cRanbrook build

Spare_Parts

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So for future reference what does an emulation tube with more holes do? Also, while looking around for power jet tuning tips I noticed a lot of talk of drilling various holes to a larger diameter. Is that only for the oko clones?
 


FNTPuck

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So for future reference what does an emulation tube with more holes do?
More air to mix with more fuel.

Emulsion tubes control the air fuel mixture by adding additional air to the fuel mixture based on a pressure differential with the outside atmosphere. While the gas flows around the emulsion tube, air flows down from the top and out of the little holes to mix with it. As the gas level lowers in the float, more and more of the holes are uncovered to allow more and more air to mix with the fuel and can help keep a big carb from going too rich at WOT.
 

Spare_Parts

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So would that mean a smaller jet could be used with the emulation tube with more holes? The last setup left me running a little rich wot because it wanted a jet in between sizes. Probably could have fixed that with a different needle but never did. Anyway, just curious. Still learning about carbs lol.
 

Spare_Parts

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Hope so.

Picked up some precision files today for working on the transfers. Trying to decide if I'm getting cartridge rolls for the porting or not. Don't know how to tackle the sleeved cylinder. My thinking is it will end with a low spot behind the sleeve using burrs. Anyone have any thoughts?
 

Spare_Parts

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What did you do to that poor cylinder??? I see a hole where none belongs...
Was drilling holes for set screws and went right through the sleeve. New one is already ordered. Took the ruined cylinder over to the 20 ton press and that sleeve is in there pretty friggin tight. It also has pretty rough groves cut into it.

Did get some work done today. Pulled the cables and wires through the frame. Cut the steerer tube cut down. And I swapped out the 18t freewheel for a 20t. The old one was still in great shape. ACS paws freewheels are great. The seating position makes it hard to put enough power for take of. Think the front sprocket is a 42t.

 

FNTPuck

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Was drilling holes for set screws and went right through the sleeve. New one is already ordered. Took the ruined cylinder over to the 20 ton press and that sleeve is in there pretty friggin tight. It also has pretty rough groves cut into it.

Did get some work done today. Pulled the cables and wires through the frame. Cut the steerer tube cut down. And I swapped out the 18t freewheel for a 20t. The old one was still in great shape. ACS paws freewheels are great. The seating position makes it hard to put enough power for take of. Think the front sprocket is a 42t.

I'm sure you can still run that cylinder. Once the set screw is in there you can just make sure the edge is beveled to not catch on the ring and it will be fine. With screw installed as close as you can get it to flush without sticking out, the volume and size of that little hole will not be enough to effect performance. As long as there are no burrs to snag on the ring it won't hurt it - I've ran way more damaged cylinders while testing crap. Plus its so high in the cylinder it looks like will only touch the top ring, and the bottom ring likely won't even reach it so compression won't be affected. Measuring the wear marks on a beat up cylinder the top ring goes as close as 5.1mm to the deck with a single base gasket and the distance between the top of the top ring and top of the bottom ring is 4.5mm so you have ~9.5mm from the top deck before the bottom ring even touches that part of the cylinder. Judging by my uncalibrated eye, the bottom of that hole in your cylinder is right around 8mm so it will hit the top ring, but not the bottom.

If it really bothers you, just fill it with a drop of weld and use a rotary sanding bit to smooth it out - its steel lol.

Either way, don't throw it out if you don't want it, I'll cover shipping to take it off your hands lol.
 

Spare_Parts

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I already pressed the sleeve partially out to see how tight the are. If it is pressed back in the fit may be loose. The intake has also been epoxed shut. Thought about just sticking the grub screw in and saying f*** it but that kinda stuff bugs the hell out of me. If I can press it back in straight I'll let you know.
 
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