performance question

[Alan1982XJ]

1982 xj1100

I am worried about my bike but since I have no sure idea I will just ask.

Running the bike and the motor will naturally get hot. Ran the bike for a few minutes and the right side of the motor and headers will still be warm to the touch while the left will burn a finger.

So I wonder. Does the bike open up the other two carbs at higher rpms and speed? Or am I only running power from one side of the engine?

As I said new rider / owner. So what should I do if this is not the case?

[CatatonicBug]

All 4 cylinders/carbs run all the time. The headers should get somewhere around the area of 250F (enough to blister a finger) when idling for a few minutes. These engines will often be able to run while 1 or 2 cylinders are not firing properly (or at all). I would start with removing one of the spark plugs from the cooler cylinders, re-connect it to the plug wire, and set it on the outside of the engine block. Crank the engine and look for spark. The coils work in pairs (1&4 and 2&3), so if both cylinders of one of those pairs are the cool ones, it might be a coil issue. If the issue is not with those pairs, it may be a carb issue.

[Alan1982XJ]

To expand, the right side 3 & 4 are warm but not hot. 1 & 2 a re running temperture. However I wouldn't be able to tell if the heat is coming from just one cylinder 1 or 2 or both. But 3 and 4 are deffinetly warm and not hot ( Touching both header pipes )

It's also audibley noticeable out the back of the back in the exhaust. So I will try the method tomorrow you suggested and post here what I find.

On the bright side, gotta pull the carbs anyway for a cleaning and hose replacements.

[CatatonicBug]

Yeah, if you haven't pulled the carbs to clean them, that should be your first step.

[DGXSER]

You might try checking for a kinked fuel line, or if on the side stand, just low fuel in the tank. on the side stand, 3 and 4 petcock is uphill from 1 and 2 petcock. Just the other day mine did this, turned the petcock to reserve and she smoothed right out. Either way, this sounds more like fuel supply issue than carbs to me. However, it is never a bad idea to know how clean your carbs are or are not.

[SFerinTEXAS]

Are you still using the octy valve? Fuel lines in to a vac unit then to the carbs?

[SFerinTEXAS]

If the octy valve is in place then only one side of the tank will feed all the carbs, GRAVITY a good point to keep that function. Its a pain but useful.

Trying to help new people. aint that why we do this?

[SFerinTEXAS]

Have to add this.. If you haven't pulled and cleaned the carbs.. you will

[Alan1982XJ]

The balance of fuel in the tank theory is one I can't wholly put faith in for this instance for two reasons. The first being this is something I have noticed since I started riding / working on the bike and two. Today when I pulled the headers / exhaust for new set it sat on flat ground on the main stand for a good 6 hours.

so tomorrow or the moment the sun comes up whichever I am going to yank the carbs and check the fuel lines proper. Something I needed to do anyway.

I don't believe it is the stator since a previous post said they go in groups 1 / 4 and 2 / 3 so the lack of heat from 3 and four couldn't be a coil issue could it?

Will check plugs, carbs, fuel lines tomorrow. Anything else you guys can think of? Thanks again to all of you as this site and the folks on board have made my life with my first bike all that much more excelent. Even meeting up with a member tomorrow for some freebie tires! Woot

[DGXSER]

If it does it on the centerstand, then yes that should eliminate low fuel issue.

The octy valve could cause it, but for only one side not to feed is rare.

My best guess is still a kinked fuel line somewhere. look it over carefully from the petcock on down for any pinching.

Other than that, your petcock could not be feeding. Get some clear hose to hook to the petcock and run it to a fuel can. Open the petcock and see if it flows freely.

Again, dirty carbs can be an issue, but typically do not show up in pairs like this.

[xs11lover]

I'm just wondering if they get hot at a higher rpm. Maybe it's just a clogged idle jet or two?
What happens when you turn the petcock to prime? That will bypass the octy.
I'd think clean carbs would be step one no matter what.
If you don't have spark when you check the plugs, pickup coil wires would also be a good place to look. I've seen far more broken pickup coil wires than bad ignition coils.

[cywelchjr]

I'm just wondering if they get hot at a higher rpm. Maybe it's just a clogged idle jet or two?
What happens when you turn the petcock to prime? That will bypass the octy.
I'd think clean carbs would be step one no matter what.
If you don't have spark when you check the plugs, pickup coil wires would also be a good place to look. I've seen far more broken pickup coil wires than bad ignition coils.

Ignition would cause a problem on 1 and 4 or 2 and 3, not 3 and 4 and reported. 3 and 4 would be more likely to be fuel related and possibly fuel DELIVERY since 1,2 and 3,4 are fed together. Lack of fuel could cause lack of power on those two, but incorrect jetting could also, so, first checking fuel delivery would be key, followed by cleaning and adjusting the carbs.

[xs11lover]

I understand that, but the pickup coil wires could happen on any of them and they are easy to check. I'm not even sure how to check a ignition coil.
Turning the petcocks to prime would bypass the octy if it wasn't functioning.
I'm just trying to add things to look at are easy.

[cywelchjr]

I understand that, but the pickup coil wires could happen on any of them and they are easy to check. I'm not even sure how to check a ignition coil.
Turning the petcocks to prime would bypass the octy if it wasn't functioning.
I'm just trying to add things to look at are easy.

Sure, they can of course. But my point along with others point is that those problems WILL be on 1 and 4 or 2 and 3, NOT on 3 and 4, not possible as the cylinders in question are fired by opposite coils (both pickup and ignition).

If 1 and 2 are running nice and hot, and 3 and 4 are running cool, the ignition system would be the LAST place I would check, after ruling out the fuel system.

[XS1100_OEM4ME]

Octy

If the octy valve is in place then only one side of the tank will feed all the carbs, GRAVITY a good point to keep that function. Its a pain but useful.

Trying to help new people. aint that why we do this?

Not what i have found with my "octy" There are 2 lines that lead into the octy and 2 lines that lead out yes, but the octy has "one" chamber where they meet, so if ether is feeding the octy chamber, both carb sets are getting the same flow "Prime" on the other hand bypasses the octy and could cause a left/right side differance in flow, are you on "prime" or "on" at the petcocks