Choking up on me still.

[shottothehead]

I've got a XJ1100. From time to time it will coke up on me as though it's not wanting to fire. There seems to be no pattern to it. It has done it right after startup and going down the road. After I've stopped (at a light) it seems to not want to accelerate. It sounds like it's not firing on all cylinders. After I rev the engine it'll be ok. It's becoming harder and harder to start in the mornings as well. It'll backfire and from time to time I even get some black smoke. I took my spark plugs out and as I figured they were black.

Now before I had this problem I had another one. The bike had a strange idle. It would bounce up and down from 1100 to 1500 rpm. I had to keep the choke on to keep it running. This seemed to fix itself. But after this stopped it start into what I mentioned first. Do you think the problems are related?

Where do you guys think I should start to tackle this from? I'm thinking turning the carbs set screws down as the plugs are black. How far should I turn them... and where are they located on the carbs. I've never worked on carbs before so this is a first for me.

Any and all help will be appreciated. Thanks, from a fellow rider.

[GtrMn]

If you haven't done it already....do the "triple clean" carbs thing....reset the idle screws.....resync. Then check the pickup coil wires.

[TopCatGr58]

Well,
First of all, how old are the sparkplugs? Secondly what rpm range do you run in, and is the bike used just for short trips in town or do you put some decent highway miles on it?

What does your air filter look like, if dirty can be choking down the carbs.

You might first try just running some good tuneup in a can SEAFOAM, or Techroline carb/fuel injector cleaner, a few ounces in a few tank fulls and see what happens!

You say you haven't been into the carbs...but has anyone else, shop perhaps?? We need a bit more history on it before we can make better guesses..er I mean suggestions!

And, btw, don't worry about your pickup coil wires, cause the XJ's timing plate is stationary, and so they essentially don't get damaged and worn like the XS's......Gtrmn...you might make a note of this for future reference! But otherwise your advice is also good!
T.C.

[GtrMn]

Thanks T.C. Thought they were the same...I'll make a note of it! Dang differences between the models...

[shottothehead]

Well, I just put new spark plugs in. I thought I'd start there. It's still doing it.
The bike usually settles into 1100 rpms. I most always take short trips. 30 miles at a time at best. I changed the air filter a few months ago. I've used seafoam in the past to give it a good cleaning. Think I should use it again? Does this Techroline carb/fuel injector cleaner Work better than seafoam?
At the beginning of the riding season I had a shop work on the carbs for me. Rebuilt them actually. I haven't had any problems with them since though.
Thanks again for the help guys.

[shottothehead]

Choking up on me still.

I know I just posted this but it seems the thread may have died...

I've got a XJ1100. From time to time it will choke up on me as though it's not wanting to fire. There seems to be no pattern to it. It has done it right after startup and going down the road. After I've stopped (at a light) it seems to not want to accelerate. It sounds like it's not firing on all cylinders. After I rev the engine it'll be ok. It's becoming harder and harder to start in the mornings as well. It'll backfire and from time to time I even get some black smoke. I took my spark plugs out and as I figured they were black.

Now before I had this problem I had another one. The bike had a strange idle. It would bounce up and down from 1100 to 1500 rpm. I had to keep the choke on to keep it running. This seemed to fix itself. But after this stopped it start into what I mentioned first. Do you think the problems are related?

Where do you guys think I should start to tackle this from? I'm thinking turning the carbs set screws down as the plugs are black. How far should I turn them... and where are they located on the carbs. I've never worked on carbs before so this is a first for me.


Well, I just put new spark plugs in. I thought I'd start there. It's still doing it.
The bike usually settles into 1100 rpms.

I most always take short trips, 30 miles at a time at best. I changed the air filter a few months ago. I've used seafoam in the past to give it a good cleaning. Think I should use it again? Does this Techroline carb/fuel injector cleaner Work better than seafoam?

At the beginning of the riding season I had a shop work on the carbs for me. Rebuilt them actually. I haven't had any problems with them since though.

Any and all help will be appreciated. Thanks, Jason

[oseaghdha]

Re: Choking up on me still.

Originally posted by shottothehead
.........................
At the beginning of the riding season I had a shop work on the carbs for me. Rebuilt them actually. I haven't had any problems with them since though...............

Well, maybe.
It's either carbs, pickup coils, or some combination of the two.

[shottothehead]

ok then. What are pick up coils? All the work I'm doing on this bike I'm doing for the first time so, you'll have to bear with me.

[TopCatGr58]

Hey Shot,

Hard starting, and poor low rpm response is most commonly the pilot and starting circuits, and SEAFOAM is about the best IMHO for helping to clean out the junk. You had it worked on, and ran okay for quite some time. Did you clean out the gas tank? Do you have inline fuel filters? Lots of crud in the tank can ruin a newly cleaned set of carbs!

But with the plugs being black/sooty more tuning may be needed anyways!? The XJ's IIRC have been reported to use the newer designed no holes pilot jets, but still problems can occur if the wrong size...possibly due to different brand(K&L) parts kits were used! Incorrect pilot jets have notoriously caused many an Xsive problems with their pilot circuit, and only after they removed and put in OEM or Genuine Mikuni jets did they resolve the problem!

So...screwing in the pilot screws "may" help to lean out the circuit a bit, but if the jets are the wrong size, it'll still be tough to tune!
T.C.

[TopCatGr58]

Hey Shot,

There have just been a lot of threads and posts, and your original thread just scrolled off to the next page! I just merged them, and you can see what I stated about with yours being an XJ that the pickup coils are probably not at fault since on the XJ they don't flex, the timing plate is stationary!
T.C.

[shottothehead]

You know of all the work I've done to it I don't even recall ever seeing a fuel filter... where are these located? Are they in the tank before the petcocks? What are these pilot and starting circuits you are talking about? Are they located in the carbs?
No I didn't clean out the gas tank. I didn't even think about it... I guess I should do that. How does one clean a gas tank? If a dirty tank is the problem I suppose I'll have to get the carbs cleaned yet again.
I guess the next step will be to get a hold of the shop that worked on the carbs and find out what kind of jets were used.

[TopCatGr58]

Hey Shot,

Now is when "we" direct you to look at the TECH TIPS, scrolling down from the MAIN FORUM PAGE, not just the links in the left column!

Maintanence Carb tech tips
Repair Carb Tech Tips
Modifications Carbs Tech Tips

T.C.

[fredintoon]

"You know of all the work I've done to it I don't even recall ever seeing a fuel filter... where are these located? "
Hi Shot,
The fuel filters are plastic towers that stick up from the petcocks inside the gas tank.
Also each carb has it's own little wire screen dome filter that snaps on top of the float needle valve seat.
The petcock filters can fall out and lay loose inside the fuel tank. You will never know they've done it until you switch to reserve and there ain't none because those filters also control the reserve fuel level. Or until your carbs bung up with crud. Best you fit in-line filters to back up the stockers.

[shottothehead]

Extra filters?

It's been a long time since I got to this post. I've been stupid busy at work.

How does one install inline filters to the bike in addition to the stock filters?

[TopCatGr58]

Re: Extra filters?

Originally posted by shottothehead
How does one install inline filters to the bike in addition to the stock filters?

I think you've taken a few too many shots to the head?
Do you watch Jeopardy? This could be one of their Stupid Answers Category questions!

You get an inline filter from several sources, below is from MikesXS

and you cut the fuel line somewhere between the petcock and the carbs, where you can position a filter to fit, flow and not kink the lines. Many folks will run the left petcock lines to the right bank and vice versa to allow room for the filter and line!

No malice intended with above remarks, hope you know!
T.C.