Reed Valves

yeah that is some good information, once i get a better more permanent, better equipped shop situation i will attempt all this but it is still new to me, for now im gonna stay away from the reeds as my current setip is already very tight for space and i want to see what one of these motors will do with pretty much every mod but that for now, such as maximum compression, pefectly dialed name brand carb, top notch balanced crank and super high rpm bearings throughout, port work, modified igniton maybe even custom expansion and header
 
Fuji Moto said:
yeah that is some good information, once i get a better more permanent, better equipped shop situation i will attempt all this but it is still new to me, for now im gonna stay away from the reeds as my current setip is already very tight for space and i want to see what one of these motors will do with pretty much every mod but that for now, such as maximum compression, pefectly dialed name brand carb, top notch balanced crank and super high rpm bearings throughout, port work, modified igniton maybe even custom expansion and header
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If you're going to do all that work?, I would highly recommend that you do the extra work & use a reed! (You'll be happy that you did). ;)
 
I agree with Venice. The RSE reeds fit the carb closer 2 the jug than stock & the Arrow reeds allow an offset carb so space wont b an issue. Hey Venice, when u boost ported the jug, wot width did u make it & how deep did u cut it. Cheers
 
I have a RSE reed valve on a new build. Although engine isn't broken in yet, it is very weak and has almost no torque. I'm going to switch the reed valve to a current engine that has a couple of thousand miles of use on it to see if it helps this engine.
 
I posted pics of a cyclinder that I ported... http://motorbicycling.com/showthread.php?t=40285

If you install a reed valve, you must modify the piston & cyclinder, or you might see poor performance.

I've never tested a RSE reed, but from what I've seen & read about them, they are much smaller & the top half of the reeds are held closed by the top wall of the cyclinder intake port. (So it sounds like they flow a lot less). Maybe raising the roof of the intake port will help this??
 
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Hi Drewd, did u (1) remove enough metal from the cooling fin above the intake port & (2) correctly rejet leaner. If u dont remove enough of that cooling fin the reed cage will not b able 2 seal properly 2 the jug. I remove aprx 1/2"x1/2" & 1/4" radiused it all. I had 2 downjet from 77.5 to 72.5 main jet & 27.5 to 25 pilot jet (16mm mikuni) for correct tuning & noticed a gain in low & mid torque. Next step will b removal of 5mm from piston skirt & intake port floor, piston port & boost (also called 5th porting as most motors have main & secondry transfers) porting the jug, which will require a considerable upjet. Cheers
 
Hi Venice, I got RSE 2 machine up a manifold 2 fit 16mm mikuni 2 the reed cage. The stock manifold is bored thru at 14.5mm for NT carb. The mikuni manifold is bored at 16mm. Both r smaller than the reed block intake. The double duckbill arangement only protrudes a few mm into the port, I cant the upper reed petal fouling the port ceiling, but new base & head gaskets & piston pin circlips turned up today so sometime over the next week I'll do the other mods & I'll measure the clearrance & post. Cheers
 
ivan H said:
Hi Drewd, did u (1) remove enough metal from the cooling fin above the intake port & (2) correctly rejet leaner. If u dont remove enough of that cooling fin the reed cage will not b able 2 seal properly 2 the jug. I remove aprx 1/2"x1/2" & 1/4" radiused it all. I had 2 downjet from 77.5 to 72.5 main jet & 27.5 to 25 pilot jet (16mm mikuni) for correct tuning & noticed a gain in low & mid torque. Next step will b removal of 5mm from piston skirt & intake port floor, piston port & boost (also called 5th porting as most motors have main & secondry transfers) porting the jug, which will require a considerable upjet. Cheers
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Yes, I filed cooling fin for proper fit. Piston skirt has been trimmed. I wonder if I got a bum engine. I'm putting it back stock, stock piston, stock slant head, stock intake, stock carb and see what it does. I'll then add only 1 mod at a time and see if it helps or not. My other stock engine with slant head and SBP tuned pipe and NT speed carb is a beast and it has a ton of use on it already. It'll pull up the steep hill by my house in 4th gear with no problems. My new engine can barely pull it in first and it is better geared for hill climbing.
 
Hi Drewd, u may have an air leak sumwhere. Check both crank seals. If they're good do a leakdown test. Position piston so both transfers & intake port r slightly open. Bolt a plate (use gasket) over exhaust & 1 over intake with a fuel petcock thru it & either a compression or vacuum guage in spark plug hole. Than pump a small amount of pressure or vacuum into it thru petcock & close it. It should hold that pressure overnight. If not, ur crankcase is leaking. Mine had a leaky gasket new from the factory. Cheers
 
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