79 XS400 f Speical, 82 XS400 Heritage Special & 83 XS400K Maxim

[heritage]

Well what a day!

I am new to this group and I am still learning my away around my 1979 XS400 f. New bike to me = new problems = new opportunities!! LOL I have to say, I have been part of many different forum, but I have never been part of forum as informative as this website. Thank you to everyone.

The previous owner said the 1979 XS400 f bike was on the road 2-3 years ago and he indicated there were a few problems. We’ll he was right, today I managed to fix the clutch, gas tank mounting, change out the vacuum line and rebuild the carburetor, started the oil change – but I am still struggling with the petcock….

Oh lordy, never in my life when I went to drain the oil for oil change 2-3L of gas came out of the crankcase. I am just glad I decided to give the bike an oil change before trying to get the engine running ……….. There wasn’t even a drop of oil in crankcase.

With the said, I guess my next step is to repair the petcock or replace.

Note: I will probably be leaning on this forum for a little while because I have (2) boys – so there is actually (3) projects going on at the same time

· 1979 XS400 f special ……….. Plans to convert to a café bike

· 1982 XS400 heritage special (my high school bike) ……. Keeping it original

· 1983 XS400K Maxim ………. Plans to convert to a bobber

Does anyone have a 1979 YAMAHA XS400F PARTS MANUAL CATALOG? I found one online for $22 – I just thought I would ask the group before buying it.

I will also need a 1983 YAMAHA XS400F PARTS MANUAL CATALOG - eventually

Cheer

https://www.emanualonline.com/Motor...currency=CAD&gclid=CPKT0Oq5pdQCFQcGaQodeIgH3w

 

[heritage]

Here's the link for the xs400K parts catalog - anouther $22 if requried.

https://www.emanualonline.com/Motor...currency=CAD&gclid=CLzAm5DEpdQCFVZMDQodqsgN0A

 

[Jeff0133]

Welcome to the forum, will be following your progress.

 

[BBS360]

It's not all in one PDF but all the big parts websites have all the same information as in that pdf.
The Haynes manual (available on this forum for SOHC bikes) doesn't have the part numbers but does have the exploded diagrams.

 

[heritage]

Thanks BBS360
I have already downloaded the manual for SOHC bikes and it has already been very helpful. So far the most helpful information has been the part numbers with exploded view to assist in getting replacement parts.

 

[heritage]

We'll I guess this is where the fun really begins.
After draining all the oil / gas out of the 79 xs400 2f and giving it a proper oil change the bike now will not start? So I starting my digging and confirmed:
1) I am getting my gas
2) I am getting my spark
3) Not being 100% sure made sure no kick stand was sensor was being activated
4) I am in neutral

So I then continued looking deeper into the problem and started to think maybe the timing was out or the points.
After pulling the cover off, I discovered I had 2 broken wire and this is where I know I am over my head because I don't even know the name of the part. I understand the principle of how it works just not clear which wire connects where. I am lucky to have a 78 xs400 parts bike so I started opening it up to try to understand where the wires go. I think I now understand but
A) I don't know if I should repair the 79 (photo#1)
B) Who do you test the unit after reconnecting the wire
C) Should I use 78 parts (photo 2-3)
D) Recommendation on how to clean? I am assuming electrical contact cleaner and fine emmery?

Any advise on how to proceed an answers to any of my questions would be greatly appreciated.

 

[BBS360]

Looks like the '79 is missing the field coil entirely. There's nothing in the photo to reconnect the wires to. Do you have the field coil at all?

You could swap in the entire stator/field coil assembly from the '82. For that matter, you can leave the stator and field coil bolted inside the generator cover and swap the covers between bikes. The less you mess with the rubber grommets and wires the better. The wires get brittle and there are no replacements for the rubber grommets available.

If you want both bikes on the road eventually you'll need a field coil for both of them.

I didn't clue in before about the parts guide. Here's a link to the parts guide I made for my '82 SJ:
https://www.dropbox.com/s/v3byy75jhryv57r/XS400SJ Parts Guide.pdf?dl=0

 

[heritage]

Thanks for the feedback - I took the parts off the 78 as you can see in the picture. I do have a spare engine off a 83 maximum. Swapping the complete assembly is a good idea. I will keep you posted on how I make out with the new challenge. Thanks again.

Note: I guess I need to figure out how to use drop box. LOL

 

[BBS360]

I'm on my phone right now so it's different but there should be a download link somewhere on the page that comes up.

 

[16VGTIDave]

Put the Maxim on the other side of your work space. It is a totally different bike compared to your SOHC bikes. The only resemblance is the name. Most parts will not interchange.

 

[heritage]

16VGTIDave - Thanks but this one I knew ! There was a time I did not know LOL....

We'll I just installed the 78 field coil assembly and it fit likes a glove. I hear a little noise when I turn the engine over - I need to do a little more investigating.
The sad part is, I just made a rookie mistake - I told myself to label the wires but guess what, I got distracted so I walked away during the installation leaving me now guess which terminal does does the yellow & green wire go on. If memory serves me correctly - green goes on the terminal next to the sprocket. If anyone clarify - that would be great. Thanks

I plan on going after the points set up tomorrow and see where the grinding sound is coming from.