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Trying to mount my carb

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Wiley

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Discussion starter · #1 ·
I have a z50 softtail that I mounted a 110 in. The carb it came with is some sheng way thing - I believe it was a 20mm. I have one of those 12 way adapter plates but am having a hard time finding the right position to mount the carb. It seems as though no matter what way I have the thing mounted, either the tank or the petcock is getting in the way.



The intake manifold that I have has a little twist at the bottom which probably offsets the carb by about 15 degrees or so off center so I can't mount the carb straight back and the petcock hits the air filter. When I use the adaptor the carb sits to tall to sneak in under the frame and the tank hits the top of the carb.



I've looked around at the various sites that I normally get parts from but I can't seem to find any 20mm intake manifolds - am I measuring the wrong end or something? :confused:
 
#2 ·
Start by getting an aftermarket petcock from tbparts.com for your tank. That will make things easier.



The easiest (albeit most expensive) solution is to purchase a G-craft Intake for the PC20 and Shengway 20mm carbs. This swivels 360 degrees on the base and you don't have the additional height with the 12 way adapter/eyesore.



Start with the petcock...
 

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Discussion starter · #5 ·
Ok, so back home from work and I tried to mount it again - was beginning to wonder if I was on crack or something.



There is really only two options for mounting, the first is without the adapter and mostly pointed back, the second is with the adapter and straight out the side.



As you can see, the first option doesn't work as even the side flow petcock that I have comes straight down on the air filter. I suppose I could take the filter off, but since this will be run primarily on gravel I don't really think that's a viable option.



The second option which is one that I've seen used before doesn't cut it either - I'm guessing that my intake is shorter than some other ones as the tank comes down right on top of the carb.



Help!!!! :confused:
 

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#6 ·
look at my z pics at the end 1976 i mounted a 22mm card out the side you need the 12 way and a longer and maniflold, that is lower. other wise you need the gcraft mainifold. but the side look is more of a hot rod look.
 
#9 ·
If it were me.... I'd remove the 12 way plate, then use a cut off wheel and cut the manifold right above the base. Position the carb in the spot you need it, probably where the cable can fit between the frame and tank. Then mark the base and pipe part of the manifold. Remove everything and have someone weld the manifold back up.

I did this one mine and works great. The 12 way plate is probabyl raising it up too much. Add the 12way plate and heat insulator under the manifold and I'm sure it's way too high.

Cutting and rewelding worked for me! Here's a link to another pic I have of the manifold. Link>>>http://www.planetminis.com/f14/petcock-peeves-98070.html
 

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Discussion starter · #10 ·
vegatron75 said:
If it were me.... I'd remove the 12 way plate, then use a cut off wheel and cut the manifold right above the base. Position the carb in the spot you need it, probably where the cable can fit between the frame and tank. Then mark the base and pipe part of the manifold. Remove everything and have someone weld the manifold back up.

I did this one mine and works great. The 12 way plate is probabyl raising it up too much. Add the 12way plate and heat insulator under the manifold and I'm sure it's way too high.

Cutting and rewelding worked for me! Here's a link to another pic I have of the manifold. Link>>>http://www.planetminis.com/f14/petcock-peeves-98070.html
Click to expand...


That is a heck of a good idea. I've started the emails trying to line up the welding resource. :)



I'll let you know how I make out!
 
#11 ·
Wiley said:
I already have one of these mounted on the tank.



Honda Trail Bikes



I noticed this one when I was looking for the petcock - it mentions that it's for use with 20-24mm carbs, but would the intake fit the head?



Honda Trail Bikes



Failing that, what sort of price range am I looking at for the G-craft intake?



Thanks
Click to expand...


Take a picture of your carb. If you have a shengway 20mm carb, then the trailbikes intake will fit the carb.



Also take a picture of your head.



Post 'em up.



Some of the chinese engines have a taller deck height where the intake mounts to the head causing your intake and carb to set higher.



You can also add a spacer 1/4 to 1/2" under the rear mount of your tank to slightly raise it up if you need some additional clearance.



