Xs gx400sp S.A.


XS400 New Member
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South Africa
Just wanted to share my find/project in South Africa.
It is a 1978 2A2 from what I have manged to find out about the bike.I am not sure where the GX400SP on the side cover comes from. Though it does appear in my internet searches but appeard to basically be a XS400.

When I purchased the bike I knew I was taking a chance in what the condition of motor etc would be.(The first pictures are an indication of this).

This would also be my first attempt at a modified motorcycle.My experience thus far has been keeping my bikes and cars serviced and normal wear and tear replacement items.

My original thought was to create a cafe racer but due to home pressures a two seater brat its what it may be.

After a few weeks of intermittently fiddling with the bike to see what is what the whole scenario has unfolded.

The bike has obviously been standing in the elements for some time and water has found it way through the carburetors into the motor.

Issues so far,carburetors are oxidized and gummed up not yet stripped so more issues are sure to develop.

Corrosion has truly stuck one of the tappet adjustment covers and will not come loose.
Any help/suggestions on how to get this undone will be appreciated.

There is some kind of rust/fungus in the right hand inlet port.

Motor will not turn to slow me to get to second bolt of the cam chain sprocket. The motor is stuck at TDC.

The kick start was turning without resistance.

The gear box has rust and oil and water.

Clutch plates are disintegrating.The basket appears ok.

So after trying without success to get the motor to turn,I removed a link in the chain so I could proceed with getting the head off.With the head of and after leaving the motor with penetrating oil for a few weeks still no luck with getting the motor to turn.

I then decided to attempt getting the pistons out by splitting the gear box casting.

So now I have everything apart and after cleaning th pistons are still stuck in the barrels and the gear box interernals
are looking a lot better and are turning though not totally free .

Some advice on how best to go forward from here would be appreciated.

I am worried about parts as my internet searches have not produced much here in SA.
Thanks Raymond 20200817_172058.jpg 20200817_172458.jpg 20200912_151106.jpg 20200825_180955.jpg 20200905_181329.jpg 20200823_135902.jpg 20200912_150144.jpg 20200912_150924.jpg 20200905_181316.jpg
Hey, Raymond. At your current status this information may be a little late, but could possibly help you or someone else in the future. Years ago, an old Harley guy showed me an adapter tool he made out of a spark plug (with the ceramic end cut off) and a grease gun fitting welded to it. He said the grease will build enormous pressure while lubing at the same time. The exhaust valves must be closed.

You stated that you soaked in penetrating oil. I've had success with PB Blaster, then rocking the bike back and forth until she starts to move. Adding heat to the equation makes a HUGE difference. You don't need a propane torch; a butane creme brulee will get the job done from a gas station in a pinch.

I've heard, but never tried, a last resort method consists of a small piece of wood and a sledge hammer. While soaking and hot, whack the hell out of one piston, measure, then do the same to the other side. You should research this prior to swinging away because I can't remember how far you can go before a stopper (sockets) should be placed underneath. In your case this should be irrelevant due to the crank being removed.

I hope this helps a little and wish you the best of luck.
I would be looking for a donor motor and maybe even a full bike for parts. It may make things easier and a lot cheaper than trying to rebuild that motor. New parts alone will cost more than most people would put into a xs400. That's if you can find them.
X2, that much water damage we junk all of it here. Not worth the effort and the new parts needed will be a new motor's worth anyway. You MUST bore bigger as enough rust to stick pistons means the cylinder walls will be oh so dead.
I'm afraid they are correct. If the engine is sentimental it could be saved. If you're looking for a challenge it can be done, however, it would save a lot of trouble if you were to spend a couple hundred on an engine(with compression). If it has compression you can get it running.
Good luck. Don't quit on her.