Puch - power loss?

So the throttle cable got really worn out and started messing up. So I order a new one and throw it on. Now it's got a big power loss. I've adjusted everything so the cable is nice and tight (it's the double balled cable, so it's the right length) and from looking into the air intake, it's pulling up enough to let enough air come through.

So what's with the power loss? I can't figure it out. What should I start looking for?

Thanks,

Beamer

Re: Puch - power loss?

Assuming that the throttle slide is opening fully (check this) it's possible that when you disturbed the carb to install the cable, some dirt in the bowl got into the jets.

Re: Puch - power loss?

Okay, I recleaned the carb - clean as a whistle.

As far as I can tell it's opening fully, with the top of the carb off it pulls the slide all the way against it, and looking into the air intake it pulls up enough to not see it anymore. I also tried adjusting the needle.

Though now when I start it ... it goes:

blum...... blum...... blum..... : : dies : :

If I give it a good pedal and get the back wheel spinning whilst I start it... it slowly dies. You can't give it any throttle now.

Re: Puch - power loss?

If it's dying when you try to give it throttle (we say that it "wont take air"), then the engine is getting too much air, or not enough fuel.

Possible that you created an air leak at the carburetor mounting? Wrap the joint in duct tape, and try it. If it works, then remove the tape and find & fix the source of the leak.

Re: Puch - power loss?

Hey Beamer

I hate when that happens! Make sure the choke slide is in correctly.... and pulls all the way up.. you didn't really mess with anything else.. The default setting for that needle is the second notch from the top... but from the sound of it.. it's gotta be something obvious cause those carbs are tough.. they even run fine without the tpo gasket..

By the way.. those double ended cables were discontinued by Puch along with that style throttle...there was a design defect that caused them to pop out... I switched mine to the old style by popping out the pin and swapping it for a screw type.. its just a tiny little part thats easy to switch... and i just cut off the end of the cable and threaded it in..

Re: Puch - power loss?

everything looks just like it should, it's eating my brain. The needle is second from the top like you said. Though I am missing the top gasket, it's screwed in nice and tight. I also never had a top gasket.

Heh why I replaced the cable in the first place is cause it kept popping out. My newport has the screw style which I love. But it's working fine now.

When it does run it sounds like air is being pushed out or sucked in from somewhere. I can hear slight air popping. but I can't tell from where.

Re: Puch - power loss?

those carbs run fine without the top gasket... in a pinch lol... I ran mine for a year without one without a problem..

did you you by any chance take the maifold off?? if you did that HAS to be the problem... it sounds like a leaking gasket... that would cause those symptoms for sure!

Re: Puch - power loss?

I didn't take it off - but that might just be the case. I believe I have an extra laying around - I'll let you know the outcome.

Re: Puch - power loss?

okie

Re: Puch - power loss?

Well it doesn't die by itself anymore with the new gasket.

Here - I recorded what it's doing. it won't go past this - it's at full throttle.

Re: Puch - power loss?

hmmmmm... that's so wierd... it sounds like the throttle isn't opening all the way.. did you try pulling the cable from right at the top of the carb? I'm thinkin it may be in the cable since that's what you worked on.. either that or the end of the cable that goes into the carb may be wrapped around the spring or something or that nature... are you sure the choke is connected to the rod and not just sittin all the way down in the slot? mebbe when you put it together it slipped offa the notch... and it looks like its connected.. but it's really all the way at the bottom.. I need to sleep on this lol... now it's eatin my brain lol

Re: Puch - power loss?

It looks like it's being pulled up all the way no problem. The slide is fully up no question about it. I even took it out at one point.

ARGH! We have a ride on Sunday!

Re: Puch - power loss?

damn.. I pulled mine apart today to clean it and really lookd at it close and I couldnt figure anything else out... those carbs are really simple... it has to be some dirt.. maybe in the banjo bolt... they came with a little screen in there that most peeps took out.. I'd blow the whole thing out with some carb cleaner with a little pipette attached.. let me know this is buggin the hell outta me!

Re: Puch - power loss?

Hehe okay, I'll clean the bastard out again tomorrow. The whole thing was blown down completely with carb cleaner and blown out with an air pressure machine thingy.

I've got the right jet / airbox setup. I think its a 74 jet with a magnum air filter (the bikes actually a Pinto)

I'll keep you updated.

Re: Puch - power loss?

did this bike run fast before you cnaged the cable?? that jet sounds kinda large for that airbox... I have a #70 on my Magnum with a Hi Perf air filter..and a Biturbo. How fast did it go before??

