Suzuki 2 Strokes

Hello, I have a porting question. I have a gt750b and since I already have the engine apart, I'm wanting to do a mild port job. Since I have a mab barrels is all that is required is too clean up the rough edges? (I'm wanting a streetable combo- jemco pipes, 36mm mikini carbs) my other question is on my intake ports the split goes pretty much all the way back where is alot of the pictures I have seen of ported gt750's the split only goes halfway through, is that a necessary modification?

The question is how much HP are you looking for?

MAB inlet port floor is too low for a mild touring street bike, and that's one reason why a Lift/spacer plate works so well for the street.

But that still leaves stock short blowdown and that restricts power and revs, so the exhaust port has to be raised even further and if you are not careful , that may go too far so think through the numbers.

Without a lift plate and mild porting, you can make over 75hp at the rear wheel with stock carbs.

The intake divider is long and can be shortened, or completely removed (apart from a small bump) but that is a load of work without a lot of gain.

Im looking for around 75hp, so I wont need new carbs then, by mild porting do you mean judt cleaning up all the rough casting edges or slightly enlarging the ports? I have seen some porting diagrams and it shows taking off 5mm on the exhaust port which seems like an awful lot for a street bike

To get a real gain you'd need to enlarge the port windows as well as cleaning them up for flow. TZ and others know way more about this than I do, but for a street machine, a 5mm higher exhaust sounds way too peaky to me, and you'd lose compression too so you'd need to skim the head to compensate.

5mm is rather a lot on an MAB barrel, but would be fine for a JKL barrel. Ports need to be cleaned up and widened. Exhaust port needs to be raised with a spacer plate or by porting.

Transfers can be widened if you have the appropriate right angle porting tools and left hand carbide cutters.

Inlet roof can be raised enough so that it open at TDC but not so that it uncovers the rings if possible at BDC - It's a balancing trick.

Compression needs to be raised a little. 1mm off is usually enough but that depends on your comfort level with a high compression 2 stroke. Ignition should be changed to electronic and fit fine wire plugs. JEMCO chambers will work at that target HP level.