New bike, new to forum, bike that will not idle

So I got all the valve shims checked and replaced as needed. I also adjusted the cam chain. Got the bike back together and started up. I didn't take it for a ride but while sitting in my garage I would I hear what I would describe as a thunk every few seconds. I assume this can only be a bad thing?

 

Did you synchronize the carbs at idle? Two pistons working against each other will cause a thunk. Synch the carbs and that should go away.

You might also be hearing the primary chain slap. The 550 has a hydraulic primary chain adjuster. Raise the idle speed to between 1300 and 1500 RPM to get the oil pressure to the tensioner where it needs to be.

 

Thanks for the quick reply. I have not yet synced the carbs, what I read said to wait until the valves were adjusted. I will need to adjust the float levels too before I sync the carbs, correct?

I'll give raising the idle a shot in the morning and see what happens.

Will I be doing any harm riding it a bit as is before a carb sync?

 

Synching the carbs should clear up some things as k-moe stated.

Gary H.

 

Looking at ordering some turn signals. Will something like these give me any issues?http://www.ebay.com/itm/Set-of-Four...m5b26250711:m:mf40kNHdaRDl-PxlBzcbcDw&vxp=mtr

 

Those will be fine. You may have to change the bulbs out for a higher wattage, depending on what they ship with.

 

Alright, a couple updates. The thunking went away after a short ride. I'm guessing parts just needed oil lubrication.

Turn signals ordered. Replaced tail light and brake light with led. Considering doing license plate light too, but not sure if this would really be worth it as far as energy savings go? If I did go with replacing this for led, what size bulb is it?

Taking the bike to a friends house next week to sync the carbs. Ordered a yics tool (I know I could have just made one). I also ordered a compression tester. Next on the order list will be rear brake shoes and brake lines.

Do I need to buy a color tune plug?

Center stand question, I installed the center stand, and when I put the bike on it I feel like it is going too far forward. This results in the rear tire still touching the ground. The bike also slightly leans to the right. Did I do something wrong in installation, or what is going on exactly?

My speedometer needle vibrates. Not so bad that I can't tell how fast I'm going, but bad enough to be annyoing. Any ideas on what to do to try and fix this?

 

Oh and one last question for tonight: the PO told me he disconnected the brake light from rear brake pedal. Don't know why. How/where do I reconnect it?

 

My speedometer needle used to vibrate before I cleaned out the speedometer and re-oiled the cable. It is rock steady at this point.

 

I can't speak to the XJ, but when I converted my scooter to LED lamps I freed up 4 amps. That was enough to be confident in running a GPS off of the battery without worring about overworking the altenator (not really as much of an issue for an XJ). In order to save amps you do have to avoid using load resistors though. That will mean you will need a no-load turn signal relay if you do LED turn sognals, and that will mean wiring in a second realy to keep the auto-cancel feature. Just changing the tail lamps, and dash lamps should save you quite a few amps that you can use for other things. I think the licnes plate lamp is a T-2, but pull yours to be sure.

The center stand looks right as far as angle, but it looks short. Are you shure that it's for your machine? Give us a pic (or three) looking up at the mounting points.

The speedo needle is likely jumping because the seppdometer cable needs to be lubricated or replaced. Take it off, pull the cable from the sheath, clean it, and re-grease.

The color tune plug helps, but you can tune without it (just takes a lot longer). The YIICS tool is (IMHO) not necessary; spend the money on the color tune instead.

The rear brake switch is located on the left of the bike, along the rear frame upright, just above the brake pedal pivot. If he disconnected it it's likely due to a misadjusted or broken switch.

 

Cool, I think that I will pull the speedo tomorrow or Tuesday and replace the bulbs with LED and then lube the cables.

I'll get some pics in the morning of the center stand mounting points.

I figured out the rear brake switch. I found that the PO had disconnected it by adjusting the switch all of the way out, putting the most tension on the spring. So actually this should have engaged the light, but it was doing the reverse. I disconnected the spring and the switch closed, and on went the light. So I pulled the switch apart and blew it out with compressed air. Then I traced the wire and found a loose crimp connection. Put everything back together, after plenty of fiddeling with the wire leads that contact the metal piece in the switch to get positioned correctly, and everything seems to work fine. I'll keep my eye on it for a couple of days to make sure everything is good.

