Still having problems with a Puch Newport

Motobecane Master /

I posted a few days ago with what I thought was problems with my Puch Newport not shifting into second gear. Well, here's the thing; I now know that it's only a 1 speed bike.

That clears up the possibility of the clutches sticking (correct me if I'm wrong) but the problem still stands.

What it does is it runs fine, idles, starts great, but as soon as it gets to 15-20 mph it starts to bog down. If I keep giving it gas it stops completely. I'm losing my mind trying to fix this thing.

Here is a list of everything I've checked:

transmission fluid changed (added 5.5 oz. of type F)

carb cleaned and assembled correctly, choke slide is staying up

gas mixture is correct (2.5 oz of oild per gallon)

cleaned the air filter and fitted it tight to carb

cleaned the muffler and pipe coming from the engine, there are no clogs

Basically I've done everything I can think of to try to fix the problem.

I know of three problems with the bike, all of which I'm fairly certain shouldn't be doing anything, let alone causing such a loss of power. The carb top gasket is not perfect, it has a rip but it still covers everything. Also, the plastic tube that used to be on the airbox (as far as I can tell from pictures) is gone. That, I've been told, does next to nothing for the moped for good or worse. Last, the cork that used to line the gas cap is gone.

Please please please, I'm willing to stick this thread out and do whatever it takes to get this thing running correctly. It's a beautiful bike and has no other problems (ok, the headlight goes out when I hit the horn button but that's a wiring problem I'm going to worry about once I get the damn thing running right).

I'd appreciate any help, thanks.

Re: Still having problems with a Puch Newport

Sonnds like it might be a gas flow problem, I just got through rebuilding my 1980 Maxi, the petcocks on these things can clog pretty easy, and if the bike set for a while before you got it, you might need to clean it. and be sure to run an in line fuel filter on your bike. also check the screen in your breather box. mine was plugged. mine runs great now, and tops out about 30 with me on it, and I weigh about 230. clean your carb again, if you don't have an inline filter. good luck.

Re: Still having problems with a Puch Newport

Jason Luther /

yeah definatly sounds like a fuel flow problem. pull the gas line off of the petcock and see if the fuel flows freely (say that 5 times real fast)

Re: Still having problems with a Puch Newport

Jason Luther /

also the tube in the back of the airbox does make a big difference. if it is gone, or you remove it, youll have to use a bigger main jet size or it may bog at full throttle. however your problem sounds like a fuel delivery issue

Re: Still having problems with a Puch Newport

Motobecane Master /

Ok, that gives me something new to work with. I'll be working on it tomorrow and I'll get back to you with my results.

Also, could I improvise and just buy 6" of tubing to fit onto the airbox in place of the tube that's missing?

Re: Still having problems with a Puch Newport

Jason Luther /

my maxi is sensitive to temperature differences, so when its a cool season i just duct tape over a sliver of the hole. however once you get it running right, you can buy a bigger main jet and leave that hole wide open for a little more power

Re: Still having problems with a Puch Newport

Motobecane Master /

So I cleaned out the petcock, fuel's flowing freely from there. What I now believe the problem to be is that the tube running from the petcock to the carb is crimped. It looks like it wasn't long enough when it was installed (I don't think it's the original because it has a filter on it) and it's crimped where it had to bend up to the petcock. Fuel goes through it but it may be causing enough blockage to bog it down at faster speeds. Since it's been that way for probably at least a decade I can't get the crimp out completely.

I'm going to look for a new one at a few motorcycle shops around here Monday and see if that solves the problem. If not, it's back to the drawing board.

This is just something else that may help identify a cause for the bogging. I've been able to get the bike to full throttle while on its stand if I ease into it really slow. If I give it full throttle right away it bogs. With me on it (I weigh all of 145 pounds) I can't get it to full throttle at all. Hope that helps.

Again, thanks.

Re: Still having problems with a Puch Newport

Leon Swarmer /

You prolly can get fuel line at the hardware store.

I bought my PUCH for a non -running price. Took it home saw the crimped fuel line, replaced it and it fired up.. Happy guy I was.

Re: Still having problems with a Puch Newport

Also check the vent hole in the fuel cap.

Re: Still having problems with a Puch Newport

Motobecane Master /

Where is that on a Puch? I didn't see one.

Re: Still having problems with a Puch Newport

check banjo inlet on carb small screen in there clogs up all the time and nobody cleans them!!!!!!!!!!!!!

Re: Still having problems with a Puch Newport

That little banjo inlet screen is a whore. Clean that and clean that carb jet again. Be sure to install an inline filter and you'll be good. No inline filter and you WILL have these problems again.

Re: Still having problems with a Puch Newport

Ben Van Zoest /

The ped got to come to a certain speed for the centrifical clutch to kick in, for now because you can't get it up to speed

only starter plate clutch propels you forward. If everything is alright you should feel a slight tug from the working Centri clutch and purr up to 28 mls/hr.

Re: Still having problems with a Puch Newport

Motobecane Master /

I've cleaned all of that crap like ten times. I've also adjusted the needle to where it's performing the best. I've tried letting the thing run a bit without the airbox and that doesn't make it go faster. I've tried staring at it for five reps of ten minutes, that doesn't do anything.

It bogs at full throttle. No matter what. I can go right from idle to full throttle and it bogs, or I can ease into full throttle and then it bogs. If it starts to bog all I have to do is let it off slightly so it's not at full and then it picks back up again. Regardless, it really affects the thing's top speed.

It seems like it's something going on in the carb but I'll be damned if I know what's going on.

