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8k rpm at idle!! WTF!
- Thread starter Vloukole
- Start date
Please help?!
Only other problem is that my spark plug (right side) is leaking a tiny bit of air. 
Recreateme
XS400 Addict
This might be a dumb question but did you properly adjust the throttle stop screw?
XSLeo
XS400 Junkie
Plus 1 on the adjust the idle speed.
Leo
Leo
Found the problem. The throttle cable was pinched and was opening the butterflies. Haha. Now I cant get it to idle. The thing is one of the idle mixture screws head is stripped and I can not remove it. I tried using an easy out and the screw driver technique. Will I be able to sync the carbs to a point where I can ride it with no problems? Thanks for your previous reply.
Recreateme
XS400 Addict
Again, you should set the idle screw properly.
Pull the choke, start the bike and it should idle.. if not turn the screw in until it does. Let it warm up and then when its warm push the choke in and if it idles way to low turn the screw in until its idling around 1200-1500 warm... (which means it may need the choke to warm up)
What kind of bike is this? My mixture screws are thumb screws i can turn with my hand alone.. Are you sure you aren't trying to turn the wrong screws?
Pull the choke, start the bike and it should idle.. if not turn the screw in until it does. Let it warm up and then when its warm push the choke in and if it idles way to low turn the screw in until its idling around 1200-1500 warm... (which means it may need the choke to warm up)
What kind of bike is this? My mixture screws are thumb screws i can turn with my hand alone.. Are you sure you aren't trying to turn the wrong screws?
Recreateme
XS400 Addict
This is someone elses image i got off google..
That is the mixture screw you are trying to turn? Even if that top part is stripped you should still be able to grab it with your fingers, or pliers and turn it.. you don't NEED the slot..
Are yours not thumb screws like that? or are you attempting to turn something else?
EDIT: if those are the screws you cant turn, you will have to replace it, you don need new carbs, you need a new screw assembly.. Take your carbs off he bike, spray it with some penetrating lube to loose the threads, grab whats left of it with pliers or whatever and remove the screw and buy a new one (with any other parts you need like washer or springs that were damaged). After this you should clean your carbs again incase dirt or shavings got in them and re install on the bike.
That is the mixture screw you are trying to turn? Even if that top part is stripped you should still be able to grab it with your fingers, or pliers and turn it.. you don't NEED the slot..
Are yours not thumb screws like that? or are you attempting to turn something else?
EDIT: if those are the screws you cant turn, you will have to replace it, you don need new carbs, you need a new screw assembly.. Take your carbs off he bike, spray it with some penetrating lube to loose the threads, grab whats left of it with pliers or whatever and remove the screw and buy a new one (with any other parts you need like washer or springs that were damaged). After this you should clean your carbs again incase dirt or shavings got in them and re install on the bike.
On an '81, the screws are recessed in the hole. The pic above is '79 and older.
If the mixture is OK on the side with the stripped screw, the balance screw (aptly named) is all you need to balance the carbs. The problem is that most of these carbs, especially '80 and newer, are set very lean from the factory.
If the mixture is OK on the side with the stripped screw, the balance screw (aptly named) is all you need to balance the carbs. The problem is that most of these carbs, especially '80 and newer, are set very lean from the factory.
My bike is an 81 and the idle screw is not recessed and it has the oriignal carbs.It should be sticking out like recreateme said.If its not then maybe the carbs have been changed in the past by a po.
The idle mix screw is for air fuel mix. The idle screw it for setting the idle rpm's at idle. First pic is the mix screw witch is recessed in the carb. The second pic is the idle screw witch is under the center of the carbs. I understand his issue and have had the same thing happen to me when trying to remove the caps for the idle mix screws.
Attachments
So will I be able to sync the carbs without being able to turn the right side idle mix screw and only use the carb balance screw? You guys wont believe how stuck that idle mix screw is, penetrating oil does not work.
It depends on where that screw is set at. If it's 1 turn out the bike will be very lean on that side. You could try to put a bigger pilot jet in that carb to compensate but it will be hard to fine tune without being able to turn that screw. You can sync the carbs for equal vacuum but you will still have a lean condition with that bad carb
XSLeo
XS400 Junkie
Pics of what you have will help. Remove the carbs, take some good pics showing them from front and back. Left, right top, bottom.
With these we will be better able to ID them for year and better advise you on how to fix.
Leo
With these we will be better able to ID them for year and better advise you on how to fix.
Leo
This is just one more reason why the '79s and older are so much cooler.
...no pseudo-cruiser rear wheel and seat, the joy of setting points, idle mixture screws that are proudly out in the open....I could go on and on.
...no pseudo-cruiser rear wheel and seat, the joy of setting points, idle mixture screws that are proudly out in the open....I could go on and on.
Yes they are exposed but they also tend to break off in the carbs a lot!! The 80-82 don't break off in the carbs but if the heads get messed up from taking off the caps that cover them
What has happened to him is very rare but can happen. This is why I like the xs360 carbs, side mounted screws and they don't break off in carbs
What has happened to him is very rare but can happen. This is why I like the xs360 carbs, side mounted screws and they don't break off in carbsThe stripped screw head is a big pain but luckily I had another set of carbs that had a stripped pilot jet head and I managed to remove it. Now everything is fixed. Thanx for the help. I will post pics of my bike. Paint job will be done this coming week. (FYI all of the screw stripping was done by the PO! Haha.)