Thanks!

 

Here is a pic of the center stand mounting points. I notice on my side stand that I have two springs, an inner and outer. Should I have 2 for my center stand as well? Because I only have one.


I'm off to set my float heights, as well as repair some intake boots.

Freedom ain't free.
Happy Fourth.

 

The center stand only has one spring. I can't quite tell from teh pic, but is there a stop on the left side of the frame?
How square is the stand?

 

You want to heat the engine case, not the bolt- the aluminum expands faster than the steel, and it will loosen the corrosion in the hole. Alternate between soaking with PB and heating- the heat will draw the PB in. You'll get it, just have to be patient and work at it.

 

Bike wouldn't start this morning. Pressing the starter button does nothing.


Battery fluid is in range. Battery reads 12.4 volts.

Jumped the solenoid, and the starter engages. Is my issue the starter button itself? Or wiring somewhere? What should I try next?

Thanks

 

Could be. Did your bike (in neutral) actually start when you jumped the solenoid. Battery should read 12.6v or slightly higher after a full charge.

Gary H.

 

I replaced the 20 amp main fuse and then it started. What should I do to find the cause?

 

Nothing unless it blows again. Fuses can fail from age (or vibration) just like anything else.


Actually let me walk that back a bit. You should go through and inspect the entire electrical system (cleaning oxidation from every contact), but as a matter of course, not because the fuse was blown.

 

it's blown twice.

 

Start checking wires all through the system, beginning with the main circuit.

 

Check all grounds, and any point in harness around under the tank. You could have a bare spot and it intermittently touches ground.

 

on 750's there are three ten amp fuses and a thirty amp main, are you sure twenty is right?

 

He's working on 550.

 

550 amps are the same as 750 amps, the branches should add up to the main

 

But the 550 and 650 have 20 amp main fuses, not 30.
See the catalog, first post: http://xj4ever.com/catalog/d-3-fuseboxes.html

Remember that the 750 has extra electronics. The branches do not need to add up to the main unless all the branches are expected to run at full current simultaneously, and should not add up to the main unless the wiring in the main circuit is sized to handle that load.


The OP has a main circuit that is rated at a maximum of 20 amps, and is blowing a fuse because of a short, or a component that is drawing too much current for some reason.
Put a 30 amp fuse in, and that short could turn into a fire.

 

well then don't do that, just buy a big box of twentys.
it would help if we knew when it blows, like instantly, or when you turn the key, or after it runs for a while, or when you turn something on.

 

Did the fuse start blowing after making the repair to the rear brake light switch?

Double check his work to make sure the proper circuit has the correct fuse size and placement. If correct the signal fuse should blow before the main if the problem is with the brake light wiring or components.

Here are a couple of links on the 550 fuse box for reference:

http://www.xjbikes.com/forums/threads/xj550-fusebox-replacement.20809/#post-422459

http://www.xjbikes.com/forums/threads/electrical-fuse-box.41848/#post-367960

 

Alright, I think I found the faulty connection causing the fuse to blow. Repaired it, bike ran fine last night.

Went to ride bike today, won't start. The starter is engaging, the bike just won't turn over. Battery is at 12.6v resting, doesn't go below 11.4 while cranking the starter. Recommendations? All fuses are good.

 

The engine won't spin, or the engine won't fire?

If the starter spins, is there a sound accompanying it like a whirr, or like a can of rocks rolling down the driveway?

 

Engine won't fire. I put on the charger for a bit, and then the motor fired for a few seconds before dying. Battery issue?

 

Starter sounds normal when cranking.

 

I was able to push start the bike. This makes me think that it is indeed the battery. I'm going to put it on the trickle charger for the rest of the day and see if it will start later tonight.

 

Maybe. Maybe charging issue as well though.
Check the batery resting voltage (once before you start it up, and again after it's sat overnight).
Check the battery voltage drop when you thumb the starter (it should not drop below 10V).
Check the voltage at the batter at idle.
Check the voltage at the battery at 2,000 RPM.
Check the voltage at the battery at 4,000 RPM.
Report back.

