Allow me to introduce myself...

Hello from Denver! When talking to a gentleman in my office building about my electric motorcycle, he mentioned that his friend was getting rid of an old UJM. A phone call and a two hour drive later I was the proud owner of a very rough 1981 Seca XJ750R that had been sitting since August of 2015.

In my mind's eye I had been planning a cafe, but a craigslist search brought me a tour pack (front and lower fairing, saddlebags, trunk). Underneath the dirt and grime and truly distressed paint I think the bike might actually be in pretty good shape.

The tires are shot, but the air and gas filters are recent. The seat is ripped and the tank is dented but rust free. The front brake squeezes nothing, but the clutch disengages and it shifts freely.

I removed and cleaned the tank, and my new battery just arrived. Anything I should do before gassing it up and seeing if it starts?

 

change the engine oil

 

check the oil level through the sight glass on center stand to make sure your oil is not full of gas. proper type oil Jaso ma approved oil change and oil filter
2 years is not a long time.
check and grease wheel bearings
rear brake shoes need to be checked for delamination
lube up all the cables ,clutch, tach, speedo and gas.
check wet fuel levels on the carbs before you remove them if you can not get a proper level reading it whil mean you have a internal leak in the carbs

I would also suggest a carb cleaning
proper type oil Jaso ma approved oil change and oil filter

you will need to rebuild caliper and master cylinder also replace brake hoses




then read information overload
some reading for you

The Information Overload Hour

The Ultimate Relay, Switch, Sensor, and Diodes Guide

IN THE CHURCH OF CLEAN

THE SECRET LIFE OF CARBURETORS

Something New, Something Naked

TALKIN' TECH: Various thoughts on various issues


AIRHEAD VALVE ADJUSTMENT with Pics

AIRHEAD VALVE ADJUSTMENT Part 2: The Tool vs. ZipTie -w/pics

Choosing Oil for a Wet Clutch Motorcycle


SAFETY ALERT Drum rear brake bike owners please take a look


our forum supporting vendor plenty of parts and advice Chacal

XJ4Ever - Supporting Vendor

his web site
www.xj4ever.com

 

ohm out the charging system
ohm out the ignition coils ,plug caps and pick up coils . specs are in ultimate relay link above for both systems
clean and lube ignition switch
see how at this link as well as other things you may want to do

http://www.xj4ever.com/downloads.html

 

Any forum recommendations on oil and filter brands?

 

oil needs to be motor cycle oil some use yamalube
I use shell Rotella triple oil it is jaso ma rated http://www.kmart.com/shell-rotella-...d=KDx20141028xBingPLA&kisgs=082W085129611612P
any oil filter is good they all do the job

Choosing Oil for a Wet Clutch Motorcycle


JASO , MA, MA2; is the important thing to see on the label

 

Here is where we start...

 

she is a nice looking ride

 

I fore see great things in your future!

 

Allow me to introduce myself...
I'm a man of wealth and taste

excellent tune, now stuck in my head

 

Yep - my head went there right away also . . . .

 

Woo Woo!

This x3.

 

At least the devil said Please.

 

I rode a tank, held a general's rank
When the blitzkrieg raged, and the bodies blazed.

 

Okay, I'm stymied. The battery had been installed backwards (positive to negative). I pulled it out and installed the new battery correctly. I found a 20amp fuse that had been blown under the seat and replaced it - all the other fuses are good. I have reconnected all the connectors in the headlight area which I had disconnected when I traded out the old bucket for the tour pack fairing. All the wires match up connector and color-wise.

The wire to the clutch switch had pulled out, so I stripped them and wrapped them together.

Currently (oof) I have no power to the headlight. The atari warning words switch on and stay solidly on. The turn and brake signals work. But there is nothing happening when I press the starter.

Where should I begin? And what damage might have been done with the battery in backwards?

 

Check for continuity at the starter button when you press it. You likely just missed a connector, or have one that isn't fully seated, or have a corrosion/wear issue at the switch that has popped up.
While it's possible to do a lot of damage when reversing the polarity of a battery, it seems like you probably just made the main fuse blow.
The headlight won't have power to it until the engine starts. The Atari won't come off of default mode (all things lit) until the engine starts.

Other things to check;
Side stand switch. Unplug the sidestand switch relay (blue dot on the relay, located under the tank behind th turn signal relay). This will bypass the sidestand switch and allow th bike to start if the sidestand switch is at fault (they crud up and get sticky. easy to clean).

The starter solenoid: jump the two large terminals with a screwdriver to make sure that the starter still works. Run jumpers from the battery to the solenoid plug (small wires) to check the condition of the solenoid itself.


Also it's a good idea to put the year and model of your XJ in your signature so it's always available for refrence.

 

Thanks!

 

+1 on the K-moe above, making sure you jump the starter solenoid will point you in the right directing. I might have missed it, and not sure this bike has one but is there a clutch safety switch as well? If it does either pull clutch in or bypass that switch as well. Good luck and keep us posted.

 

He bypassed it.

 

K-moe wins the prize! The bracket that used to hold the sidestand switch is empty, so I imagine the PO bypassed it. But I couldn't locate the bypass. Pulling the blue-marked relay did the trick and now the starter turns. The bike doesn't fire, but at least its something.

No spark. Time to test the coils.

 

I had looked for spark by pulling a plug and grounding it to the engine while I cranked, but saw nothing.

I'm reading 3.3-3.4 Ohms on the primary side of both coils, but no reading at all on the secondary side of either. I set my multimeter to 20k Ohms and went from the pigtail to the inside of the plug cap (trying both sides of the pigtails with all 4 plug caps). Am I testing this correctly, or are both my coils bad?

