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Discussion Starter #1 (Edited)
So, I ground a flat spot at an angle on my drill press with a Bitmoore X Y vise & 4 flute end mill, Cam2 & Nick, you know what I'm talking about. Then a 6.5mm hole for 5/16" x 24 NFT Male Tap. Put the threads in. Any tube with 5/16" x 24 threads will work. I use a 90 degree 1/4 ID brass hose fitting that I had here and next will drill at a steeper angle so the fitting stands up more.
Might be able to squeeze a 3/8" thread in also. The OD of that piece barely had threads cause it was alittle small in diameter, so I got my JB Weld, glued it in place, letting it dry after heating the manifold w/ my Hot air gun to help it set.
The pulse hole was drill to .125" and the manifold hogged out on the inside, and surfaced, on both sides. You can tell your done when you can see you face in the part surface,lol,lol, its True. 400 and 600 grit on a surface plate does Wonders.
 

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nice work man, that's a pretty part. i finally got all of the parts we talked about installed on the bike. it is truly staggering what a huge difference it made, this bike is mean now.

thanks again for your help and keep up the good work.
 

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Discussion Starter #3
Do you have a boost bottle yet, got to have it with that WT 813, I think thats what you got. Its a Kick Azz Carb, my scooter got squirrelly on me yesterday going up a hill on pavement, WOT, had no steering, I was asphalt surfing,lol,lol.
 

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Real nice job EPR...........Its good to see youre getting more creative by the day.....Keep up the good work........
 

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Discussion Starter #5 (Edited)
Dude, got the basic idea from you and your photos, and we talked, and you said you wish you would have used the chamber for more boost.
Next time I know you will mod it some more. My plan is to find some copper or brass tubeing that will take a 5/16" x 24 male threading on the outside, then thread it into the manifold using Yamabond or blue Loc-Tite, them & JB Weld have become good friends,lol. Also want to try to fit a 3/8" x 24 fitting into the next one, for a bigger ID tube. Will bend the tube also.
This one is going on the Lucky 7 cause the bottle is not hooked up, thats why I spent half the day looking for stuff I could not find.
 

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Dude, got the basic idea from you and your photos, and we talked, and you said you wish you would have used the chamber for more boost.
Next time I know you will mod it some more. My plan is to find some copper or brass tubeing that will take a 5/16" x 24 male threading on the outside, then thread it into the manifold using Yamabond or blue Loc-Tite, them & JB Weld have become good friends,lol. Also want to try to fit a 3/8" x 24 fitting into the next one, for a bigger ID tube. Will bend the tube also.
This one is going on the Lucky 7 cause the bottle is not hooked up, thats why I spent half the day looking for stuff I could not find.
Well Im glad you finally gone ahead and did it.......I remember when you asked me a long time ago about the boost bottle and purgeport info and such.........Back then I was a bit incoherent at times because of the steroids and the meds for the leg so I figured you were a bit skeptical or playing it safe;;;I would of been too,,,,,,...........lol

Great job getting it done though..You knocked it out of the park..........Keep us updated on how it performs for you....
 

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Discussion Starter #7
To be real honest, I was afraid to try cause I did not have a mill to bore straight down the into the manifold from the top, and if I did the ID of the tube would be about 1/8". So, after reading your stuff I looked again. I put a fitting at an angle from the side and marked the angle w/ my trusty Sharpie Laundry Marker. Clamped in the vise, with the mark veritcal and put the flat spot. Then you change to the drill size you want, tap it and clean it up. Two times I almost mess up, 1 have 4 manifolds and 4 Walbro carbs, No extras,lol,lol. Thanks for your Help, Cam2
 

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To be real honest, I was afraid to try cause I did not have a mill to bore straight down the into the manifold from the top, and if I did the ID of the tube would be about 1/8". So, after reading your stuff I looked again. I put a fitting at an angle from the side and marked the angle w/ my trusty Sharpie Laundry Marker. Clamped in the vise, with the mark veritcal and put the flat spot. Then you change to the drill size you want, tap it and clean it up. Two times I almost mess up, 1 have 4 manifolds and 4 Walbro carbs, No extras,lol,lol. Thanks for your Help, Cam2
No problem EPR.................Beleive it or not I did the drilling on mine with a cordless DeWalt 18v handdrill starting with a 1/16" drillbit and stepped it up...It was too hot to break out the drillpress and i didnt feel like leaving the cool 65 degree indoor temps................I wasnt worried ,,,My Lincoln mig welds aluminum aswell so if I messed up I could fix it good as new......

Keep up the Great work..............
 

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Discussion Starter #9
Yeah, I have done that. On my FC crank 12mm B/B engine w/ the Dave's 4 port cylinder I marked the piston w/ a Sharpie pin, used my spring loaded center punch to mark it, and did like you started with a small drill bit up to 3/8" eye balling. Was within .010" of the hole positioning, cause I was too Lazy to get my drill press and tools out. I was done before I could have set up. I do like you and have battery, air, and cord drills set up with tools and Go To Town. Hate when I have to stop to find tools or change bits,lol,lol.
 

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Discussion Starter #11
Got the boost manifold on the L7. I put a bigger notch in the butterfly plate, might be to much, wants to idle too high even with the idle screw out and the clutches are draging on the bell at idle. Its a 3 shoe hp clutch w/ racing springs. Had it off, after I almost smoked the clutches and bell housing. Sanded the shoes and bell, put it back doing the same thing again, so its back to work. But the boost fitting works great.
 

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EPR
The cag engine will most likely be restricted by the wt608, at least on the top end. It might be the reason you have too many rpms on the bottom end as well. You might want to try the carb off of the goped gp460 engine, it has a larger bore & venturi. You will need to modify the bore on the manifold and add another port for the pulse port. Its the HDA-223, and "yes" to your next question.

Hugh
SDscooters
 

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Discussion Starter #13
Thanks for the input. It might be the engine not running right too. Seen the HDA-223 and have looked at the HDA-48. My 603 reps have the choke plate taken out, and a 19mm V-stack and choke set up w/ hp filter.
I have 2, 19mm Dell rep carbs and Cag manifolds here also, but need to make alittle smaller main jet. Cause a .94 is too big for my engines.
I put a WT813 on my 49cc piston port scooter, and no problems at all.
I am still learning about these walbro type carbs.
 
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