Re: Still having problems with a Puch Newport

Motobecane Master /

Also, the jet on the carb is a size 54, which I believe is stock. Would getting a bigger one help any? If so, what size should I try?

Re: Still having problems with a Puch Newport

You are describing _exactly_ what I was going through. I cleaned the jet and installed the inline filter and that cleared it all up. That's what worked for me....

Re: Still having problems with a Puch Newport

Sounds like a plugged exhaust port and pipe

Re: Still having problems with a Puch Newport

Airleak?

Re: Still having problems with a Puch Newport

Motobecane Master /

I'm still working on this damn thing, thanks for the bump. I thought maybe it was an airleak because there is a rip in the carb top gasket. So, I had an extra ripped gasket that I put on there. Now it's double gasketted but sealed all around and it's still having the same problem.

Re: Still having problems with a Puch Newport

It could be an air leak around the base of the intake manifold. That happened to me a couple weeks ago. Make sure the manifold gasket is good, and the two nuts bolting it on are tight. Then, and this may sound obvious, make sure the screw clamping the carb onto the manifold is tight. Then, if neither of those suggestions help, buy one size smaller jet (52), and one size larger jet (56) and try them both. In my experience, running with or without the air filter has absolutely no effect on performance, so don't worry if you don't have a snorkel, but that's just my experience. The amount of air going through is _primarily_ determined by the size of the venturi. If none of those things fix it, check your timing (should be 2mm btdc) and your compression (should be 120psi-140psi).

Hope this helps,

Willie.

Re: Still having problems with a Puch Newport

i have been screwing around with a newport for the past few weeks, with EXACTLY the same problems - i did everything you have done as well, and still nothing. check the cylinder for the type - mine has a 22 on it (the number is on the mating surfaces of the top and botton ends...) this 22 indicates a high compression cylinder - so i checked the compression, and it was around 65psi - way to low for even a standard cylinder... so looking through a couple manuals, i came across a note that the 22 cylinder should have a .60mm head gasket, which is not the standard for puch engines - with the cylinders, damage to the head gaskets can allow horsepower to bleed out, and having to little clearance can change the port timing - while this may or may not make a huge difference, i would say that you should test the compression. if its lower than 120psi, decarbonize the engine, replace the piston rings, head gasket, and hone the cylinder -

Re: Still having problems with a Puch Newport

Ok Ive read all the posts now I can put in my two cents <that little tube on the back of the airbox is very important if its not there and the ped is stock IT WONT RUN I dicked with my maxi for awile after reading your problem I went out took my airbox off took that tube out put it back together and guess what? it boged down when i tryed to give it full throttle sounds kinda familiar NO? so before you dick around anymore I might suggest you rig up a tube and try it or stuff a nylon sock in the hole anything to restrict the flow of air and see what happens experiment whats it gonna hurt GOOD luck with it Dan

Re: Still having problems with a Puch Newport

shit it didnt print well anyway I went out to my maxi and took the tube out of the back of the airbox guess What ? it bogged down when i gave it full throttle ,Paul if I was you I would do a little experimentation and try to restrict the air going in put a tub in it or stuff a nylon sock or something in the back of the airbox also make sure the airbox is sealed around the edges to much air on a stock PUCH will bog it down Dan

Re: Still having problems with a Puch Newport

Motobecane Master /

Hmm, I'll have to try to find some tubing that'll fit on the back. I've tried putting some electrical tape to cover the hole and it helped but it didn't really solve the problem.

Re: Still having problems with a Puch Newport

if it changed the way it ran for the better than i think your on the right track , for some reason it causes just enough resistance in the air flow , its there for a reason these puchs are wicked sensitive ,i increased my air flow slowly by drilling 1/8 inch holes in the air box ,one hole did nothing ,2 holes made it run smoother when warmed up , 3 holes and it bogged down so i covered one up with tape and it runs sweet and those are tiny holes so you can see how sensitive they are, i would try a piece of heater hoce or something like that go to the hardware store and see what they have peaceup dan

Re: Still having problems with a Puch Newport

get rid of the tube and if there is a plug underneath it pull that out too.... those are restrictios.. upjet a couple sizes and I got a Biturbo for my 77 newport and it zooooooms

Re: Still having problems with a Puch Newport

ok, i dont think anyones mentioned this...

the inlet needle that lets gas into the carb, that might not be opening all the way...

i had that problem with my sears(puch) just bend the tab on the float slightly

Re: Still having problems with a Puch Newport

did you ever try a bigger main jet?

Re: Still having problems with a Puch Newport

Motobecane Master /

I'm still waiting to order some. I hate having to order like 8 dollars worth of stuff and then pay the same in shipping.

Still having problems with a Puch Newport

Motobecane Master /

I still haven't yet figured this out completely, however, it's definitely an air/fuel issue. Like I said, taping over part of the air intake on the airbox stops the bogging issue but it still only goes like 20 MPH. It needs to go faster.

One issue I'm dealing with that may be partly causing it is that the muffler will not go on tightly. Does anyone know the size of the nut that keeps the end of that thing on because the one I have can be pulled off with a little effort without even unscrewing it. That makes for a very loose muffler.

Also, I bought some tubing at a hardware store today but there is no way I can attach it to the back of the airbox to restrict air like the original tubing was supposed to do. I'm either going to need to get an original piece that's fitted correctly or I'm going to have to upjet, which I think may solve the problem.

That said, if anyone has any spare jets lying around for a bing carb that are larger than size 52 I'll take them off your hands for the price of shipping and say, 2 dollars each? Otherwise I'm going to have to order them from mopedwarehouse or something.

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