Puch Newport - goin' slow

So I just bought a Newport off of a guy, and it drove like an absolute champ. I got it home, and the next day, same thing - running fast as hell.

The next morning I got up, put a little gas in it, and it's going like 25 tops ... and it's struggling to get that. So I figured I had my mixture wrong, so I called the guy that sold it to me, and I did the same mixture he did (original mixture: 2.5oz per gallon. New mixture: 3.5oz per gallon).

I drained my tank fully, ran all the gas out of the carb, and put my new 3.5 mixture in, along with my friends Pinto - still slow, but his is fast.

I pulled off the carb, completely cleaned it, cleaned the screen inside the banjo, and stared at it for about an hour. No luck.

What could this be?

Thanks so much


Re: Puch Newport - goin' slow

You probaly need a new plug. But check all the following;

Puch specs call for 2%, 50:1 or 2.5 ozs per gal of gas.

#.5 is too much oil and is probably fouling your plug. Do a plug chop and see what the tip of the plug looks like. It should be a light toasty tan or grey. If it is black and sooty or oily, clean the plug or best get a new plug. NGK B5HS or BP5HS gap is .018.

Some things to check

Check you tranny, should be 5.5 ozs of ATF type "F".

Also test for a draggng brake by doing a hand wheel spin on front and rear wheel.

Make sure your choke stem on the carb is coming all the up.

Make sure your air filter is securing fastened to the carb and the carb is secure on the intake manifold pipe. Check the two bolts that secure the manifold to the engine casing.

Torque the head bolts to 7.5 lbs in a diagonal pattern

Lube your drive chain and check for proepr tension.

Check your tire pressure

Re: Puch Newport - goin' slow

Jason Luther /

occationally my points will slip to a tighter point gap, and thus my top speed will suffer. when this happens it idles poorly too.-jason

Re: Puch Newport - goin' slow

Okay in my playings around i've done the following -

Put in a new spark plug (425 Autolite)

Done a hand brake check ... seems to be spinning fine ... but this is my first Puch. It certainly doesn't stop quickly.

Chain seems to be tensioned correctly in comparison to my other peds.

My air filter is a little bit loose ... so I tightened it up with a new zip-tie ... still goin' slow.

Things I didn't do

Because I don't know how =)

Torque the head bolts

Check my tranny

check out my reply to Jason reply about the points. I attached a picture.

Re: Puch Newport - goin' slow

I'm not totally sure what they should look like. Here's a picture of mine.

Look alright?


Re: Puch Newport - goin' slow

Jason Luther /

i have never heard of the autolite plug for a moped. i would get an NGK B5HS. as far as the picture of the points, you need to use a "feeler gauge", in order to tell the gap between them. refer to freds guide in the resources section for a good tutorial for check point gaps. my maxi runs best at .018, but runs fastest at about .021". tightening the heads bolts is just as easy as tightening them. they dont need to be super tight.-jason

Re: Puch Newport - goin' slow

Tab Patterson /

Check the exhaust pipe chamber and port for clogs!!!

Re: Puch Newport - goin' slow

Ben Van Zoest /

1. Poor fuel use high octane.

2. choke plate, bend tab down a bit so slider can drag her up for more air.

3. Main jet clogged, the main jet feeds fuel over 3/4 throtle


It sounds like a fuel/air mixture proble.

Re: Puch Newport - goin' slow

I agree with you - my friends bike was doing the same thing ... and then we figured out his choke was pushed down. Pulled it up, and it was back runnin' circles around me. His did the _exact_ same thing - it would get to 25 and just like... discontinue to go any faster.

So with that in mind, I went to town on that area of the bike. I double checked my choke slide and lubed it up. Put a zip tie around my airbox where it attaches to the carb. even tried just taking the damn slide out. Still does the same.

Just kinda weird it does the exact same thing. Except mine just doesn't change.

I will check the jet when I get home though



Re: Puch Newport - goin' slow

Jason Luther /

oh yeah. duh! do the easy thing and check for clogged ports. ;) -jason

Re: Puch Newport - goin' slow

I'm scared I'm going to have to ask this...

But what do I look for with a clogged port? Is it like an obviously clogged hole? or something that I'm going to have to look for. I've never checked a clogged port before.


Re: Puch Newport - goin' slow

That autolite 435 plug is fine

it cross references with the right plug

Re: Puch Newport - goin' slow

Tab Patterson /

You have to pull the muffler off - 2 nuts on the head and a bolt on the side of the bike...remove the nut on the inside back of the pipe. Pull the pipe into two pieces at this point. Then I use a broom handle and a hammer to tap the rear baffle out of the chrome piece from where the muffler split. Once it's out, look at it. You will see small holes throughout it. These need to be clear!!! Then...before you get it back together...look up into the cylinder port and see if its clear or clogged up. Carefully scrape away any carbon build up.

Re: Puch Newport - goin' slow

Okay I'll give that a shot ... what should I scrape it with?

Re: Puch Newport - goin' slow

Ben Van Zoest /

Say beamer what is the mileage on Ur Puch, it sound like we are doing a slow dance around the tree!

Have you raised the carb low speed needle one notch?

I still think U still have an air fuel mixture problem.

Today, I wanted to find out IF 4 stroking over 25 would cure w/h the airfilter cartrige. I had some surprising results, namely poor take-off speed and I am still scrathing my head on this one!

Goto: topic what's the best way to get rid of rust by Trevor

where I talk about the genuine PUCH shop manual.

« Go to Topics — end of thread

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

Login or Create Account