Puch: High Idle, Sluggish at start.

Sluggish Puch, High Idle. Gets up to speed but has absolutly no low end..none! I have to pedal from a stop. 1 Speed engine

How does air blowing back up out the carb from the compression sound? Possible?

I have a 1/15/46A with a 66 Jet, stock pipe. The 64 Jet boggings and cuts the engine at full throttle. Goes about 30mph after a very very slow start.

Other things I notice: The Carb is covered with gas after riding. The carb is clean as I cleaned it. There does not seem to be an air leak at the Intake. How does air blowing back up out the carb from the compression sound?

Any suggestions?

I just took off the head and cylinder and changed the head gaskets. The rings are in good shape and the cylinder is very clean.

Re: Puch: High Idle, Sluggish at start.

sounds like you are overjetted.... my Newport does the same thing with anything larger than a 60 jet..(with the plug out on the back of the airbox or a Hi Perf a/f) or a 58 jet with the plug in and that's with a Biturbo... the stock jet is a 50 with a Stock pipe and the plug in the airbox..

When I was running a stock pipe.... I had a 60 jet in it and it did the exact same thing you describe... try a 54...52... or a 50 and I bet it will take off just fine when you twist the throttle open!

It also makes a difference what size manifold you are using... I got better low end with a smaller (12/14mm) intake than with a 15mm and the 15mm carb really dumps a lot of gas in the piston... it may run better with a 12 or 14 with the stock pipe!

Re: Puch: High Idle, Sluggish at start.

this is still the newport right fred

did you put the 15 back on from the black puch nostalgia?

i dont think jetting is necessarily the problem, i have run the same size jets on almost the same stock set ups as your describing, i wouldnt rule out a jet problem, but i dont think thats the issue, and you use to run this setup and the same jet and it ran fine right?

how do you know the rings are good? whats your compression, i seriously think its a compression issue or maybe a clutch problem, if its idleing high it could be because there is no resistance from the clutch or whatever and so the engine idles really high yet the bike doesnt move because the pads arent enguaging the drum

i have a couple sets of the fat puch rings i believe if you want to switch your rings,

Re: Puch: High Idle, Sluggish at start.

Steamboat Aka J. R. Stevens /

High idle may indicate a intake air leak. Jim.

Re: Puch: High Idle, Sluggish at start.

there are several different Puch 1.5 hp jet setups..

1/12/293 = Maxi 1.5 HP main jet 60

1/12/309 = Maxi Luxe 1.5 HP main jet 48

1/12/321 = Sport MKII and Newport 1.5 HP main jet 50**

The carb size doesn't make that much difference... it depends on the engine... I've tried a 12mm and a 15mm on my Newport 1.5 hp with a 12/14/15mm intake and the jets were the only factor that significantly changed the performance... and the plug in/out of the back of the airbox!

Re: Puch: High Idle, Sluggish at start.

those numbers are just factory reference points, i never really go by them, what matters is if your plug looks good and your bike runs well, i have never run anything less than 62 in any of the puchs i have owned or worked on, thats not to say that a puch wouldnt take a smaller jet, i just have never needed anything that small

an air leak is a good guess as well,

Re: Puch: High Idle, Sluggish at start.

um... so what you are saying is that all Puchs regardless of different piston and head types.. use the same jetting??

Re: Puch: High Idle, Sluggish at start.

no, i never said that once, i dont know where you read that, what i did say was that the bing carb jet charts are almost irrelevant

to tune your bike to some factory chart thats almost 30 years old seems ridiculous to me, what matters is when the owner of the bike, or the person tuning it is out on the road trying different jets and air intake setups, among other things

Re: Puch: High Idle, Sluggish at start.

I don't understand why you say the Factory specification charts are irrelevant.. of course they are 30 years old but so is the engine they are designed to reference... The techs that designed the engines and wrote the charts were not idiots lol....

There is obviously a huge difference between a Maxi that calls for a 60 stock jet and a Newport that calls for a # 50 stock jet or a Maxi Luxe with a #48 for that matter... I have tried every combination of carb/jets/intakes/air filters on my NEWPORT and I'm here to tell you the setup works the best for stock is the correct jet in the chart!

