Reeds Not Seating

[#404's Dad]

I am having a heck of a time getting a set of KOSO Carbon Reeds to seat on the DRR cages. I have several cages and 3 sets of the reeds, they seat on one side and not the other no matter how I mix them up or flip them and so on.

Anyone seen this issue yet? This 90 needs to leave here tomorrow and I have no clue what to do, he wants Carbon reeds but I cannot get them to seat properly.

[hotquads1]

could it be a faulty reed?

[#404's Dad]

Originally posted by hotquads1
could it be a faulty reed?

I don't think so Marc, only because I have two sets and no matter how I mix them up it seems that there is one side on each cage that won't seal. I am stumped, its very weird.

[dericsdad]

Did you try to flip the metal hold down plates under the screws? could the plates be causeing the reeds to tip, or is the reedcage not straight. What if you set a straight edge/slide rule against the reedcage surface with the reeds off... is it flat? I'v had this problem before, and just flipped the reeds and they sealed.

[#404's Dad]

Originally posted by dericsdad
Did you try to flip the metal hold down plates under the screws? could the plates be causeing the reeds to tip, or is the reedcage not straight. What if you set a straight edge/slide rule against the reedcage surface with the reeds off... is it flat? I'v had this problem before, and just flipped the reeds and they sealed.

I've flipped them, swapped the limiters and everything else I could think of to do and still the one side on each cage will be open enough to see light through. If I back the screws off they will seal up pretty good. KOSO fiber glass reeds seal up fine on them.

Its a very strange deal, I can take the carbon reed that "Is" sealing off and place it on and it will too be open.

I am damn near ready to give up on them lol.

[dericsdad]

You may have to tune it also when you put in carbon fiber reeds. I had to change the pilot to get ours to run good. They may still seal... as the crankcase pressure increases, it will push the reeds closed.

[ecmini1]

Sounds like the reed cage is the problem. The cage is warp.

[machwon]

How big of a gap is it. I've had different reed cages from other motors that would do the same. The gap would be about the thickness of the reeds but it really shouldn't make a difference in how it runs. The crankcase pressures should open and close the reeds when it needs to. Otherwise I would bend the metal reed stops slightly in to help close the gap. Sometimes if those get bent outward they pull the reed tips out as well. Hope this helps. Bob.

[#404's Dad]

Originally posted by machwon
How big of a gap is it. I've had different reed cages from other motors that would do the same. The gap would be about the thickness of the reeds but it really shouldn't make a difference in how it runs. The crankcase pressures should open and close the reeds when it needs to. Otherwise I would bend the metal reed stops slightly in to help close the gap. Sometimes if those get bent outward they pull the reed tips out as well. Hope this helps. Bob.

Yep Bob its about the thickness of a reed pedal. I have tried tweaking the stops with no luck, I thought the same as you that they were bent or something. A couple of you have said it should be fine so i am gonna give it a try and see, My fingers are crossed and I greatly apreciate the help.

Corey

[wrhracing]

Cut a piece of the old reed, drill holes, lay on top of the new reed, bolt the stops in place, this will act as a stiffener, smooth the edges well.
I don't think you will notice the difference in performance if that is all the gap it has .
Realtime pictures show the reeds do not close and seat all the way down at higher rpm any way. Nor do they open 10mm. more like 6 to 8 mm.
The real time on Boysens show both petals open at upper RPMs'.
Pretty cool to see.

[#404's Dad]

Seems to start and run perfect so ya'll was right lol.

Now I just need to work on the clutching a little and she'll be fine I think.


Thanks everyone for the help.

[wvspeedfreak]

Originally posted by dericsdad
You may have to tune it also when you put in carbon fiber reeds. I had to change the pilot to get ours to run good. They may still seal... as the crankcase pressure increases, it will push the reeds closed.

Which way did you have to go on the pilot after you installed the carbon fiber reeds?

[dericsdad]

You may have to go smaller on the pilot jet size, as the carbon fiber reeds open up a little faster. But you may get by with just raising the needle clip position (Which drops the needle down into the pilot further) just like the instructions with boyseen reeds say.

[#404's Dad]

Originally posted by dericsdad
You may have to go smaller on the pilot jet size, as the carbon fiber reeds open up a little faster. But you may get by with just raising the needle clip position (Which drops the needle down into the pilot further) just like the instructions with boyseen reeds say.

Not being a smartass at all dericsdad but the Needle goes into the Main jet at the end of the imulsion tube, The Pilot jet is a whole other circuit.

[dericsdad]

You are correct, but the needle clip position does affect the 1/8 to 3/4 throttle mixture. If you read the instructions with Boyseen reeds it explains you may need to change the position. If it is way out of wack at just off idle, then the Pilot needs to be changed.

A good reference for tuning your carb can be found at:

http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf

Hope this helps, Dan