apathetic

i built one of these but only realized once i tried to hook it up to the intake nipples that the tubing i used was slightly too big =[

thank you sir for the information i will go check it out i believe that my inlet rubbers are in good condition so i will start with the air screws then check for leaks then check the inlets again if i run into more problems ill be back if it fixes everything ill be back to thank you again anyway THANKS AGAIN!!!

when i start my bike (77 xs360) i dont usually have my choke on all the way if i do, it take it to about under half as soon as i get the bike started as the bike warms up, the idle may rise slightly but as soon as the bike is warmed up and i take to choke off all the way the idle slowly rises to about the 3k range any ideas? thanks for your time and thank you drewpy for your past help and ill thank you ahead of time and your help on this matter

anybody? that rd350 motor in the mito125 in the gallery is awesome...

on my xs360 the right one has a tube plugged with a screw and the left one goes to the petcock (vacuum operated...) i dont believe it makes a difference which one goes to the petcock i do believe at least one has to go to the petcock the other should be plugged otherwise i believe that cylinder would get a leaner mixture than the other

thanks again for the help drewpy yeah i was the one with the carb problem but i think i almost fixed it after i reinstalled them the last time after i "fixed" them i didnt get a chance to try to start it for a couple days when i finally got a chance a couple days later, it started on one kick on a cold motor!!! it still had the problem though... my next steps are a carb sync, points/gap, valve adjustment but a friend pointed me in this direction, the petcock, fuel lines, air filters... so i figured id give it a try if i have anymore questions, ill ask as always THANK YOU AGAIN

i made a crude sketch of my fuel lines a friend took a look and said it may be wrong i tried comparing it to a picture in my haynes manual in the manual you can see a line going directly from the petcock to the left carb but you cant see anything going to the right carb he asked my why there is a Y splitter and if there were originally 2 petcocks possibly on the original tank (as if my tank is not original... im not sure though) the fuel line for the left carb is pretty short and flows easily at a downward angle towards the inlet but the fuel line for the right carb come out of the other side of the splitter and actually runs at an upwards angle (against gravity) this is not really portrayed in the sketch but the longer distance needed for the gas to travel to the right carb, as well as the fact that is has to go up and over the left carb to reach the right carb inlet could be a potential source of problems the left intake manifold nipple is connected to an inlet on the petcock im pretty sure its for the vacuum operated petcock so that it only feeds gas when there is vacuum... the right one is plugged the a vacuum hose that has a screw on the end of it is it possible there should be 2 petcocks? is it possible the the petcock should have 2 outlets for gas (i have 1 for gas and 1 for vacuum) can anybody point me in the right direction please? thanks again for your time

i recently came to this forum too i just got my first real bike, a 77 xs360, so i am in a similar position as you you may want to use a compression gauge to make sure they have equal compression you sound like you know whats going on you may also want to get new points and set the gap check the wires too if your bike is like mine and you need to replace the wires, you have to cut off the old ones and splice in new ones it was actually very easy and simple to do... but only if you have to... you may also want to check into getting a new condensor and also adjusting the valves (i havent done this yet myself, but from what i hear its rather easy) not a bad idea... first you can just take the carbs apart and clean them yourself make sure not to use carb cleaner on any of the rubber parts or gaskets then you can adjust the sync eventually if you have to if your carbs are like mine, it is a little screw on the rod that connects the throttles ebay has been my major source so far. a local bike store had some odds and ends... thats where i got the wires and splicing equipment, they also had a new throttle cable when mine snapped... here is a link to a site that seems like it has parts but i havent used it myself http://www.oldbikebarn.com/motorcycles/Yamaha.php i also recommend getting a shop manual i got a haynes off of ebay for $25

i heard somewhere that the xs360 is based off of the rd350 frame does anybody here know whether or not an rd350 2 stroke will fit into a xs360 frame? i saw that mito350 and its awesome, but newer 2 strokes are illegal in my state, and i like my xs and dont want to get an rd

wow... youre awesome! thank you!! i guess ill take my carbs off, again...

