I bought my dad an XJ but . . .

Okay, so, my dad liked my bike so much that I bought him an XJ550 Maxim for his birthday. It ran great when I picked it up, but after two hours in a trailer I gave it to him and, of course, it isn't running properly.

The problem is that it won't run unless the choke is on full. Even then, it runs erratically. I know that it wasn't like this when I picked it up because the PO had taken it out for a ride before I picked it up and I rode it around his cul-de-sac and into the trailer.

Yesterday if you tried to take the choke off at all, the bike would die immediately. Today, you can get the choke off maybe a quarter, but it is sputtering the whole time and eventually dies. It'll run without the choke for a bit if you rev it up first and then take off the choke, but it will still die after five to ten seconds.

I checked the plugs by pulling the wires while the bike was running (full choke of course) but they all seem to be firing. We set the petcock to Prime to see if it was vacuum related, but there was no change.

We're going to change the plugs, oil and filter since it can't hurt. Any suggestions as to what we should try next?

Edit:
I just read a thread about being shocked by the spark plug caps while the bike is running. I know that my bike will give a bit of a shock if I touch the cap and another part of the bike. When I was checking the plugs on my dad's bike yesterday I was getting *seriously* shocked by only touching the individual caps or wires. I mean, it was really a struggle to maintain a grip on them. I just attributed it to being sweaty, but now I'm wondering if this could be part of the problem. Did a connection bounce loose while it was on the trailer?

Thanks.
Eric

 

If it runs on the Enrichment but won't if the Choke is Closed... and, WILL if you Open the Throttles and get Off-Idle and on to the Main Jets ...

You should try:
Screwing the Idle Adjustment Rod IN a bit.

If that don't help it ... you have to find-out why your Pilot Jets aren't hackin'-it!

You might have dislodged some foreign matter that found its way to the Carb Fuel Bowls.

If everythings the same as it was ... you probably should Clean the Carbs and install a good inline Fuel Filter.

You have a situation that sounds suspiciously like contaminated Fuel messing-up the Pilot Jets.

But a bike that will Run on Choke and Open Throttle but won't or dies rather than Idle has a glowing neon arrow pointing to the Pilot Jets and Passages.

I wish there was something else rather than a good thorough Carb Cleaning to get you straightened-out.
But, I fear that ... that is what is going to have to be done before you get to zooming around with your Dad anytime soon.

 

Thanks, Rick. I had actually mentioned to my dad that very same suspicion; I didn't bother to tell him what would be required to remedy the situation. I was also hoping that I was wrong.

Well, I guess I'll try that idle screw and hope for the best. Keep your fingers crossed.

 

yeah, I get zapped when I unplug spark plugs while the bike is running too. It happens on the ATVs also. I don't think this really points to a problem as much as it points to the fact that you have a good voltage there.

 

Okay, Rick, let me give you a bit more info and see what you think.

First, I forgot to mention that the bike is an '82. The PO bought the bike from a dealer a year ago as a starter bike. He has since bought a new bike and the XJ mostly sat since then. It has only 7933 miles on it. The bike definitely has a short somewhere based upon the shocks I was getting from the plug wires and the fact that the main and headlight fuses were both blown and wrapped with aluminum foil to complete the circuits. Any guesses as to the most likely culprits to check first?

I was filling my dad in on your post when I had a thought. Before we tear apart the carbs, I want to try draining all the gas from the tank, running the bike to burn off the remaining fuel from the bowls, then adding the ever popular formula of gas and Seafoam to the tank and running it a bit to fill the bowls and generally coat everything and letting it sit.

My thinking on this is that this 25 year old bike most likely sat in storage for most of 24 years, no doubt with gas in it. The PO told me that "the dealer tuned it up and sold it" to him last year; I seriously doubt that the dealer cleaned the carbs especially since I believe that the PO only paid a few hundred dollars for it. So I'm guessing that there is/was 20+ year old varnish in the carbs.

Along comes the PO last year, buys the bike, rides it for 1500 miles (His estimate.), then buys a new bike and lets the XJ sit until I buy it. Meanwhile, the ethenol in the gas has been absorbing water, becomes acidic, and starts dissolving/loosening the deposits in the carb and they work their way into the jets.

My hope is that the Seafoam treatment will completely dissolve these deposits, clearing the jets, and preventing us from having to take apart the carbs.

Does this sound even remotely reasonable, or should I simply resign myself to tearing down the carbs?

 

It doesn't hurt to try the Seafoam treatment, however I am willing to bet you will be in there cleaning the carbs anyway. I have had great luck with Seafoam in the oil to clear my sticky starter clutch issue, but it didn't prevent me from having to remove the carbs to get it to run right.

 

you could always drain the carb bowls - see what crap comes out... there is a screw on the side/bottom of them... put a pot under the drain spout, loosen the screw, and let it drain for a 30 seconds or so. See what comes out.

 

I doubt the PO could have ridden it after all that time laid-up without a Carb Cleaning.

Aluminum wrapped fuses points to an Electrical Problem; too.

If everything else but the Fuse Panel and the Carbs seem to be OK ... I'd recommend installing a reliable Fuse Panel and doing the Carbs.

SeaFoam? I don't know. Maybe if the time element weren't so long. I have to suspect the Gas Tank has gook in it and the Petcock is fouled and that something made its way to the Carbs.

It seems to me that your Hand is Dealt.

You have a Tank to Clean and Flush
A Petcock to inspect and Clean
Carbs to Clean
Fuse Panel to replace.

It's a good bit of work, I know ... but, how can you ignore what are obvious situations to rule-out or rectify.

 

I was just reading an article in one of my boating magazines about the problems associated with the ethanol blended gasoline. Since I don't know how long this gas has been in the bike (But it's been long enough that the chain links have some rust on them.), I'm wondering if phase separation may have occurred and the bike is sputtering on the combination of gas with intermittent ethanol/water mixture. I'm thinking that it may have been below the level of the fuel pickup, but the bouncing in the trailer mixed it up with the gas enough that when we unloaded and started 'er up this wonderful mixture was pulled into the carbs.

I know that I'm grasping at straws here, but in any case I've told my dad that the first step has to be to drain out all of the gas. Start with the least painful first and only work up to utter carb agony if absolutely necessary.

 

Mine did exactly the same thing. When I brought it, it was running ok but after fooling around with the carb, the bike wouldn't run as well.

The idle circuit was clogged on two (at least) of carbs. The pilot jet nozzle size is smaller than tip of needle so it's easy for it to become clogged.

So, go ahead and clean the whole carbs. I know it's a lot but once you finish the first carb, you will feel more comfortable doing the rest now that you know how things go together.

After you finish cleaning everything, be sure to bench set the carb (at least). There are info on how to do this in FAQ forum.

 

You're between a rock and a hard place.
After weighing everything you've had to say ... it looks like you are "Damned if you do and damned if you don't" do those things.

I's say the "Time" element puts you beyond a quick "SeaFoam Job"

Cut the Fuse Panel out and install four inline fuse links.
That's going to solve that problem until you pit-in a block if you do.

You have to Flush and Clean the Tank, Petcock and do the Carbs.
Unfortunately, that's life for a bike that had a long nap and wakes-up years and years later.

In the long run you'll be better off.

 

I know that you're right, Rick; but you can't blame a guy for trying.

It's just really frustrating, especially since it ran fine when I picked it up. I wanted to give my dad a fun ride, not yet another project.

 

You got a Saturday of work ahead of you with the old man for a ride on Sunday. Not too shabby a way to spend some quality time with family. Roll up the sleeves, got to it.

 

So the real question is "How much money did you spend to be in this situation?"