Puch Maxi Airbox

Crisis--Cincinnati /

I just replaced my 12mm carb, with a 14mm carb. Do I need to use a different sized airbox than the original size. Also,Does anyone know what the white tube, restricting looking thing does, that attaches to the Puch Airbox, and runs into the frame? Thanks.

Re: Puch Maxi Airbox

XBrandon EdgeX /

You can use the original airbox. The white tube basically restricts air. You can cut a couple inches off of it and get more speed without leaning it out too much. Some people even take them off all the way, but I tried that and my bike ran lean and I didn't have any extra jets at the time. If you remove the hose and rejet, though, you're bike will go faster.

Re: Puch Maxi Airbox

You mean get a bigger jet? I just put in a new 14mm carb, I wonder what the jet size is on that puppy? I really don't want to take the carb off again. So, I can just cut off a few inches of that hose and I will go even faster?

Re: Puch Maxi Airbox

ah ... you've begun the complex process of moding out your bike! ... happy speeding.

Re: Puch Maxi Airbox

What exactley does "running lean" mean?

Re: Puch Maxi Airbox

XBrandon EdgeX /

running lean means the air/fuel ratio going into the engine has too much air and not enough fuel. since the oil is mixed with the gas on a two stroke, it's very dangerous for it to run lean because the piston and cylinder and other moving parts won't get enough oil. on top of that, a lean air/fuel mixture also makes the engine run hotter because of the way it burns.

If the air fuel mixture has too much gas and not enough air, this is called running "rich". It's not as dangerous, it will just make it lose power and make the spark plug dirty.

When you modify the airbox to deliver more air to the engine, you have to compensate by letting more fuel get to the engine as well.

Re: Puch Maxi Airbox

So if I cut a few inches off the white hose, will I need to rejet?

Re: Puch Maxi Airbox

XBrandon EdgeX /

Probably not, but keep an eye on it for awhile.

Re: Puch Maxi Airbox

THANKS!

Re: Puch Maxi Airbox

yo if i take my air box off altogether what jet will i have to get?

Re: Puch Maxi Airbox

XBrandon EdgeX /

I don't know, I've never had the urge to remove the box completely. I don't know why you'd want to have no filter of any kind on the carb. But if you want to remove it you'll just have to do the jetting by trial and error. I bought a puch from a farmer who didn't have an air box for it so he used the next best thing, a curved chunk of automotive heater hose :). It really didn't serve a purpose except to keep stuff that was flying off the chain from launching into the carb. But, the bike ran fine without the airbox and I'm pretty sure it was a stock jet. You may not need to rejet at all. I know people that have removed the little white hose on the airbox completely with no problems. On my bike, though, I removed the little white hose and I could feel it leaning out, so I stuck it back in. (I was cruising some country roads and decided on a whim to remove the hose to see how it ran.)

Re: Puch Maxi Airbox

Crisis--Cincinnati /

Not only does the Puch airbox have a white hose, but it also has a plug with a hole in it, (the restrictor). If you take the hose off and leave the restrictor, it runs the same, from my experience. It is like the tube it just there to blow the air towards the front and not right into the side of the frame. I took the hose and restrictor off my Maxi, and I didn't get shit, except my bike had No power. It ran and idled fine, but no exceleration at all. I think I am going to look into getting a bigger jet, and see how that goes. Does anyone know how much a jet would cost?

Re: Puch Maxi Airbox

XBrandon EdgeX /

Yeah, I just got a puch running that didn't have the hose or restrictor and it ran like ass. I didn't have an extra hose or restrictor around so I blocked off half the hole with electrical tape and it runs like a champ!

I've bought some jets from www.themopedjunkyard.com and they're about 6.95 apiece. They're probably cheaper at www.mopedwarehouse.com, though.

Re: Puch Maxi Airbox

Chris--Cincinnati /

I guess I better bust the jet out of mine, to see what I have already, and just buy a bigger size. Right? So, If I unscrew the bowl on my carb, there is that floater donut looking thing. the jet is right in the center, correct? The brass piece that is hollow? Are there any tricks that I need to know to get the jet out? There aren't really too many parts in there right? Give me the low down B. :)

Re: Puch Maxi Airbox

XBrandon EdgeX /

Yeah, you're right on which part is the jet. You should be able to just unscrew it. The screw is just a little tiny screw. Compared to something like a car's carburator, there's very few parts in a moped carb, shouldn't be too bad.

Re: Puch Maxi Airbox

Crisis--Cincinnati /

People talk about taking a few inches off the hose. What good would that do if you still have the restrictor, or with a hose and no restrictor, how would that help. Basically, what exactly is the hose for?

Re: Puch Maxi Airbox

XBrandon EdgeX /

I think the ribs in the hose create turbulence and slow down the air going into the airbox, thereby restricting it. When you cut a couple inches off the hose, it reduces the areas where the air going in will be slowed down. If you have the little restrictor plug in there, pull it out. If you don't really want to rejet though, keep it in and just do the hose cutting thing. If you don't mind re-jetting, get the next 2 or 3 bigger jets in increments of twos (if you have a 56 jet, get a 58, 60, and 62) and de restrict the air passages and re jet. Stock puch jets go in increments of 2's between 56 and 64, but most places can make them any size.

Re: Puch Maxi Airbox

What if I just take off the hose completely, and leave the restrictor? That is how I have it right now, and it is running exactly the same as it was originally, which is good, but no faster without the hose.

Re: Puch Maxi Airbox

XBrandon EdgeX /

If it's running the same as before without a hose, I guess it doesn't really matter if the hose is on or not. Maybe the restrictor completely cancels out any restriction provided by the ribbed hose.

Re: Puch Maxi Airbox

Crisis--Cincinnati /

That is what I have gathered. I don't think the hose really makes a difference. But it must be there for a reason.

Re: Puch Maxi Airbox

Ron Brown /

Chris

Sometimes, air box hoses are simply to keep dirt out of the box and/or move the intake to an area where the air is not as turbulent while riding or in cross winds. On my Batavus, removing the hose that poked up into the area behind the engine seemed to give me less air.

If you really want to know what is happening, make one change at a time and do a plug chop after each change. Write down the results to avoid confusion.

Ron

Ron

Re: Puch Maxi Airbox

So far, I've just pulled the grey house out of the airbox. The hole that it went into measures 15mm. Am I correct in assuming that opening the hole up further (to be closer to the size of the mesh filter) would not make any difference unless the size of the carb and intake is greater than 15mm? I don't want to butcher the airbox unless there is something to be gained. Since this is for my stock sleeper bike, I want to keep the airbox and am not going to change to some other type of air filter.

Re: Puch Maxi Airbox

Overpriced Parts /

some person Wrote:

-------------------------------------------------------

> So far, I've just pulled the grey house out of the

> airbox. The hole that it went into measures 15mm.

> Am I correct in assuming that opening the hole up

> further (to be closer to the size of the mesh

> filter) would not make any difference unless the

> size of the carb and intake is greater than 15mm?

> I don't want to butcher the airbox unless there is

> something to be gained. Since this is for my

> stock sleeper bike, I want to keep the airbox and

> am not going to change to some other type of air

> filter.

You will lose much power and speed if you use stock airbox in any form

It's square and ruins flow. I'm telling you this with about 100 bikes experience Don't use it.

Run this mesh filter like this it still is sleeper

image.png

Re: Puch Maxi Airbox

Wow, a thread from 2001 reading like a couple of virgins talking about having sex for the first time. So innocent. Now you'll be lucky if a thread gets you any type of answer you need, instead resulting in a playground for trolls and dreamers. Great advice Ken.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account