this more accurately portrays my bike, although i still love the bitch im having a lot of fun working on her and im learning a lot but it would be nice to be riding her too

ok now that the weekend has arrived i once again have time to work on my bike i spent what little time i had this week getting more familiar with these carbs i can basically rebuild the entire thing now with my eyes closed although that doesnt necessarily mean i know what each part does anyway i cleaned the entire thing as well as i could on my own while inquiring where i can send them to be sonic cleaned if need be i woke up early this morning and put the carbs back in and i just got back and had some time to tinker with the bike basically i had initially opened the throttle screw until the butterflies were closed that way i could tighten them (therefore opening the butterflies) little by little until i found the perfect idle initially the bike did not start at all (with closed butterflies) eventually when they opened up enough i still encountered the same ongoing problem the bike just revs to 4k and stays there it idles better with the choke partially on but thats no way to run a bike all the time so this is what i did i took the spark plugs out the left one was black (too rich) and the right one was gray (it is my understanding that this is a good thing) i cleaned the plugs and then i counted how many turns of the pilot screw it took to close the left one and applied the same many turns out on the left one i must have done something wrong because then the right one was black and the left one was gray so i closed them both and opened them up 1 full turn then i started the bike and each time i turned them each 1/2 turn until the bike seemed to rev fine i now messed with the idle screw until it found a happy place now the bike seemed to rev and idle fine so i pushed the bike up the alley to the street (the alley is a hill, this may prove to be an important factor) now i am on a level surface as soon as i turned the bike on it revd to about 3.5k give or take 0.5k i was sad and pushed the bike back to its spot in the alley i dont know why the bike seemed to perform fine on the hill and not fine on a flat surface the only thing i think it could affect is the float levels but i dont know why the floats would mess with the idle then again im not carb genius at this point i believe that it is a mixture problem whether its the position of the pilot screws (which i understand adjusts the mixture, i think closed is lean and open is rich) or the position of the idle screw (although at times it seems not to make a difference and always revs at 4k) or a faulty choke (it seems to work fine to me but once again im not carb genius) through the process of elimination i come to the conclusion that this is the problem can you help me drewpy? /hail /salute /thanks

wow youre great thanks for the help at this point i still am going to try a couple more things before i start ordering parts im going to go buy a gallon of carb cleaner and soak the entire thing for at least 24 hours (minus the diaphrams) my only question is other than the diaphrams, are there any other rubber parts that should be removed? also, i cant figure out how to remove the jets. the floats are easy, and so is the float needle and the seat the float needle sits in. but other than those, i cant find anything to unscrew. what am i missing? i also need to try replacing the points (as soon as i get a right, i have a left) and checking the gap (which i can do now anyway) possibly valve timing too once again, i need to thank you for your help. you kick arse.

hey thanks man yeah its gotta be the carbs im convinced of it the carb mounts seem fine to me at this point im going to go buy a gallon of carb cleaner and soak the sucker for at least 24 hours ill come back if it doesnt work

i just bought a pair of vacuum gauges but i hooked them up and the needle just bounces from one side to the other there was no way to get an accurate reading, or even near accurate reading, with those gauges so i am going to return them, but i still an stuck with unsynced carbs i used wd40 to check for leaks but i couldnt see anything i guess its easier to see pressure (bubbles) than vacuum before i buy a pair of those carb kits, i just wanted to make sure one more time so i dont buy the wrong things. my bike is a 360 and the carb kit is for a 400, but its still the same parts, right? ill try the timing either tomorrow (sunday) or next weekend thank you so much for the help drewpy the problem has to be an issue with the carbs and/or timing im positive of it although i got it running again it still has problems even at idle coughing/choking, hesitation and sticking... but it has to be a carb/timing issue thanks again drewpy, and i await your response on the carb kit

i will try to do this today and i will let you know how it turn out. i actually bought some high temp rtv and made a seal in between the block and the rubber inlets, so i would like to think this is not the problem. where can i find a keyster carb kit? i found this on ebay, but i dont know if it will work, its for an xs400 xs400 keyster carb kit i live san diego, california, if it makes a difference i will do the points gap as soon as i get points. i have two lefts, but i need to order a right. at the moment im going to pretend the valves are fine, i dont want to touch them if i dont have to. im going to go buy a pair of vacuum gauges today to try to sync the carbs, but i have a feeling i wont know what im doing. thank you for your time and help, i will let you know how it turns out.