Newports are not Maxis!

Re: Puch: High Idle, Sluggish at start.

Main jets affect mixture near wide open throttle.. If you've got problems at part throttle, look elsewhere.

Ignition seems ok.

Part throttle mixture is probably really rich. If the carb has a jet needle, lower it a notch. This will lean mid-throttle mixture. Check the float for a high float level. Check the float needle and see if it's leaking.

Some spitting of fuel back out the intake could mean a couple things. Sometimes it's normal and a matter of intake port timing.

But if the bike is sluggish at low speed there's a good chance the carb is bleeding extra fuel into the intake for some reason. The bike runs like a dog while some of that extra liquid fuel is pushed back out the intake.

Re: Puch: High Idle, Sluggish at start.

all i am trying to say is that i am going to go with my spark plug over some chart i found on the internet when trying to tune my bike, allthough my particular moped may call for a specific jet, if that jet produces dark plugs and my bike runs better with a bigger or smaller jet, than i am going to go with what makes my bike run well, not with what some stupid piece of paper tells me to,

further more mopeds were heavily de tuned to stay within state regulations, the techs who designed them may not have been complete idiots, i say complete because there are some things they oviously missed, like transfer cuts on pistons partially blocking the ports, manuals and so forth are good places to start, but for me they only provide a good place of reference, when it comes down to it, if my bike isnt running well with the stock setup, then i am going to do something to make it run better, not keep it as the book says

Re: Puch: High Idle, Sluggish at start.

Steamboat Aka J. R. Stevens /

http://insiderracingnews.com/jf010603.html Hey Brett NASCAR also uses plug chops but they call them clean cuts. Jim.

Re: Puch: High Idle, Sluggish at start.

First of all I am not using some piece of paper I found floating around on the Internet... I am using my original Puch dealer's service manual lol... and second of all the only restriction on fred's setup is the stock exhaust which isn't meant to handle a 64 or 66 jet.... especially with a 15mm carb and a 14mm manifold.... of course if he was running a Biturbo it would be a different story.. and I think he had one on that ped before he put the stock one back on...

All I know is that when I had my Stock pipe on my Newport before I got my Biturbo I mistakenly ran a #60 jet because I listened to someone who was talking about a Maxi and it ran just like fred's is now... (and I was running a 15mm carb and a 14mm intake)... as soon as I downjetted to the stock 50 it ran like a dream..

All I was suggesting was that he try the correct stock jet and see what happens.. its not that hard to change a jet... before he starts thinking about pulling pistons lol...

Re: Puch: High Idle, Sluggish at start.

hmmm thats a really cool article, thats interesting about positioning the plug so the spark is aimed at a certain point in the cylinder,

Re: Puch: High Idle, Sluggish at start.

I am going to check out the gasket on the manifold. It looked okay the other day when I was checking everything out but you never know. I might just make a new one anyway and see what happens. It definelty sounds like air is leaking somewhere when I engage the clutch with no spark plug, sounds like air is coming back throught the carb or leaking around that area..

Re: Puch: High Idle, Sluggish at start.

Jason Luther /

when was the last time you changed your trans fluid? type f. the wron or old nasty fluid will give crappy acceleration since the clutch requires specific viscosity.

Re: Puch: High Idle, Sluggish at start.

I had the same problem yesterday after i pulled the carb a few times to change jets... I finally realized that the black rubber boot on my Hi Perf air filter had a huge split in it inside on of the accordion seams... it was driving me crazy till I noticed it....

fred.... I have a few extra manifold gaskets if you need one.. I just replaced mine on the Magnum cause I just got a tall 14mm intake today and installed it .. I can shoot one over to you! let me know.. I just got back from a ride to the Sq. ans I'm always up for a trip to AuBon Pain for a coffee and I'll meet you there lol

Re: Puch: High Idle, Sluggish at start.

That would be awfully nice of you! I am working the door at the Abbey tomorrow night so I will be there from 7:30ish - 1:30am...stop by anytime.

I was working on it tonight and I got no where. I down jetted to a 60 thought it worked well. I then ate dinner came back out and the same thing happened. Sluggish, this time with the 60 it would bog a time bit at full throttle. I am getting the same result if I had the 66 in there..hmmm...

