Dare I even say......

[roboto65]

Oh heres the link LOL http://pelissier.joel.ifrance.com/380GT.html I would be pretty sure that the clymers has the specs in there somewhere have not seen one that did not

[TLRam1]

This is where I am at now.

Freshly bored cylinders, New old stock (see the old boxes) Suzuki Oversized piston & Rings. I chamfered the ports with an extension on my Dremel.

The rings came together and undisturbed, had to work a little to separate.

A few of the rings are too wide to fit in the groove. The rings stay stuck unable to compress in.  I thought it was the pistons at first but the rings that work do so in all of the pistons, the others do not. In the photos the bottom ring is okay, just the top ring.

I did check the ring clearance, it's at .009.













I will put on the Avons tomm.

[ezrydr]

As many miles as I put in on my old 380 and as many times as I had it apart (even split the case once), you'd think I'd know all this stuff, but it's just been too long and I don't remember any more.

I can tell you what I suspect happened to that center cylinder, though.  I bet the previous owner let it run out of oil, or had to replace a line or something, and got an air bubble in the oil injection system.  This will lock up the oil injection pump and then you get seizure.  Usually for some reason it's the center cylinder that goes first.  When you do put it all back together, make absolutely sure and bleed the oil injection system before you crank it up.  The manual you've got should show you how to do this.  It's very important - one air bubble of any size can cause big trouble.

Don't ask me how I know this....

Something at some time has seized that center piston, though, and you better try to find out what it was so it doesn't happen again.

As for being able to wiggle the piston head while it's in place, that's entirely normal if it's just the top of the piston that's moving - there's a really pronounced taper on those old Suzuki two-stroke pistons. 

One more thing to worry about:  the crankshaft seals.  If they're shot you'll get tremendous surging - you'll be sitting at a light or something and the idle will suddenly go crazy, sounding like the Devil's popcorn popper.  Doesn't seem to actually hurt anything but it's very embarrassing when it happens in town. 

If you really want to make that thing go, get hold of a set of carbs from a GT550 and a set of individual-stack K&Ns - you'll have to rejet a couple of sizes up or more, I don't remember how much.  You won't believe the acceleration.  Of course you won't have a decent idle and it'll make a Godawful honking sound when you crank it on, but you'll be able to humiliate a lot of bigger bikes. 

What really does it is an expansion-chamber 3-to-1 exhaust system, but I no longer know where you can get one - mine was made for me by an old guy in California who probably isn't even around any more.

It's a great bike, though.  Hope you have as much fun out of yours as I did with mine.

[TLRam1]

Oh heres the link LOL http://pelissier.joel.ifrance.com/380GT.html I would be pretty sure that the clymers has the specs in there somewhere have not seen one that did not

Great Allen, you care to translate?

Once I have the bike running as it should I may go back and do some porting on the cylinders and rejet the carbs. I missed a set of chambers some time back.

[roboto65]

Babelfish get it 

[TLRam1]

Update on the 380.

Bored .05 half over, bought new piston and rings. That's where the problem started. Rings did not fit, did I have wrong pistons or incorrect rings??

Piston and ring boxes as you can see with some age.



New .05 half over Piston and rings. The top ring doesn't fit, these use Keystone rings on the top.. Keystones are tapered on the top outer section going to a narrower taper towards the inside section but these would not fit. After buying a few sets I found ones that DO fit with proper clearances as you will see later in photos.



Checking clearance of rings inside of the newly bored cylinders, ,009 clearance. If the ring does not allow enough room you have to file the ring ends to allow for expansion.





Ready to go together, also as with the others I replaced the float needle valves. One float was leaking, I have another old bent float laying around so I unsoldiered    one and soldiered it on my good mount.

[TLRam1]

What I did this past weekend on the GT380.

It's together and it runs with no starter fluid. I will have to put on a few miles before I can see how it performs and do a compression test on the cylinders.

[hootmon]

Always liked that Ram Air look to the head fins..
Looks Great Terry, the bike is lucky to have you as an owner...