New(to me) bike, number of questions

Hi, Just purchased an 82 Xj750RJ and had some questions.
The bike was reportedly ridden some, stored indoors, someone had sprayed it flat black... sanding down the bike suggest the original owner didnt since the tank was sun faded...

Probly payed tooo much but oh well ;p

Lots of questions
Electrical:
1.) Suggestions on electrical connection cleaner ? the connections on many of the terminals have that little bit of green oxidation..

2.) manual says the voltage should run 14+, but i dont see that til 2k+ rpm.. (it doesnt specify off idle or not)..

3.) flashers only work at high rpm (high voltage), Cleaned the connections etc, the back ones are not 1156 (27W), but rather some little 23w ones. Are the flasher pods that picky ? ;p

brakes:
1.) I notices a crack from one of the slots to the outter egdge, after more inspection it seems a number of them are forming the same stress crack there.. What replacement options are there ? (havent tried to use the "Xref".. )

It doesnt pulse much at all, should i not be so 8O ?

Engine:
1.) the airfilter is covered in oil, I check the plugs and they are not fouled after probly 100 miles since i picked it up.. (if anything a little too white). Normal ? thoughts on using a crankcase filter ?

2.) Did use bikes come with MPH speedo's ? (they last owner bought an ebay replacement and it's metric LOL )

Overall:

Trying to get a few tanks of gas thru it before i tune it much.. runs ok, but have to keep the idle high (1500+) or it starts hunting.

Any "normal problems" to hunt out would be appreciated..



Knick

 

Not much I can comment on here...

On other bikes I've worked on, the turn signal flasher units are very picky and will only work well with the right resistance/wattage. The first thing to try would be putting in the recommended bulbs.

 

A few comments:

The brake ROTOR is cracked? Or the pad? If the rotor has anything but minor wear gooves, you wouldn't catch me putting any miles on it. Maybe I misunderstand.

Oil in the air filter? What's your oil level like? Sound liek it might be overfilled. OR you might have gas in your oil from a bad petcock and ineffective floats. I'd make sure your oil was clean and at the proper level before you ride it too much more.

US bikes? Yeah, it should have an "English" speedo, not Metric. I suppose you could write the important MPH speeds in with a Sharpie. Heck, while you're at it, why not clock in knots?

As for the electrical, I've found that when my idle is off, power output seems weak as well. I'm still no certain which is the cause and which is the effect. In fact, once my idling when downhill, my blinkers would flash really slowly or not at all. A flick of the throttle and they'd be back to normal. One thing you might check is your spark plug gap. If they're too far out, perhaps you're overworking the coils. I'm just grabbing at straws there, though.

Good luck. Welcome to the family.

BTW, I believe there's going to be a carb clinic in your neck o' the woods soon. Be sure to look for details in the other forums.

 

Welcome to the forum, looks like you brought some problems with you (kidding). Let's start at the top:
Electrical- our toys are notorious corrosion pigs. The green crud is corrosion on the exposed copper of the connecter (kinda like a penny). There are few ways to remove it, abrasion, bead blasting, chemical acid dip, none of which is easy or quick. I personally use a small Pasche Air Eraser (mini sand blaster), messy. Acid is another messy route. Refer to Dan's Motorcycle Repair page (http://www.dansmc.com/soldering.htm) and he'll guide you through it. Abrasion, how do you clean inside the connector this way? It ain't happening and if you don't get all of it out, it's coming back shortly. Bottom line, Replacement is the ONLY way to get it removed permanantly.
Your undervoltage until 2K RPM is normal according to the Haynes manual. Your voltage measurement is correct. No problems there.
Get your bulbs replaced with the correct wattage. The system load may not be enough to trigger the relay, especially at low speed.
Brakes - you got me there. I'm no brake specialist but cracks are not good. I would examine replacement if I were you, sorry.
Airfilter - bad juju that oil. Either the valve stem seals are toast or your rings are worn and a butload of crankcase pressure is pumping oil into the airbox. Either way, you've got to do a compression test to begin the troubleshooting process. Could also be the previous owner was a little distracted and oiled the airfilter (a no-no on the cotton gauze types). Hard to say, do the compression test.
Speedo - your in luck! Bunches of the English standard were made and can be had for a reasonable price. Hit flea-bay and wait, they will come.
Hunting Idle - your bike is telling you it has a vaccum leak. Get out the WD40 can and start spraying the joints of the carburetor. I'm guessing your intakes are cracked or the gaskets went on vacation.
That should hold you for a while Knick. I hope you get the little stuff ironed out quickly. That compression test cannot be understated, get it done as soon as you can. Welcome once again and I'll see you soon.