I'm asking for the above so I can understand the variables you are dealing with.



The G-craft intakes run around $88.00. Ask around the forums where people get their G-craft parts.
 
Discussion starter · #12 ·
Z said:
Take a picture of your carb. If you have a shengway 20mm carb, then the trailbikes intake will fit the carb.



Also take a picture of your head.



Post 'em up.



Some of the chinese engines have a taller deck height where the intake mounts to the head causing your intake and carb to set higher.



You can also add a spacer 1/4 to 1/2" under the rear mount of your tank to slightly raise it up if you need some additional clearance.



I'm asking for the above so I can understand the variables you are dealing with.



The G-craft intakes run around $88.00. Ask around the forums where people get their G-craft parts.
Click to expand...


Ok, here are the carb and head.



As far as where folks get their G-craft stuff, I thought that was you? ;)
 

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#14 ·
Wiley said:
Ok, here are the carb and head.



As far as where folks get their G-craft stuff, I thought that was you? ;)
Click to expand...


It is me... I would prefer others point this out rather then blatent spam.



That's not a 20mm carb. Dunno what it is, but looks to be smaller. I'm not adept in the way of the chinese. I have 2-3 of those carbs and I think they are 16-17mm. Not sure.



The mounting point for the carb on your engine is higher then a standard 50cc head.



Here's a pick of a 20mm carb mounted on my 1976 using a Honda engine.



Image




Couple of things why the above pic won't do you any good.



#1. I have an aftermarket aluminum tank with a relocated Petcock that cures the petcock issue. The tanks are bloody expensive and you don't need to go that route.

#2 I'm running a Honda motor that has a lower deck height where the carb mounts.



Back to your combo. The G-craft intake with a suitable 20mm carb may give you enough adjustment to angle the carb enough to sit under the tank and clear the frame. You could also potentially run the carb out to the right if you have a down-type exhaust and move your coil under the seat frame rail. This is where I have mine located. See attached. The coil is actually under the frame rail and the nut on top of the frame is attached to the coil stud sticking up through the frame.



You could also have your intake cut and rewelded in a position that would work for your application and then clean up the weld on the inside of the intake.



If you look at the underside of your tank mounted on the bike, you'll see you actually have more room on the right (as you sit on the bike) then you don on the left. More room for a bigger carb. But, you can't kick out the carb to the right if you have a stock routing exhaust.



Try the cheap fixes first. Space up the tank in the rear by 1/4-1/2" and see if that gets you were you are going. If it doesn't, a G-craft PC20 intake may not fit that carb, and would cause you to get either a Shengway 20mm carb (Trailbikes) or a Keihin PC20.



No easy/cheap fixes (in my opinion) if spacing the rear of the tank up doesn't give you the needed clearance. You could space up the front of the tank by drilling holes in the frame higher where the tank mounts and run a stud through the frame to attach the front tank rubbers to.



Lots of different options to get you where you need to go.
 

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Discussion starter · #16 ·
Z said:
Lastly,



With that longer engine, do you have enough clearance so you don't stuff the tire/fender into the front of the engine?
Click to expand...


Good eye - I actually shaved the front fender back about 1/2 an inch. As far as the tire into the engine, it's very close if I compress the shocks all the way. I'm going to have to source a set of +1 forks at some point but for right now making it move on it's own power is my priority.
 
Discussion starter · #17 ·
nielspbr said:
Nice, a 3-valve unit. (lifan?)

That explains the bigger head and the resulting space problems, especially with a peanut tank.
Click to expand...


I was really beginning to wonder if I was going crazy since hardly anybody else seemed to have these problems. Makes sense when I think about it though!



I actually don't know the brand of the engine - my girlfriend bought it for me last year for Christmas (actually off a friend of tmas - if you read this it's one of Mike's old engines) and I haven't found any markings anywhere that give me an idea of the manufacturer. The closest thing I was able to find just on a picture search was a Loncin but even that was a little different.
 
#18 ·
Discussion starter · #19 ·
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Wiley
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