get the bowls off, you must use some type of break free spray to loosen the jets. Also you must use the correct Flat head to remove the jets which are made brass and are very soft, if you damage the head of the pilot jet,it is almost impossible to get it out and the carburator will only be good for parts. Use only oem or equivalent parts,anything else will be a headache, Good luck .
again, you must first have a clean Air/fuel delivery to the engine, once all that's been done, the engine should fire and probably idle roughly but, enough so that you can fine tune the fuel mixture screws and smooth her out to a nice idle 1,200_1,400 rpm. The carburators,more specifically the jets may be clogged, most likely the pilot/idle jets. That's were you should start. Before you preced any further,you may want to go on ebay, and look for a set of JIS screwdrivers. The reason your having problems with the screws wanting to strip is because your using the wrong type of screwdriver. The screws are Japanese Industrial Standard types (JIS), hence the need of an appropriate screwdriver. A word of caution, if you are able to get the bowls off, you must use some type of break free spray to loosen the jets. Also you must use the correct Flat head to remove the jets which are made brass and are very soft, if you damage the head of the pilot jet,it is almost impossible to get it out and the carburator will only be good for parts. Use only oem or equivalent parts,anything else will be a headache, Good luck .
Gra900
XS400 Addict
Recommend you keep all the old jets, unless u r 110% certain that new ones are good
Let us know how it goes when gasket arrives
Let us know how it goes when gasket arrives
Make sure to get real mikuni jets. The ones that have the square within a square marked into them. All others are junk. Sizes are not accurate and a lot of them have bad manufacturing errors in them. jetsrus.com has real ones for good prices.
