extremeodd
Active Member
- Local time
- 11:57 PM
- Joined
- Mar 30, 2019
- Messages
- 284
It's been a while since I've posted anything here, the bike has been running great and my time has been spent on a couple of different motorcycle projects.
Got a wild hair the other week and decided to see if I can't take advantage of the 21mm carb I'm running a little more by ordering a windowed high pin piston from mzmiami and 'g2' reed valve from aliexpress.
Now that they are both here I figured I should get around to installing them, so later this afternoon I will be doing just that. Since everyone reports sealing issues with this reed I will be picking up some permatex of some variety to make sure that I don't have that problem. The installation will be simple enough and I'm not worried about that, hell while I'm in there I might see about matching the case transfers to the head as they are really far off.
The thing I'm wondering about is how much jetting am I going to have to throw at this compared to where I'm currently at. From my understanding, you lose a fair bit of fueling by going from port to reed valve as the air only goes through the carb once instead of three times so I should need to jet up but is it just a little or a lot?
Currently, I'm in a weird spot with my setup as this carb is far too large for this build. Like when I ride around I NEVER need more than 1/8 throttle to accelerate up to speed and I just barely crack it open to maintain 30-35mph. I'm hoping that a reed + windowed piston might help out some by smoothing out how twitchy the motors response can be and hopefully give me some better low-end as there is none to speak of.
Engine details:
Zeda 80 'poorboy' from zeda motorsports back in March '19. Basically an off the shelf zeda80 with the jug ported to the maximum a consumer can easily tune for.
Accidental "opened up transfer mod" from piston ring catching transfer lip. AKA One transfer has a quarter-sized piece broken out of the wall on the jug, after cleaning it up it still runs great.
Generic CNC "high compression" head
~.5mm copper head gasket
mzmiami cnc wide bore 40mm intake (like the normal ones but super bored out)
mz65 pipe
Dellorto PHBG 21mm racing clone with proper au atomizer
Probably should replace the jug but I really can't be bothered as that means buying a bunch of tools and learning how to port the new one. Chances are I'll need to sell the bike sometime in January so I just want to check out what a reed will do for this build. I'll update this thread in a few hours with some pictures of how the bike sits right now and as I make some progress. I'm bad about taking pictures while working because I don't want to touch my phone with filthy hands.
Got a wild hair the other week and decided to see if I can't take advantage of the 21mm carb I'm running a little more by ordering a windowed high pin piston from mzmiami and 'g2' reed valve from aliexpress.
Now that they are both here I figured I should get around to installing them, so later this afternoon I will be doing just that. Since everyone reports sealing issues with this reed I will be picking up some permatex of some variety to make sure that I don't have that problem. The installation will be simple enough and I'm not worried about that, hell while I'm in there I might see about matching the case transfers to the head as they are really far off.
The thing I'm wondering about is how much jetting am I going to have to throw at this compared to where I'm currently at. From my understanding, you lose a fair bit of fueling by going from port to reed valve as the air only goes through the carb once instead of three times so I should need to jet up but is it just a little or a lot?
Currently, I'm in a weird spot with my setup as this carb is far too large for this build. Like when I ride around I NEVER need more than 1/8 throttle to accelerate up to speed and I just barely crack it open to maintain 30-35mph. I'm hoping that a reed + windowed piston might help out some by smoothing out how twitchy the motors response can be and hopefully give me some better low-end as there is none to speak of.
Engine details:
Zeda 80 'poorboy' from zeda motorsports back in March '19. Basically an off the shelf zeda80 with the jug ported to the maximum a consumer can easily tune for.
Accidental "opened up transfer mod" from piston ring catching transfer lip. AKA One transfer has a quarter-sized piece broken out of the wall on the jug, after cleaning it up it still runs great.
Generic CNC "high compression" head
~.5mm copper head gasket
mzmiami cnc wide bore 40mm intake (like the normal ones but super bored out)
mz65 pipe
Dellorto PHBG 21mm racing clone with proper au atomizer
Probably should replace the jug but I really can't be bothered as that means buying a bunch of tools and learning how to port the new one. Chances are I'll need to sell the bike sometime in January so I just want to check out what a reed will do for this build. I'll update this thread in a few hours with some pictures of how the bike sits right now and as I make some progress. I'm bad about taking pictures while working because I don't want to touch my phone with filthy hands.
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