panzer Posted March 20, 2011 Posted March 20, 2011 First bike, First problem, first post! just picked up a 76 xs360 about a week or two ago, it ran fine, the throttle was a little sticky, so i got new bars for it and when i installed the new bars i lubricated the throttle a bit, the throttle turns very freely now as opposed to how sticky it was before. Now when i turn the bike on it revs up to about 7-8000 rpms. I've tried to do some research on high idle issues, and ive read people saying that the bike running very lean and to adjust the screws, but im not sure if thats the problem because the bike ran fine before i removed the throttle. i know the cable is not binding as i made sure to route it so that it is running freely. any input would be really useful, im not very familiar with carbs in general. thank you!
Moderator drewpy Posted March 29, 2011 Moderator Posted March 29, 2011 try disconnecting the throttle cable and start the bike. if it still revs like crazy, its crap in the carbs making it lean! you then need to strip the carbs down and clean them
panzer Posted March 29, 2011 Author Posted March 29, 2011 try disconnecting the throttle cable and start the bike. if it still revs like crazy, its crap in the carbs making it lean! you then need to strip the carbs down and clean them the bike was running great prior to me touching the throttle, would it be possible for something to suddenly happen in the carb to cause it to run lean? and any great carb information places on the net? im only 19 this is my first carbed vehicle. but i will try that!!
Hornix Posted March 30, 2011 Posted March 30, 2011 Sounds that you don't have the right cable. I think the inner cable is to short. When you release the throttle, do you hear a metal tick? (it's the carb turning arm hitting it's idle adjustment screw). Do as Drewpy said, if it idles normal you have the answer. And put the airscrews back to the original position or you'll get lost in a dark nasty place called carbmessedup-city on planet Mikuni.
GMavi Posted March 31, 2011 Posted March 31, 2011 I have a 77 xs360 doing the same thing, and I just put the carbs back on this month after having them professionally cleaned and rebuilt (it was doing this before I cleaned them as well). The idle adjustment screw is in the correct position more-or-less, and the cable is the correct length. My guess is I/we need to tune the "airscrews," though I really don't feel like messing around with something so touchy
panzer Posted March 31, 2011 Author Posted March 31, 2011 i dont see how it could be the wrong cable. and yes i can hear the click which i guess means that its going back to its resting position. where are the adjustment screws for the air mixture? or a diagram for the carbs on my 76 xs360 would be great
Moderator drewpy Posted March 31, 2011 Moderator Posted March 31, 2011 did you connect the vacuum pipe from the inlet to the petrol tap? 3 - 3.5 turns anti clockwise for the pilot screws as they run lean anyway to pass the emissions. you must have an air leak somewhere.(thas if you have totally isolated the throttle cable as cause)
panzer Posted April 1, 2011 Author Posted April 1, 2011 did you connect the vacuum pipe from the inlet to the petrol tap? 3 - 3.5 turns anti clockwise for the pilot screws as they run lean anyway to pass the emissions. you must have an air leak somewhere.(thas if you have totally isolated the throttle cable as cause) which is the vacuum line going from the inlet to petrol tap? not sure what you mean by petrol tap
Moderator drewpy Posted April 1, 2011 Moderator Posted April 1, 2011 which is the vacuum line going from the inlet to petrol tap? not sure what you mean by petrol tap if you put your location under your avatar I might be able to word it differently! it the device for letting/shutting off fuel from the tank
panzer Posted April 1, 2011 Author Posted April 1, 2011 if you put your location under your avatar I might be able to word it differently! it the device for letting/shutting off fuel from the tank haha sorry, i googled petrol tap and figured it out, the vacuum line leading from the right side carb was good, but there was a vacuum plug on the left side carb that was rotted to nothing, alot of air was being sucked in, so i got a new plug and then i also disconnected my throttle cable and fired the bike up and it idled perfectly. i lubricated the throttle again and put it back together and it seems to idle higher ~3-4k. i have my stock bars flipped over and im starting to think that the position of the bars is affecting the way the throttle cable sits. anybody have the stock bars flipped over? if so did you have problems with you throttle cable? thanks for the help though drewpy you led me to the vacuum leak i was having
GMavi Posted April 5, 2011 Posted April 5, 2011 found a link to all the schematics you should need for a 360 - http://www.bikebandit.com/houseofmotorcycles/1976-yamaha-xs360c/o/m8250 Hope it helps
Kelvin Kathel Posted June 25, 2011 Posted June 25, 2011 I know it has been a couple months since the last post, but I just changed the bars and throttle on my 360 a couple weeks ago. I put on some new clubmans similar in shape to flipping the bars upside down. It was simple and pretty much plug and play. I had no trouble besides getting at the connection where the cable connects to the engine. If you are having problems with it reving fast, only thing I can think of is checking to make sure nothing is keeping the throttle from going to the idle position. Make sure the cable is the correct length and positioned correctly in the throttle controller. Lube and clean any parts that don't move freely. Hope things worked out for you.
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