 

What is the proper use of WD40 in this case? Will you see it getting sucked into the crack? I don't imagine it'll bubble. Clarify, please?

 

When the vaccum of the engine sucks the liquid (it doesn't have to be WD, could be carb cleaner), the leak is momentarily sealed and the rpms should smooth out. It will be noticable.

 

As mentioned already - your description of the front brake sounds like the slots in the rotor have cracked out. Replace immediately. Failure of the rotor can lead to dramatic and unexpected results. If you are not sure, and for our own records here, please take a picture of the area.

As for the oil filter. Start by checking the oil level. If the oil level is high you've found the problem. If the oil looks funny at all just replace it. Infact when buying a used bike with unknown history it should be the first thing you do... it's cheap and it's peace of mind.

If you find the oil level high then you have to track down the cause. Two scenarios - the previous owner over filled with oil, or gas is leaking past the carbs ( floats and petcock in need of service) and into the oil bath.

If the oil level is fine and the oil on the filter is definately motor oil then you'll need to hunt more deeply. Robert has described this well and can describe it in more detail if need be.

electrical - no biggie. Sounds like improper voltage bulbs. If not it's simply a connection problem. Use hand signals if you're worried. Fix as soon as possible but the other problems are far far more important to resolve.

 

Thanks all.

On the rotors I am looking at replacement but oldbikebarn etc all show either backordered and/or 225USD + for each rotor

The bikebonyard.com is the only big bike salvage place i know off.. Looks like he just got a 750 in, but wanted to see if there were any aftermarket ones (cheaper than oem), and make sure that there wasnt a generic design flaw with those huge arse slots stressing out.

guess i need to was "flea' bay" ;p like than name..


On oil: level looks about right 80-90% up the window when the bike is on the centerstand.

On the seafoam I assume you mean a gas additive application vs oil ?

Kind of leary of putting anything in the oil due to the clutch

I thought about a light dose of Lucas stabilizer... (thought it might help with the final drive also ?) hmm seperate thread ? ;p

Oh.. On price.. $1100... I have been looking a while and around Austin anything than runs seems to go for 1k+. Part of that might be a number of guys scooping up the diamonds in the rough and a quick paint/polish and resell..

So anyone looking for one of those bikes that sat in the garage a year or two and the owner wants to clear out seems SOL here

Thanks again.

 

Guys: don't forget the obvious! When my brother bought his XJ650 - it came with an air filter that is supposed to be oiled.

Is your air filter paper folded up like an accordian, or foam? If it is foam, it is supposed to be oiled!

If it is paper, are you sure it is not gas? That would be more common to have a gas soaked filter. That would mean a problem with the petcock and carbs.

 

Also - if you talk to any oil engineer - they will tell you not to add anything to the oil. The oil company spends a lot of time getting their additives right. If you add something else, it screws with the very tightly controlled mixture.

Why not just buy a high quality oil in the first place? I think it is worth it for gas mileage, life of the engine, piece of mind, extra horsepower, and if you go synthetic, you don't have to change as often! That means more riding time.

 

FWIW, the only time I've heard of adding Sea Foam to the oil is right before a change to help clean the gunk out. So yeah, I don't think anyone was suggesting oil additives.

And as for oil versus gas on the air filter, or even filter oil (ie K&N), I mentioned that in one draft of my initial response, but it seems I foolishly cut it out. Good points.