Suzuki 2 Strokes

How much can you over bore a gt380 cylinder? 2mm, maybe 3mm, 4mm(unlikely) ? Where is the liner the thinnest. Top near head... hmmm?

Well a Suz TS/TC/DS 125 piston looks like it would be a nice mild performance mod for a GT380.... std bore is 56mm versus 54mm, It is about 0.020" (1/2mm) taller, 2mm shorter skirt... these are estimates I'll have more exact measurement soon.

I would run an extra base gasket or two and thus only difference is 1.5 -1.0 mm intake I like how the cut outs are wider and a better match for the cylinder liner at transfers

A Yam DS6 piston looks like a nice mod for early GT250 with 16mm pin, Have to raise jug 1mm.

Anyone tried such foolish stuff

The Italians had a standard 380 that was 384cc and had a 55mm bore. So that will definitely fit!
Reference E34 region, cylinders 11210-33600/601 L, 11220-33600/601 C, 11230-33600/601 R for M/A models.
I have the piston types for standard and 0.5 or 1mm oversize if you need those.
So it seems like 56 mm bore will work.

Hi!

56mm bore is the absolute maximum.
Then a wall thickness of the liner of about 0.5mm remains.
Someone posted a picture of a GT380 cylinder with (too much) 57mm bore in a german GT-forum.
One can see a range with about 3.5mm height below OT, where the liner is completely drilled away.

Markus

markush wrote:one can see a range with about 3.5mm height below OT, where the liner is completely drilled away.

What do you mean by "OT" please

Thanks

OT is german for TDC

Hi!

Vintageman wrote:What do you mean by "OT" please

Sorry.
As "wolfgangh" wrote, OT = "oberer Totpunkt" = TDC

Here you can find the thread mentioned above. But you have to log in to see pictures.
http://www.mariolange.de/wbb2/thread.php?threadid=426

Markus

Rocco (Triplerocky) who was a regular here was based in Italy and had the Italian-market 384cc model, bored to 1mm oversize giving 400cc. It ran very nicely, he said

You shouldn't have any problems with head gaskets protruding into the cylinder even at 56mm bore.

The GT380 and GT550 liner at the very top is thin verus selsewhere (I have not measured) but look see

http://www.ebay.com/itm/Suzuki-GT550-GT ... 0E&vxp=mtr" onclick="window.open(this.href);return false;

http://www.ebay.com/itm/75-Suzuki-GT-38 ... 5F&vxp=mtr" onclick="window.open(this.href);return false;

I do think 2mm OS is OK 1mm off thickness, The person doing the job needs to center the jug well before proceeding to bore.


Why do stock piston transfer cuts out not match liner transfer slots. That is pistons are much smaller???? The TS125 matches well.

Having the piston transfer cut outs match the liner cut outs add any power???

Fun Stuff