KoryGable
XS400 Member
Also, I forgot to mention that I replaced my key ignition with a simple on/off switch. Not sure there is anything to worry about with doing that.
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1982 XS400 - Running on one cylinder ... still.
- Thread starter KoryGable
- Start date
Well, probably not as you are able to get the bike running. If you are comfortable not having the steering lock or parking lights, and anyone being able to ride your bike away... Then it is all good! 
Nope, it's either closed or open, wouldn't possibly cause this
KoryGable
XS400 Member
Well, it seems my knowledge of transistor theory is flawed. These guys didn't check out with the usual diode test, so I ordered new ones. Turns out the old and new have the same electrical characteristics.
I went ahead and put the new ones on the unit and tried to fire it up. I'm getting the exact same results.
I still don't understand why it barely runs on the left cylinder and why its so smokey. Could it be a carb issue? Is it a vacuum leak? AHHH! I'm going crazy.
I went ahead and put the new ones on the unit and tried to fire it up. I'm getting the exact same results.
I still don't understand why it barely runs on the left cylinder and why its so smokey. Could it be a carb issue? Is it a vacuum leak? AHHH! I'm going crazy.
Drewcifer
1976 XS 360 Maniac
1. Remove your carbs, hold a rag near the intakes and spray starting fluid onto it so it enters the combustion chamber. If you get combustion on both sides, the issue is the carb and it's ability to supply fuel to BOTH cylinders. (Check too, that any intake hose barbs for the petcock are either hooked up to tubes, or closed off with rubber dummy cap or sealed section of appropriate width air or fuel hose. Like there's a nipple for the petcock vacuum hose on BOTH sides, and you need to make sure the spare one is sealed closed. If that's off the bike will fire horribly.)
2. Move spark plugs from one side to another. If you get a change, the issue is the spark plug.
3. Do the same with your coils. Label them clearly which is the correct side, see if swapping them helps...
4. Check your valves. If they are badly adjusted the problem will persist.
So if you have a cdi, do you have a trigger coil or pickup coil? I don't know how those bikes work, but I'd check that out. I fixed a triumph that had a similar issue. As the pickup coil failed, one cylinder refused to fire...
Good luck and keep us posted.
Drewcifer
2. Move spark plugs from one side to another. If you get a change, the issue is the spark plug.
3. Do the same with your coils. Label them clearly which is the correct side, see if swapping them helps...
4. Check your valves. If they are badly adjusted the problem will persist.
So if you have a cdi, do you have a trigger coil or pickup coil? I don't know how those bikes work, but I'd check that out. I fixed a triumph that had a similar issue. As the pickup coil failed, one cylinder refused to fire...
Good luck and keep us posted.
Drewcifer
Yes!! a thread that I was about to post is on the first page!
Will be watching this one.
My problems are similar yet with a '79.
Have 2 parts bikes so I've checked and tested 6 different coils and caps. Selecting the best, and the issue persists.
New pod filter and stock drags.
Purchased a set of points after installing one off the (low milage) 360, to no effect. Purchased a set off xschris with no luck. We be told me that they were off a low mileage bike and my cam Lobe may be suspect. Visiblyworn and failed the within spec chek. Replaced it with one from the 360 and still persisted.
Pod filters and stock drags. could never get it to run right so stock jetting. Eventually gonna put my fat pipes on so I bought jets to (in theory) get the tuning correct on them. But that's a whole nother thing. I can't fix one without the other so I too am stumped. Ill be Looking in to diaphragms.
Sorry for the long post, but yeah. I'm confused too
Posted via Mobile
Will be watching this one.
My problems are similar yet with a '79.
Have 2 parts bikes so I've checked and tested 6 different coils and caps. Selecting the best, and the issue persists.
New pod filter and stock drags.
Purchased a set of points after installing one off the (low milage) 360, to no effect. Purchased a set off xschris with no luck. We be told me that they were off a low mileage bike and my cam Lobe may be suspect. Visiblyworn and failed the within spec chek. Replaced it with one from the 360 and still persisted.
Pod filters and stock drags. could never get it to run right so stock jetting. Eventually gonna put my fat pipes on so I bought jets to (in theory) get the tuning correct on them. But that's a whole nother thing. I can't fix one without the other so I too am stumped. Ill be Looking in to diaphragms.
Sorry for the long post, but yeah. I'm confused too
Posted via Mobile
Maxim-umm
XS400 Addict
did you check/replace the capacitors as well?...just an idea...
No, but I have another one to swap it with if it fails. I'll test it and replace as needed.
KoryGable
XS400 Member
UPDATE! I boiled the carbs and I've seen a huge improvement. It took some time get the second cylinder firing like normal, but after a few minutes of letting it warm up, it was running pretty normal. I'm still not sold that my issue has been resolved.
NEW PROBLEM. I have a nasty oil leak. It's coming from somewhere around the chain drive/sprocket/clutch area. Anything I should look for in particular?
Check out the picture.
NEW PROBLEM. I have a nasty oil leak. It's coming from somewhere around the chain drive/sprocket/clutch area. Anything I should look for in particular?
Check out the picture.
Attachments
fuax
XS400 Member
Maybe your float and/or needle was getting stuck, my bike set awhile and had a similar issue, tapping the side of the carb with a hammer a few times fixed the issue on mine.
danisawesome
XS400 Addict
I never heard my bike run before I rebuilt the carbs, but apparently it didn't run very well on the left cylinder. After an ultrasonic clean, spraying out passages, new diaphragms, float needles, main and pilot jets, all gaskets and orings, adjusting the floats, and bench syncing, both sides run flawlessly.
It might be worth it to just go through your carbs really well as it isn't too pricey for parts and can only benefit your bike in the long run.
And I'm glad you got it running well for the moment! Let's hope that dirty carbs are the culprit.
It might be worth it to just go through your carbs really well as it isn't too pricey for parts and can only benefit your bike in the long run.
And I'm glad you got it running well for the moment! Let's hope that dirty carbs are the culprit.
willwright
XS400 New Member
Did you figure out your problem. I'm having the exact same problem and I feel like I've tried everything!
Hi Will, welcome to the forum. Instead of digging up old threads, try to start a new one specific to your issue. Give some info about the bike and about yourself such as motorcycle background, maintenance knowledge, etc.
