Page 3
Don't try this at home! (Muzz Ed. LOL)
Another nice thing Suzuki 500 owners will like is the lack of sensitivity the engine exhibits over the long
haul. It isn't necessary to be continually tuning the engine. Set it and forget it. If the engine is put together
properly in the first place, once the carburetion and ignition are straightened away, the owner can pretty
much forget it just as he did with the stocker. Needless to say, this is a radical departure from the norm on
most hopped up motorcycles. The area we feel needs the most help is that of excessive weight. The
bike is very heavy, and if it would be possible to shed 50 or 75 pounds through the use of lighter compo-
nents, this would also vastly improve the overall performance factor of your reworked Titan.
Probably the one thing that took the most time and energy to sort out was the carburetion. Ron spent a full five
days doing nothing but coming up with the carburetion combination outlined in this article. Rather than make
it necessary to substitute the standard carburetor (which worked delightfully), it was decided to try to utilize
the stock items in an effort to keep the cost down. As it worked out, stock carbs proved to be just fine. The
changes were as follows. The main jet was raised to No. 260, and standard T5 needle jets and standard need-
les are retained. The pilot jet was changed to a No. 35, and a 2.5mm cutaway slide is used in place of the
2mm standard slide. Also, ignition timing was changed from 3.4, which is standard, to 3.1mm before top
dead center. This particular setup works best with the combination we are proposing in this article. Also, we
may mention here that it is imperative you retain the standard mufflers. Do not under any circumstances deviate
from the procedure and modifications we have illustrated in this article. To change the combination is sure to cost
you performance. Regardless of how much you think you know, restrain yourself and stick with the steps out-
lined here.
In the area of cylinder modification work, we would strongly recommend sending your standard barrels to Grant
and let him do his thing to them. He knows all the trick things and can guarantee the kind of performance you
are looking for. On the outside chance you prefer doing your own port work, included here are the specifications
needed for the necessary grinding work. The exhaust is raised 1 mm, and the port itself squared up slightly.
Also, Grant recommends leaving the intake completely alone except for cleaning it up and smoothing out the
path for the incoming charge. The transfer port, like the intake, should not be altered other than cleaning it
up and smoothing the port walls to removeany irregularities and surplus metal.
If your taste should run to a combination a little more competitive, we have some additional news that may
interest you. If you opt for the expansion chamber version that can only be used on the race track, here are
the necessary modifications you will need to know before becoming competitive. To begin with, raise the ex-
haust port 4mm. Like the street bike, remove the same amount from each side of the exhaust port. Here again,
don't touch the transfer port. From the top meeting surface of the cylinder to the top of the exhaust port the
dimension should be exactly 36mm.
The intake port likewise should be cleaned up, and you can lower the bottom edge 1 mm. Carburetion re-
quirements dictate something a bit more sophisticated, so we used a pair of TS250 hop-up kit carburetors
(32mm) that were equipped with No. 240 main jets, T5 needle jets and a No. 35 pilot jet. The cutaway on the
slide was 1.5mm, and we used a 6FJ6 needle in each carburetor. For adapting the spigot-type carburetor
mount to the cylinders, Suzuki makes a manifold to take care of this. The part number is 13200-30700. Like
the street bike, you will want to set the ignition timing at 3.1mm before top dead center. We mentioned be-
fore, you will probably want to use expansion chambers with this combination. The truth of the matter is it
will be necessary to use modified pipes over the stock mufflers. This particular combination only works
with the expansion chambers Grant sells for this purpose. Do not try to use the racing cylin-
ders with mufflers or use the street version port carburetion setup with expansion chambers. Make up your
mind which way you want to go, and then pursue that line of attack since each combination is different and
precise.
Go to step by step instructions and images
Next page
Classicbikes Australia
Muzza - 2002