 

You test the secondary windings by removing the plug caps and sticking a probe into each spark plug wire pair. The plug caps should be tested seperately, and the origianl plug caps have a screwdriver slot for removing the ceramic resistor if the resistor has failed.
The plug wires my have corrosion; just trim the wire back 1/8" or so to get to clean wire.

 

Two of the plug caps (to the outside cylinders) have the screw/resistor/ spring. Took them apart. No obvious signs of corrosion, but I cleaned them and shortened them anyway. No reading at all from the pigtails to the screws, so I took the cap off and jammed the meter in the end of the wire. Still no reading.

The other plug caps (to the inner cylinders) are shorter and have no screw or other obvious way of removing the inside section. I shortened them. No readings from this side either.

Next step?

 

Just for giggles I checked the plug caps by themselves. The short ones give me a reading but the long ones do not.
Reassembled everything, still no reading through the coils.

 

Just want to get this right, you took the plug caps apart? You shortened the spring inside the spark plug caps or the wire running from the coil to the spark plug cap?
Just want to be clear here...thanks

 

Also to be clear, you are putting one probe into one of the plug wires, and the other probe into the other plug wire from that coil (this is the correct testing method).

 

No problem - its hard sometimes to keep things clear. I'm grateful when anyone even tries to understand others on the internet these days.

To clarify: I removed the coils from the bike. I took the plug caps off the wires from the coils. I shortened each of the wires by 1/4 inch, then reattached the plug caps. On the two longer plug caps I pulled the screw/spring/resistors out and cleaned each piece and reassembled them. The two shorter plug caps don't seem to have any way to disassemble them. I don't know why they are different, as the coils and plug wires look identical.

For kicks, I also tried a different multimeter. It read slightly lower on the primary side of each, but again no ohm reading from the coil to the plug caps.

 

On testing: I placed one probe in the pigtail from the coil, and the other probe in the cap. I also tried placing the probe in the bare wire after I had removed the cap. I tried each version of the above with both leads of the pigtail and with the contact point where it is soldered to the coil.

 

Okay, I think I understand. I retested from plug cap to plug cap. On the short cap side (the outer cylinders) I now read 26 at 20k. On the long cap side, I read 11, but only after I strip the caps and insert the probes into the bare wires.

 

The coils test good.
The coil secondary itself should read 11K ohm +/- 20%
The 1/4 plug caps (outer pair) are 5k Ohm
The 2/3 plug caps (inner pair) are 10k Ohm.
I think your inner caps are either shot, or of the wrong type, or both.

 

test the pick up coils too

chacal sells after market nkg replacments caps

 

It's Alive!

A broken choke cable was the immediate culprit. Operating the choke by hand lets it fire right up. New cable is on the way.

Next step, tires and brakes.

 

And a sidestand switch so you don't have an unexpected problem turning left.

 

K-moe, I just realized I've been reading your comments on the BMW Alpha build. The internet works in mysterious ways...

 

Is there a method for removing the inside panel of the atari cluster? Mine is significantly rusted and I'd like to paint it. I got the front cover off, but I am stymied at how to get to the metal bezel.

 

It's held in by a plasic trim ring that's fusion welded to the outer cover. Tread carefully.
Keep in mind that the housing lens is untempered plate glass, so be careful for the sake of your fingers.

http://xjbikes.com/forums/threads/atari-disassemble.47704/

Gauge Cluster Breakdown

 

Thanks for the info, k-moe. That second link for the breakdown appears to be broken, btw.

After the choke cable failure I have replaced the entire set of cables (choke, throttle, brake, speedo, clutch). The brake system is getting an overhaul - pads, shoes and Galfer ss lines are on order, although I still haven't figured out how to get to the master cylinder to remove it. I love the line from the Haynes manual (thanks again, xj550h!): "The remotely-mounted master cylinders of the above models are well hidden amongst the various ancillary parts attached to the steering head, making access rather difficult."

 

You have to remove the headlight and headlight bucket.

 

Lol, neither exist on my bike. I traded the bucket to the gentleman with the touring rig.

 

So you can see the master cylinder pretty easily then. It's bolted to the headlight mounting bracket. The bracket bolts to the lower triple clamp just below where the fog light mounts, and is held at the top by the instrument cluster studs (the nuts are on the underside of the upper triple clamp).

 

Thank you, K-moe. I was able to remove the whole assembly. It's in pieces now, along with the calipers, awaiting the master cylinder rebuild kit plus new lines and pads.

Managed to get the tank stripped. Looks cool this way, but I need to think about paint. I was able to score a pair of side panels off eBay (what's up with the scarcity of right side panels?). I rattle canned them black to match the tail/fender of the Seca, but I don't think that will look good with the burgundy fairing.

 

right side is the one you take off all the time , leave on floor while you remove battery then step on it

 

I knew there must be a reason!

 

Is there any general maintenance I should do on the shaft/final drive while I have the rear wheel off? I'm going to drain and replace the oil, throw on new wheel bearings, and I installed new brake shoes - anything else recommended?

 

That looked ugly, but much cleaner now.

 

Anyone have a diagram/pictures/faint idea of how the touring fairing support and saddlebag supports go together? I'm about to start futzing around and thought I'd ask first .

 

Any idea where this bracket goes?

 

That doesn't look familiar, but then I have the sport fairing bracket.
It's definitely not for the luggage rack.

 

I'm sorry but every time I read this thread title I think of

 

Searching online I found an image from an expired european eBay add that called it a "rear bracket mount". Still not sure what it does. I'm planning on mounting the rear rack and panniers, but not the top box. Maybe I don't need it...