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Homemade Reed Valve on Cheap


Discussion at Motorized Bicycle Engine Kit Forum in the High Performance Bicycle Engine Tips forum. After seeing Sharkcruiser's thread Reed Valve on the cheap, I was inspire to do one myself. So I bought ...
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  #1 (permalink)  
Old 07-14-2009, 12:21 PM
Pitchfork311's Avatar
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Default Homemade Reed Valve on Cheap

After seeing Sharkcruiser's thread Reed Valve on the cheap, I was inspire to do one myself. So I bought a cheap chainsaw reed valve, 8$ and am going to machine a plate that will go between the reed valve and the engine. It will be one piece and bolt right to everything. Of course, I am going to have ti figure out a new intake as well so this project will take a few weeks.

What you guys think,

Pic of the valve I picked up.
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Old 07-15-2009, 01:11 PM
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Default Re: Homemade Reed Valve on Cheap

I think thats great! I am no mechanical engineer but the valve I used came from an engine that was exactly half the cc's but turned twice as many rpm's and made twice the HP. It really helped the reliability of my tired old engine and after rejetting the carb, it made a tremendous difference in the low and mid range power. Can not wait to see how yours turns out. Good luck! Watch out for the bugs you'll catch from the huge grin you'll be wearing!
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Old 08-11-2009, 12:28 PM
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Default Re: Homemade Reed Valve on Cheap

Well, I have been incredibly busy with work, this project ended up getting put aside for the last few weeks. Well, I am hoping to get back to it sometime this week I still cannot wait to put it on my bike, after reading all about your gains shark
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Old 08-12-2009, 11:22 AM
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Default Re: Homemade Reed Valve on Cheap

That sounds great, I can not wait to hear about your experience. I am breaking in a new motor currently and I plan on doing a port job on the cylinder with the reed on it and switching the whole thing over to the new bottom end.
Where I live it has been about 100 degrees and 95% humidity so I haven't been riding that much. Keep us posted!
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Old 08-12-2009, 07:28 PM
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Default Re: Homemade Reed Valve on Cheap

Well, I was finally able to get some free time today at work and machined the bracket. I opened up the side to the engine as big as I could to match the port. I machined the other side to match the reed valve. Then I used a key cutter to open up the inside of the bracket between the 2 surfaces to allow for the maximum air flow. While I was at it I also ported the reed valve hole to just about match the inner diameter of our intakes. The only thing left is to fit it to my bike, and see what customization I have to do with the intake. Im hoping that if I have to do anything, it will only involve moving the air filter. cross your fingers. I will look at this friday and this weekend and get back to you.
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homemade-reed-valve-cheap-0812091614.jpg  homemade-reed-valve-cheap-0812091615.jpg  homemade-reed-valve-cheap-0812091615a.jpg  homemade-reed-valve-cheap-0812091616.jpg  homemade-reed-valve-cheap-0812091626.jpg  

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Old 08-13-2009, 09:05 PM
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Default Re: Homemade Reed Valve on Cheap

that's amazing. great work. you can easily get that to work well w/some tweaking ......in my experience, that round intake hole may be smaller than a nicely ported intake port on the cylinder. On my cylinders, that round hole would restrict air/fuel flow into the motor as the port is way bigger. I may be looking at that wrong, if so my bad.

DD
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Old 08-13-2009, 11:22 PM
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Default Re: Homemade Reed Valve on Cheap

Ya, the outlet hole I purposely cut bigger than the intake, its actually bigger than the intake port on the engine, I thought it all through. I even ported the reed valve to match the intake ID. I wanted to do this right. The only thing restricting the air is the reed valve, it forces the air to take an almost 90 turn to go through it. But, from my experience, with the reed valve to keep the air in the cylinder, you see more improvement than with unrestricted flow. Because w/o the valve, the cylinder causes the air to pulse out. The valve prevents the pulse. Ill keep you all posted as to how it goes. Will hopefully install this weekend
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Old 08-17-2009, 05:34 PM
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Default Re: Homemade Reed Valve on Cheap

Please Post the part numbers and where you bought these reed valves !!!!!
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Old 08-17-2009, 06:07 PM
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Default Re: Homemade Reed Valve on Cheap

Yes part numbers please!
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Old 08-17-2009, 11:10 PM
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Default Re: Homemade Reed Valve on Cheap

Well done Pitchfork! I had not viewed your pictures until this evening. Looks professional.

As for part #'s for spad and goat all I can tell you is that my reed is for the homelite super2 33cc. It can be found on ebay for about $5.00. Although mine came out of the trash for free. I would recommend the small engine repair shop. The one near my house has piles and piles of old chainsaw guts ripe for the picking.
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