I did put a different manifold on but dont' think it helped...could be a seal...which would suck..

Re: Puch: High Idle, Sluggish at start.

I still think you are overjetted... if it bogged less with the 60 When my Newport had a stock pipe it did the same thing until I downjetted toa 50..... they it took off smooooooth no popping downhill and accellerated smooth right up through full throttle... I have a # 50 and #54 jet if you want to try it for the hell of it... I would... if it is the same engine as mine the stock jet is only a 50 and mine will only run with a 60 with a biturbo and a Hi Per a/f or the black airbox with the plug removed... the 15mm carb is dumping too much fuel into the piston I bet...

Re: Puch: High Idle, Sluggish at start.

Sounds like a plan to me...I will try anything...If I could try your 50 and 54 that would be awesome.

I am going to try a 60 and the high performance tonight before work. If tonight is not good for you, I can definitely meet you sometime this weekend...

Thanks a bunch..

Re: Puch: High Idle, Sluggish at start.


I have yoga class tonight at 7:00 in Central Sq. but I'm free all day so I could drop by a couple of jets and the gasket anytime...

Let me know when you are around and I'll get those jets to you...

I don't think the #60 is gonna do the trick with a stock pipe and a Hi Perf a/f... so if you let me know when you are around I'll drop bring over the other jets and you can try them all at once while you are all smellin like gasoline from the carb lol...

If you want me to drop the parts at your place while you are at work just email me your new address and I'll leave them for you somewhere ...

Re: Puch: High Idle, Sluggish at start.

I will be at home on Saturday working on the 'peds from about 10am on. I will be at the Abbey Lounge tonight from 7:30pm until 1am at the door..so you could definitely stop on by if you have time. I just stand around. If you want to come out Saturday Morning or Mid-day and plug away with me that is fine also. I have a moby to work on and need to change the tubes on another Maxi I have...so it will be workin on peds most of the day.

Well, it is the Biturbo..I have no high performace airfilter..

I have a 64 Jet and a Biturbo right now.. and this morning it was not cutting out but running with very very low power.

I tried it with a 60 and it just bogged and cut the engine out. I can try a 68. I don't think I have a 62 or 66.

I do not have a 58 but have a 56.

Re: Puch: High Idle, Sluggish at start.

I though you were running a stock pipe...

I have a Biturbo on my Newport and the combination that works best for me is a #60 with the plug removed from the back of the airbox it won't run with it in.. it bogs and dies.... but out it comes to life...

Is your plug in or out? The plug is critical!

Re: Puch: High Idle, Sluggish at start.

The plug is out. I had the stock muffler on this week but decided to put the Biturbo back on and try it out again...well. They 60 bogged the engine to cutting out. I have a spark airbox I could drill a hole or two in...so I might try that until I get a good mix...

Re: Puch: High Idle, Sluggish at start.

okay, so heres what i dont get

this bike ran like a machine all of last summer right, untill the end of the summer it started to get slower on the low end

why would jetting/carb/air/muffler ect have anything to do with this, wouldnt the sudden loss of speed, and not being able to fix it with things like cleaning the carb, cleaning the air filter, exhuast port ect. lead you to believe its a problem with something else, because the bike eventually gets up to full speed right? it just takes its sweet time getting there

what about an air leak, either around the manifold, or one of the crank seals, or clutch pads wearing down, blowback caused by worn rings

Re: Puch: High Idle, Sluggish at start.

those Puchs are tough... I'd be surpried if something major just wore out out of the blue... my guess is it's something simple like a clogged exhaust... that's the problem I had with mine...

Re: Puch: High Idle, Sluggish at start.

yeah but he already checked and cleaned the exhuast and tried using the stock pipe again, i swear its gotta be something with the clutch or the main crankshaft seals,

Re: Puch: High Idle, Sluggish at start.

Probably....I rode all night tonight with a 68 jet and a Biturbo. Ran horrible on the low end...but top out at 32 - 33 on the flats. Low end is bad, top end fine. I replaced the cylinder gasket but I still think it is losing compression there....gas leaking out. So I am back to my starting point..

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