Almost finished XJ900 rebuild, but have some questions.

Hi there,

I've been rebuilding an XJ900-31A 1983 for a little over four years now. Almost everything is done, you name it, I've probably done it (carb rebuild, complete engine overhaul, forks rebuild, tank coating ...)

Now I have a few questions left.

Question 1: Just to be completely sure what carb tube is what. Am I right about these things?



- 1 is the fuel line and should be connected to 1 in the picture of the fuel petcock
- 2 are vent tubes and remain unattached
- 3 are overflow tubes and also remain unattached



- 2 is the vacuum line and connects to 2 in the picture of the fuel petcock





Question 2:

I don't have the part indicated 3 in the picture of the fuel petcock (the in-tank filter standpipe), and I don't know where to get it. Any ideas on how to solve it, can I just put the petcock on without using it, do I use some tube, do I use a fuel filter that you normally put outside the tank?

My last problem is that the bike doesn't start up when I use the start button, but it does when I short circuit the starter solenoid. I've found some information on this forum (http://xjbikes.com/Forums/viewtopic/t=1 ... =next.html) , and I'll try it out.

A quick before ...



...and after picture of my XJ. I'm not completely finished yet, but I'm getting there.



Any help is really appreciated

 

Looks good! You're right about the pipe connections, and if you can't find the in-tank filter then an in-line will do the job just as well.

 

if you dont have the "in tank " filter, then you would loose the reserve facillity,
as the filter has two separate tubes one shorter than the other , so the fuel would drain down to the bottom of the tank when in use, loosing the reserve
capacity.
stu

 

nice progress so far, throw up some more pics!

 

You can get a new standpipe from our resident part expert Chacal at XJ4ever. Just click the banner at the top of every page to be taken to his section. You will also find a lot of very usefull information in that section. Or just PM him with your bike info, and what you are looking for.

An inline filter is deffinately recommended also.

I may be wrong, but hose #2 on the carbs may be a vent hose to the airbox. The vacuum petcock is normally operated from a hose off the #3 intake boot/joint.

Your no start button is most likely no ground on the painted/coated handle bar. The button grounds through the switch housing to the handle bars.

Ghost

 

This black headlight could be pretty much the size I'd like to put on my Magna, what is it and where did you get it?

 

Those Manifolds are on the Carbs "Backwards"
The 1-2 and 3-4 need to be swapped.
The Hose needs to be replaced.
The Hose runs from Manifold to Petc0ck Vacuum nipple.

ALL 4 Vacuum Nipples belong pointed UP.
It does not matter which Vacuum Port you use to hook-up to the Petcock.
Stock is #-3.

All the Vent Hoses are bundled and terminate in the space below the Airbox.
The only Hose connected TO the Airbox is the Crankcase Vent Hose which runs from the hose fitting at the rear of the left-hand side Shift Cover with an "S-shaped" Hose which connects to a fitting at the bottom of the Airbox.

(Swap the Manifolds. ALL 4 Vacuum Nipples UP.
They should look like this:

( /1 /2 ~ 3\*4\ )
All Vacuum Ports at 12 O'clock
They slant to match the Head.
* = Vacuum to Petcock

 

Thanks for your help everybody.

Since the vacuum pipe going from the nipple to the petcock only deals with air, any fitting hose will do, right?

The picture (3) with the manifolds on, is a before picture, they're on the right way now, but thank you for pointing it out. (I actually just went to check if they were the right way round.)

