Reed inlet

[Bert44]

I’ve recently finished a complete rebuild of a 94 Wombat and it runs well. In the box of leftovers is a reed valve inlet. If I fit this to the bike without any change to carb or piston, will it have any effect? If I need to make modifications for it to work, what would they be.

[matt glascock]

Without changing carb or piston, you could fit that in between the carb and cylinder it you cut back the air boot. That would get you next to nothing in terms of a meaningful performance upgrade. To get the maximal benefit of converting to reed induction requires such modifications as a larger carburetor, substantial changes to the porting configuration of the cylinder, matching windows cut into the piston, perhaps changes in head volume/squish band, and a tuned expansion chamber. Then you need decent tuning skills and a jet/needle kit. You have a good running M94 Wombat? Perfect. Enjoy the heck out of it. Its a great bike as is.

[Bullfrog]

I'd offer these additional comments. 1) Simply bolting in the reed manifold without proper porting of the cylinder and piston would actually degrade engine performance because it introduces a significant impediment to the flow of fuel/air mix into the engine. 2) LOTS of trail bikes and trials bikes have been modified for reed induction in order to achieve much more precise throttle control at low engine speeds. In these applications it is perfectly normal to retain the stock carb and pipe - BUT, the cylinder and piston MUST be ported for reed induction AND the carb will NEED to be re-jetted. (NOTE: The porting allows the reed system to work as intended and sort of "makes up for" the flow obstruction of the reed system.
Ed

[taber hodaka]

Matt I know where you are coming from but a few things I have a different thought on. Modify the cylinder and the piston yes. I would be one to say you would not need a bigger carburetor, head or a tuned expansion chamber, unless you were going for maximum performance . ?? ------------- Clarence

[matt glascock]

Hey Clarence, on my piston port motors that have been ported for reed induction, I always am. Eeh, I take that back. I'm running the stock chamber on my reeded M95 CW but, to quote a reasonably decent tuner "it is a pretty good pipe".

[Bullfrog]

A lot of the misunderstandings regarding reed induction comes from the system's vastly improved carburetion precision as engine speed varies. This ALLOWS the use of whack-a-doodly large carbs and radical porting and "tuned" pipes to achieve utterly amazing high horsepower . . . and still have a "rideable" power-band. So there are TWO separate (but related) "issues" with reed induction. 1) the reed system always improves "bottom end grunt" which can be reason enough to use it for gnarly trails and for trials riding --- and 2) that improved bottom-end grunt means that race tuners can go ridiculously radical on porting and carb size while the reed "saves their bacon" by helping to NOT have a "light switch" power band.
Ed

[taber hodaka]

From the days of 66 all of us dealers and racers were trying to get the utmost performance out of our ace 90's. Radical porting gave you no low end performance, gas was moving both ways through the carburetor. With the reed added you got better low end than you had stock, along with high end performance. ------------ Clarence

[viclioce]

Speaking of porting, Clarence, I’m still waiting for that stock Ace cylinder you want to trade me for the highly ported one I have. Are you going to get it in the mail any time soon? Just curious… Victor

[taber hodaka]

This week I will have Jill do it as I am so -_S___ __-. the spped I am coing I can't slow down. I will try this week and send to a few oyhers. ------------- Clarence