hello im a noob and i need help any help would be much appreciated i recently bought a 1977 xs360 i rode it home and it gave me no problems the next day it started having hesitation and choking issues while it was in gear and at speed this problem continued to get worse until the bike no longer ran the previous owner told me to replace the spark plug wires and points i spliced in new wires and boots i installed new spark plugs i installed a nos condenser i removed the carbs and cleaned them (although i had no idea what i was doing, i reassembled them correctly, i at least know this for sure) one thing that should be noted is that the one of the needle valve assemblies (the little needle with the spring inside that touches the float) is more springy (stiff) than the other i am not sure if this causes problems or not but i thought it was an important item to mention also when i cleaned the carbs i did not have a manual i just took apart what looked easy to take apart and cleaned it with carb cleaner i am 100% sure i reassembled the carb correctly as i read the manual afterwards and had luckily done all the right steps the bike now runs there are still a number of problems at idle, the motor would rev to 4000 and stick i eventually got it down to 1200 by adjusting the idle screw if i revved the bike, the revs would stick to however high i opened the throttle i somewhat fixed this problem (once again with the idle screw); it still persists although not as bad the real problem is after getting it into gear, i get the same hesitation and choking problem i had before after reading a haynes shop manual, i believe that i have to sync the carbs, but i am not sure the manual has instructions on how to sync the carbs, but they are hard to follow apparently i have to get a pair of vacuum gauges hook one to the hose that goes from the carb to the backside of the petcock and the other to the same corresponding hose on the other carb (this hose is connected to nothing and plugged with a bolt) and then adjust some screw i cant find until both gauges read 5 hg cm while the motor revs at 1200 is what i have talked about a common problem? have i diagnosed the problem correctly? is a carb sync the next step? is there an issue with how i described the needle valve assembly? did i describe the carb sync process correctly? i still need to do the points the previous owner gave me 2 points but they are 2 lefts i need to order a right thank you for your time thank you for your help your time is much appreciated

hello im a noob and i need help any help would be much appreciated i recently bought a 1977 xs360 i rode it home and it gave me no problems the next day it started having hesitation and choking issues while it was in gear and at speed this problem continued to get worse until the bike no longer ran the previous owner told me to replace the spark plug wires and points i spliced in new wires and boots i installed new spark plugs i installed a nos condenser i removed the carbs and cleaned them (although i had no idea what i was doing, i reassembled them correctly, i at least know this for sure) one thing that should be noted is that the one of the needle valve assemblies (the little needle with the spring inside that touches the float) is more springy (stiff) than the other i am not sure if this causes problems or not but i thought it was an important item to mention also when i cleaned the carbs i did not have a manual i just took apart what looked easy to take apart and cleaned it with carb cleaner i am 100% sure i reassembled the carb correctly as i read the manual afterwards and had luckily done all the right steps the bike now runs there are still a number of problems at idle, the motor would rev to 4000 and stick i eventually got it down to 1200 by adjusting the idle screw if i revved the bike, the revs would stick to however high i opened the throttle i somewhat fixed this problem (once again with the idle screw); it still persists although not as bad the real problem is after getting it into gear, i get the same hesitation and choking problem i had before after reading a haynes shop manual, i believe that i have to sync the carbs, but i am not sure the manual has instructions on how to sync the carbs, but they are hard to follow apparently i have to get a pair of vacuum gauges hook one to the hose that goes from the carb to the backside of the petcock and the other to the same corresponding hose on the other carb (this hose is connected to nothing and plugged with a bolt) and then adjust some screw i cant find until both gauges read 5 hg cm while the motor revs at 1200 is what i have talked about a common problem? have i diagnosed the problem correctly? is a carb sync the next step? is there an issue with how i described the needle valve assembly? did i describe the carb sync process correctly? i still need to do the points the previous owner gave me 2 points but they are 2 lefts i need to order a right thank you for your time thank you for your help your time is much appreciated