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Post by scoot4t on Feb 26, 2013 15:02:03 GMT -5
Hello every1, I'm just thinking about porting my stock 50cc head, (in / exh) and I have a question, how will the power increase? Ofcourse exhaust pipe will be bigger, and maybe carb 14mm, instead of 12mm. Will I feel a difference?
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Post by 90GTVert on Feb 26, 2013 17:11:05 GMT -5
The simple stuff to do is just to port match your intake, spacer, and head to each other and match your exhaust port outlet to the header. You prob won't see big gains, but it can be a cool project if you like to tinker. You shouldn't need to change the carb, other than making sure it's in tune after your mods. A standard GY6 50 carb should already be around 18mm.
If you want another easy mod, you can try elongating the mounting holes on the pickup coil to allow you to advance ignition timing a couple of degrees. You will likely feel an improvement from that, but you will need to use premium fuel and you should no do this if you already have a CDI with timing advance.
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Post by 89CamminGT on Feb 26, 2013 18:07:09 GMT -5
Im going to put my 2 cents in, but take it for whats its worth.. which isn't much lol
I ported on a 150cc head so yours of course, will vary.
I removed the valves in mine and basically smoothed the ports out and smoothed the transition under the valve seats. I also went and flattened the boss for the valve guide.
Most important is to make sure the ports step UP on the way in from the carb to the head, then step up as well from the head(exh side) to the headpipe so you avoid reversion.
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Post by 90GTVert on Feb 26, 2013 18:57:23 GMT -5
Be very careful around the valve seats if you start working deep into the ports.
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Post by scoot4t on Feb 27, 2013 14:55:42 GMT -5
Thanks, I'm going to give it to experienced person and he will port it so should be well done, I have stock CDI so will have to buy with changing ignition...and how much should it burn with carb 18mm? More than 3l / 100km?
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Post by 90GTVert on Feb 27, 2013 15:19:31 GMT -5
That gas mileage sounds about right.
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Post by scoot4t on Feb 28, 2013 10:23:47 GMT -5
but approximate with average porting?
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Post by 90GTVert on Feb 28, 2013 11:07:01 GMT -5
Prob won't change a ton. I'm more used to miles per gallon and your numbers come to just over 78MPG. The last 4T I owned I took to 80cc with a cam, big valve head, aggressive CVT setup, etc... and even with me at 300lbs I still saw over 60MPG. I don't think just porting the head will make a huge jump.
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Post by scoot4t on Feb 28, 2013 13:23:59 GMT -5
thx and what about a conical filter? I think the stock one can be too small for 18mm carb...
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Post by 90GTVert on Feb 28, 2013 13:31:51 GMT -5
UNI filters are popular upgrades. They make a little difference, but be sure to install an even larger main jet and prob pilot jet as well. You'll have to do something with the crankcase vent that routes into the stock airbox. 49ccscoot.proboards.com/thread/997/crankcase-venting |
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Post by scoot4t on Feb 28, 2013 15:47:42 GMT -5
aaa I see you're right
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