690 Polaris Blvd. SE
Rio Rancho, New Mexico 87124
(505) 896-4699
(505) 410-8064 (mobile)
johnayleng@aol.com

Reed Valve Conversions for Kawasaki Triples.

My name is John Aylor and I started designing these kits in 1994. You may ask why, well the reason is that I can't leave anything alone! I always have to have more power. But as anyone knows that has a modified triple, the bottom end torque ends up on the floor with the port grindings. As I found out with my first 500 years ago. The bike was a rocket from 9,500 to 10,500, but below that rpm the Taco Bell dog accelerated faster (I think the bean burritos helped)! I ended up in diesel land (4 strokes) for the next few years (with a few triples sprinkled in). Then in 1994 I picked up a 1975 500. This bike became my "test mule". And after quite a few prototypes, and flow testing, the kits have shown to increase torque through the power band without reducing top end power. Also the 750 kit has shown a reduction in the surging tendencies. I have also seen and had reports of smoother running motors and increased fuel mileage. The reed conversion makes a modified bike much more enjoyable to ride, and the stock motor "torquier".

HOW REED VALVES WORK

 For those of you not familiar with the way reed valves work, here is a quick explanation. A reed valve is basically a one way valve made of steel, fiberglass or carbon fiber in the intake tract. On piston port 2 strokes (our beloved triples) the rear piston skirt is the intake "valve". A suction is created in the crankcase when the piston rises, when the back piston skirt uncovers the intake port the air/fuel mixture is sucked into the crankcase. As the piston falls, the intake port is then sealed by the piston skirt and the compressed mixture is then transferred to the combustion chamber through the transfer ports. The drawback to piston port motors is that some of the intake mixture is blown back into the intake port before the falling piston skirt can close the port. This causes what is called "double carbureting". There is now a double rich mixture waiting in the intake port and the lost charge is not being used efficiently. This causes jetting problems and not as much power that can actually be produced. The problem is much worse on modified motors. The rear piston skirt is shortened so the intake port is uncovered sooner to increase intake duration, but now the port also closes later and thus more charge is lost out of the crankcase. This causes a smaller power band and makes a “peaky" motor that looses a lot of it's low rpm torque. This is where reed valves come in. Holes or slots are cut into the rear piston skirt so the crankcase is always open to the intake track. As soon as there is enough vacuum in the crankcase, the reed valve opens to admit the air/fuel mixture. also as soon as the vacuum drops the reed valve closes the intake port trapping all the mixture in the crankcase to produce the most power. Now you can have more power without the major loss of low rpm torque. This is not a cure all, all out drag race motors will make more PEAK Hp, but they are not concerned with power spread. The rest of us can have a powerful motor that isn't a pain to ride on the street or road race track.

INSTALLATION INFORMATION

I have made the kits as easy to install into your cylinders as possible for someone that has experience with a dremmel or like grinding tool. The intake ports need to be opened up and holes or slots cut in the piston skirt. The instructions include templates and photos. If you don’t feel like you are up to the task, I can do the install into your cylinders. This includes modifying the pistons also (photo in the 750 Stage One section).

One of the big advantages with reed valves is that extra boost ports can be added off the top of the intake port. The triples are very limited in transfer area, and the extra ports helps greatly. I highly recommend this modification. Standard or super large boost port mods are available. The boost port modification can be seen with the 500 Stage Two photos.

"S" Series Stage One
 

Starting with the 250- 350 and 400 Stage One kit... This includes machining your manifolds to fit the reed blocks. If you would like to fit larger carbs, (up to 26mm) then I will need the manifolds from the larger motor. The carbs will be in the stock position with this kit.

 Price...............................................................................................................................$359.00

Stage One 500
 

This is the Stage One 500 kit.  This includes machining your manifolds to fit the reed blocks. The carbs will be in the stock position with this kit.  

Price...............................................................................................................................$359.00

Stage Two 250 350 400 500

This is the Stage Two kit for the 250 350 400 and 500’s. (On the 250’s, welding is required on the cylinders. I do not do welding) This kit is for use with large carbs from 30 to 34mm. The kit sets the carbs back 25mm (1”) and angles them up for a straight shot into the intake port, and carb clearance. Bolts included, but the rubber manifolds are not included.

Price...............................................................................................................................$399.00

Stage One 750
 

 This is the Stage One 750 Kit. This kit only moves the carbs back 1mm, so it had the “stock” look and the stock air box can be used with stock carbs. New heat barriers are included This kit will also take 34mmm carb.

Price...............................................................................................................................$379.00

Delivery usually takes 3 weeks. Please E mail or call for delivery time. Installation by appointment. Money orders in U.S. funds accepted (checks in the U.S. also) and Paypal. Western union funds will not be accepted.  There is an extra charge for Paypal fees and for overseas money transfers. Sorry no credit cards.   Make out all checks and money orders to John Aylor only. 

My Email address is johnayleng@aol.com

Or you can call at (505) 896-4699 if you have questions.

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