Project Bike

Hi I am new to the Forums. I have an 82 xj750 I just got a couple of days ago. I have some problems.
The guy I got it from said it ran before he parked it a couple of years ago.
1. I only have 100psi for compression on all cylinders
2. I have no spark
3. When the battery is plugged in the neutral light on the gauges won't go off even when the key is in the off positions.
4. When I press the starter button, nothing happens.
5. Only some of the blinkers work, and the bulbs aren't blow; They also don't flicker, they just stay on.

 

Let's begin with the compression test. Bikes that have sat tend to blow low compression numbers at first, and the valves are more than likely out of adjustment, so don't worry just yet.

You obviously have some electrical issues. Take the seat off and look at the fusebox (it's mounted on top if the air box). What do you see? I suspect the PO did some "rewiring" While you're at it remove the headlight (there are two phillips (really JIS) screws on either side of the hedlight housing. The light tips out from the bottom. There are a lot of wiring connections in the headlight bucket for a PO to mess with. Of course it could be corrosion or mice that are the culprit, but every electrical connection needs to be looked at anyway (even if everything was working properly, because bad things happen when bikes sit).

I am going to jump ahead a bit and say that the ignition switch may need to be cleaned or replaced. There should be no power running through it with the key off, so if there are no obvious problems with the wiring we can have you test the ignition switch.

 

A soggy battery will spin the motor too slow to blow good numbers too.

From the whole situation, it sounds to me like an issue with the ignition switch is causing the battery to be continually discharging. The signals won't flash below about 2K RPM if the battery is low either.

 

K I checked the fuse box. I can only see 2 fuses in there and they are not blow. and behind the headlight everything looks good from what I can see.

 

Some PO f-ed with the fusebox then. There should be four fuses that protect four circuits.

The factory box looks like this:



Most of us replace it with this:



Some reading material for you:

Electrical System FAQ
http://web.archive.org/web/20071214043502/http://www.geocities.com/MotorCity/Speedway/7795/xjfaqbig.html

1982-83 XJ750 Seca WIRING DIAGRAM
http://members.tripod.com/dave_jack/wiringdiag/d11a.jpg
and
http://members.tripod.com/dave_jack/wiringdiag/d11b.jpg
Component Key
http://members.tripod.com/dave_jack/wiringdiag/d8.jpg


All that and more can be found in Chacal's Information Overload Hour (link in my sig line)

 

Wait, whoa. The "factory box" most certainly does NOT look like that; the factory box has all crimped connectors including on the fuse clips. Those are nicely soldered, modern stainless clips.

The factory box is however similar to the pic.

The pic The Dude posted is of a fuse box after being rebuilt with new clips from Radio Shack. (I know that because it's mine.)

I'm old school to a fault. You're better off retrofitting an ATC (blade-type) fuse box as in the second pic.

 

I did say "looks like" not "is exactly like"
That was the first picture I found that clearly showed the fuse labels and wire colors. I would have used a pic of my original, unrebuilt fusebox, but it's in the bottom of my spares box. Your pic is better.

 

I see you're in Utah. Altitude plays into the compression numbers. here are conversion factors for high altitude. For example where I am at I use .83 as the multiplied factor. What altitude are you at? You may need to convert the numbers in the manual for where you are.

 

What part of Utah do you live in? If your close to me I might be able to help (not that I'm an expert but sometimes another set of eyes helps).

Make sure the kill switch is in the run position. (I know obvious stuff but that's where I start when I have problems).

Do you have a manual? It is very helpful to diagnose problems.

Take a picture of the fuse box and post it here. if it does not look like one of the examples above you may need to change it out. (if you only have two fuses then you definitely will be).

I would not worry about the compression until you check your valve clearances.

Listen to what the XJ Wizards have to say they know what they are talking about. PM me if you want some help.

 

I am near layton if you are close then send me a message and we can talk. I will see if I can find any other fuse holders and I will get a picture up in the morning.

 

This is what I found. The PO just moved the 2 middle fuses. I also looked at the plug that runs to the starter button (that is under the tank) and it has some type of green slime all over the connectors. How could I clean them?

 

There is a cleaner that is meant for cleaning the connectors available at AutoZone and O'Reilys. Solvent cleaners tend to make the connectors brittle. Get some dielectric grease to put into the connectors once they are clean. This will help to prevent corrosion and poor connections.