 

Alright, after a few hours on the charger it started. Resting voltage 12.6, cranking never below 11.4.

Voltage at 2k rpm: 13.5
Voltage at 4k rpm 14.4

Bike still doesn't idle great after synching. I still need to do the mixture screws, haven't got a colortune yet.

I now have another issue, one that probably belongs in the "What stupid thing did you do to your yamaha" thread. I noticed that the bolt holding the choke lever was gone. I found a new bolt, apparently too long and screwed in too tight, and now my turn signals no longer work again. I took the assembly apart, and I couldn't see any broken wires or anything that looked very broken. The switch itself feels different now, it sort of sticks.

 

You may have bent the switch.

 

I disassembled again and noticed that the black plastic piece that the three wires are soldered to was broken between the far left and other two wires.

 

Alright I put it on the charger for a few more hours yesterday and took it off before going to bed. When I woke up the voltage was 12.8. Didn't check while cranking, but the bike wouldn't start again. I push started to get to work. While I was at a stop sign at about 1500 rpm the bike died, but was able to start it with push start. Could a weak battery have caused it to die while idling? Should I just go buy a new battery?

 

I believe that your battery is toast, but I would check it while cranking to make sure before spending money on another battery; it can be frustrating when spending money only to find the issue was something else. I know that if the main fuse is disconnected when riding, you have to keep the revs up above idle speeds or the bike will shut off, if the battery is bad, you are kind of doing the same thing, I think: not giving the bike enough power to run. At idle speeds the bike is actually running off battery power from what I understand.

 

I think it must be the battery. I am able to push start the bike, and after the bike is warmed up I am able to start it using the start button. I'm guessing it just doesn't have enough juice when the engine is cold to get it to fire. It's weird though because yesterday when cranking the voltage never dipped below 11.4 volts. Is it possible with a bad battery to be showing good enough voltage but not actually be able to start the motorcycle?

I got a battery tender jr today. I'm going to leave that on overnight and then check the voltage resting and while cranking in the morning. If it does not start, I will go to autozone and have them test it, and probably buy a new battery.

In regards to the turn signal switch, yeah it's pretty well busted. Should I be able to just buy an aftermarket switch? I'm fine with losing the auto cancel (didn't like it anyway). Will I need a new relay too?

 

Get a used assembly off ebay cheap. A lot easier than messing around trying to cobble together something that may not work . Sounds like your battery is weak , what is the level on the cells in battery? Serviced with distilled water ?

 

Levels on the cells are within range. I'll probably top them off tomorrow. After I have started leaving it on the battery tender when I'm not riding I have not had any issues starting.

 

I finally got around to doing a compression test this afternoon.

Procedure:
1.) Ride bike around all morning (errands)
2.) Remove spark plugs
3.) Disconnect TCI
4.) Connect gauge, throttle open, run starter until needle stops going up
5.) Repeat as necessary to confirm result consistency

Dry results:
1: 117
2: 96
3: 107
4: 105

Wet results after squirting some oil into spark plug holes:
1: 158
2: 110
3: 185
4: 150

Compression Specs for my bike:
Standard: 121
Minimum: 100
Max: 135

What do these results tell me? Rings are bad in 1, 3, and 4? Where do I go from here?

 

Check your valve clearences?

 

Checked and adjusted.

 

It could be the tester itself that is off. Do you have a tool rental shop where you could get a second one to confirm your readings?

 

I suppose that it is possible that the tester is off, and I can get a rental to confirm. I think that my gauge is at least consistent, if not accurate, because I ran each test a minimum of two times and the readings were never off by more than 5 psi.

 

Gotcha. Others thought they had a rebuild ahead, only to find out it was the gauge, not the engine. It seems to be the cheap (ie. harbor freight) ones that have been an issue. Best to eliminate the easiest problems before assuming the worst.

 

Based on the dry compression numbers......just ride it.
You'll know when a rebuild is needed when you start seeing oil consumption (if you have any) increase, and a repeat compression check shows a significant decrease in one or more cylinders.

 

Finally some "doctors orders" that I can abide by!

 

Alright, I'm doing rear brakes and I'm stumped. What is this piece and where does it go?