Re: Puch - power loss?

oh is it a 12, 14, or 15mm Bing? and what mm is the maifold?

Re: Puch - power loss?

It would go 32 or so with the 74. Maybe when I pull it apart tomorrow I'll put a slightly smaller jet in there.

Magnums and the smaller bikes use the same carb right? I'm not sure what mm the carb is - how can I check?

Re: Puch - power loss?

there is a number stamped on the sideof the carb... all the original ones were 12mm but they made 14 back then too.. and they are sellin 15mm's now.. there is a number stamped on the side of the manifold too.. the 12mm really restrict speed with a good pipe and open filter... if you upgrade the manifold alone to a 14mm it will make a huge improvement even with a 12mm carb!

Check this out http://mopedarmy.com/resources/articles/bingcarbs/

Re: Puch - power loss?

AH HAH!!!!!!!!

The rider of this bike had stripped the threading on the body of the carb that the float bowl screws into. He swapped it with another carb in my garage ...

... A 12!! His was a 14, and his manifold is a 14 as well.

PROPBLEM FOUND.

So - now to find out:

1) Can I use the 12 on there and down-jet it? the the filter will be off.

2) Is there a way to fix the stripped threading on the other carb? It wont tighten enough and gas leaks out of the seal.

Re: Puch - power loss?

okay... now I'm confused lol..

Whatever you do keep the 14mm manifold... that's key..

Those carb bowls usually strip the threads on the inside of the bowl not the threads on the carb body stem thingy... make sure that is not the case... cause you want to keep the 14mm carb if you can... the bowls are interchangeable..

You wont get the flow with a 12mm as you do with a 14mm... but its more inportant to have a 14mm manifold so you are in good shape there.

check those threads and make sure it's not the inside threads on the bowl that are stripped

Re: Puch - power loss?

The threads are on the stem - not the bowl.

=(

Re: Puch - power loss?

Damn.. I thought you were gonna dodge a bullet on that one but no worries.. I used a 12mm and a 15mm on the same setup with a 14mm carb and the difference was negligible.. and the jet was the same.. so you shouldn't need to change it. is your 12mm a 1/12/293 ??

Re: Puch - power loss?

I meant on a 14mm manifold :P

Re: Puch - power loss?

Yeah, it's a 1/12/293

Should I downjet? But then the filter will be too big.

Is there a way to rig the other carb up for the time being? I'd guess I can't use that hold-tight screw spray in the carb.

Re: Puch - power loss?

That's excellent...

Thats the carb setup that they used with the larger #60 jet... so it will work fine.. I've run the same setup on my 1.5hp Newport and I have it on my Magnum 2 hp now... it works great as is!

Re: Puch - power loss?

I run it with a #60 jet with the 1.5 motor and a 70 or 72 with the 2hp... you may have to go down one size on the jet to compensate for the difference in mm's but if you experiment you will hit it right on the nose.. oh.. both of mine are with either a K&L Hi perf filter and/or the square airbox with the plug out... I wanted to try the Magnum filter I have but it had no filter element in it when I got it and I don't know what to use to put inside of it... or where I can get a replacement element.... any ideas?? I think it'll run even beter with your Magnum filter cause the K&L lets in a ton of air with the 12mm carb..

Re: Puch - power loss?

So I got frustrated and just put a _new_ 15mm carb on it to make it work.

same problem!

It's a 15mm carb on a 14mm manifold with probably a 70 jet. I tried 3 different airboxes, and it just doesn't go over like 10mph.

Should I swap the manifolds to? Or does this problem go much deeper?

Re: Puch - power loss?

dude.. I am really at a loss... I've been backtracking ijn my brain trying to figure out what could have caused this from just changing a cable... it the 15mm doesn't help and you didn't change the jet with the cable then it's not the carb... unless you changed the jet with the cable... the same jet should work well with both carbs... I know it sounds lame but have you checked the plug for fouling?

It does sound like a jet/airfilter mismatch so you may want to try a smaller jet... just to see what happens.. the 1.5 Newport calls for a stock 50 jet and I run a 60 with the biturbo... but the Maxi 1.5 calls for a 60 stock and my Magnum 2hp calls for a stock 60 jet and I run a 70 with the Biturbo... it did the same thing yours is doing when I tried a 72 & 74 jet so either way you may be waaaaaay over jetted... that's what the symptoms sound like to me..

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