The hose to the air-box indeed starts from the shift cover on the left, but I've eliminated the air-box and put pods on. (I know to some of you on this forum it's a big NO )

If I get it right, I could just as well put no in-tank standpipe or filter or tube on the petcock but as a result I will only end up with having no reserve. I've coated the inside of the tank again and it seems rust and dirt - free to me now. But in that case I will certainly use an inline filter though, I'm OK with cleaning the filter in the petcock from time to time, but I'd rather not clean out the carbs too often, since that is quite a job. I can live with having no reserve, it really is just a matter of finding out once how far you can go with a full tank, and then building in a safety zone when you actually go out riding.
Or I could us two tubes in the tank, a shorter and a longer one and put inline filters on both of them, or will that be a case of overkill. (Maybe I should just order the part from Chacal, but since it has to be shipped from the States it could get rather expensive and if the customs-officers here are difficult, which they are most of the time, it could take a very long time)

About the start-button, it did actually work a couple of times, but after a while it stopped (It could've been after putting on a different brake master cylinder in the front). I'll check out the no ground issue this afternoon, thanks. (The light-switch in the same part works though). On the other end of the bars, the horn doesn't work either, so that could be a ground issue as well?). But since I don't have indicators on the bike anyway, I might take off the whole left hand switches and replace it with something simpler. (I've also gotten rid of the 'auto'choke).

I got the headlight on ebay, I didn't get it from this vender (I got it a bit cheaper from Germany) but it's definitely this one. (http://www.ebay.com/itm/Cafe-Racer-Stre ... c9&vxp=mtr).

I'll put up some more pictures when I've got the bike running. This is my first project by the way, might explain why I'm working on it really slow and asking stupid questions from time to time.

 

they're not stupid questions at all, you needed confirmation on a pipe issue which you got answers to, and you were also able to post pictures of your question. dont forget we all read the posts even if we cant give answers,
so were all gaining knowlege at the same time.
cheers
stu

 

Nope!
Not "Any fitting hose".
Use certified VACUUM Hose.

Non-vacuum hose heats-up and collapses together, ... relaxing the vacuum at the Petc0ck.
The Bike stalls.

Run lengthy sections of Gas Line and Vacuum Hose so you dont have to unhook for tweaking Carbs.

 

great post mic-hell. it actually helped me out alot too. wanted to add one thing, and someone correct me if im wrong. make sure the in-line filter is vertical or can cause a bubble?

 

Those Big Mikuni's might handle those Pods fairly well, ... but I hope you didn't wreck the Airbox.

An "Intermittant" START Button might be a problem other than the Button.
Inspect the Commutator of the Starter and the Length of the Starter Brushes.

Excessive Carbon Dust on the Commutator and the surrounding Brush Plate inside the Electrical-end Housing can interfere with the Starter functioning.

You can pull the Starter quite easily.
After undoing the two long fasteners on the starter; the Housing can be pulled away enough to view the Commutator and Brushes.

If the Brushes are OK, but the Housing and Commutator fouled with Carbon Dust ... douche the whole deal with Isopropyl Alcohol.

You can buy two Plastic Bottles at the Pharmacy.
Pierce the Seal with a sharp pencil point.
Squeeze the Bottle.
Squirt the whole of the Electrical-end until what drips-out is as clean as what you squirt-in.

 

Well, I've used Gamuru's How to test your starter circuit, and completed steps 1-4 and 6 without any problems. Step 5, 7 and 8 could not be completed, so the problem is with one of the safety switches (clutch, sidestand or neutral).
Just to make sure it wasn't the starter button, I bypassed the switches by hooking up the solenoid's red-white to the battery's +, and after I pressed the start button, it fired up fine.
Next step is to find out which of those switches refuses to work, my guess is the sidestand switch. I've had problems with that one on my Bonneville as well; dirt keeping the (in this case) button pressed in, and thus fooling the bike that the sidestand is still out.
RickCoMatic, I've seen your post about the Gremlins that bite these bikes in the topic mentioned earlier, and I'll definitely look into that as well.
In the worst case scenario I can still bypass these 'safety' features permanently.
And again, thanks for the help and the good tips you guys keep giving me. I'll let you know if I find out what the problem was.

 

Be sure its not mechanical.
The Rod activating the Sidestand Switch often Binds, (sticks) leaving the Switch closed.

 

I have just done as you said with mine and I fuel coming out if the vent holes and bike won't start

 

Please address this in your existing thread.

84 xj900f