E50 acceleration problem

Puch E50 50cc

Stock square port cylinder and head

Bing 1/14/157 on a stock 14mm intake

Atomizer--217

Needle-- one line/band on the second groove

Jet---65

Slide---#24 I think

No vacuum leaks that I can find.

The ignition is all new and all Bosch

The engine starts fine on the first kick and idles very smooth, So on to the problem, Very poor acceleration to the point of having to play with the throttle to get it to mid-range power. Once it gets mid-range it pulls hard and the top end is great but as I said it has little low end power. I know I need to mess with the clutch but that’s down the road for now. The plug NGK BP5HS is a bit lean so maybe up one on the jet. I have looked and been reading to the point that my eyes are starting to bleed.

Any ideas?

Thank You for looking

Re: E50 acceleration problem

roots to wings /

Try a 64 bing oem jet with that setup if you are running stock airbox and pipe. IThats what would have been stock on it. If the 65 is a generic jet, i think it's not right.

Re: E50 acceleration problem

Leave the jet, but raise your needle, move the clip down one more notch. If that doesnt help then maybe move up another jet.

Re: E50 acceleration problem

I forgot to post that it has a Tecno bullet pipe and foam air filter.

Re: E50 acceleration problem

Aside from needing to tune the clutch you might be too lean. Techno pipe and foam filter even on a stock cylinder is gonna need a higher jet than stock 64. My guess would be 68-72 range but you’ll need to see what works best for your setup

Re: E50 acceleration problem

See I had assumed it was still stock. Yeah what mike said about the upjet. Get a range from 66 - 70 and one of those jets will be what you need. I would get a 67, 68, & 69.

Re: E50 acceleration problem

Probably Fred /

Mismatched no low end set up that has Wrong jet, wrong atomizer, wrong filter, no lowend pipe and not tuned clutch,

Use a 222 atomizer in your 14mm bing, around 70-72 jet, metal mesh filter, tecno circuit pipe, get stiff kickstart springs 2-3 turns in from flush,

Maybe until you get a pipe that has more low end change the 217 15mm bing atomizer to the correct 14mm 222 atomizer that comes stock on a 2hp square port cylinder, get rid of the restrictive especially when wet form filter, get a mesh one

And like it or not you have to tune your clutch so you could jet when in the pipe/powerband not before so you won’t have goofy jetting when you’re in the pipe,

To me Low end power is a must on a moped for a quick takeoff to keep cars off your butt so I have no love for bullet or boss pipes on stock cylinders

Re: E50 acceleration problem

roots to wings /

^^this

Re: E50 acceleration problem

I did try the same set up as posted but with a Atomizer—222 ( I don’t remember the jet)and it ran really bad with no top end and acceleration Was about the same. I’m going to a treats bing metal hi flow filter with a fatter jet and the needle up one. It’s wet so no test riding till it’s dry so I’ll post back any results.

Thank You much for the help

Re: E50 acceleration problem

Get a range from 72 down then if you are getting that hi flow filter.

Re: E50 acceleration problem

Now it's wet and too cold to even think of riding.

Re: E50 acceleration problem

Perfect day to start planning things and make a parts order, so when it's nice again you will be all set.

Re: E50 acceleration problem

♣Slew Foot♣ /

The one jet size above would be for cold temps and a 5 is pretty hot. 6 or 7 if cold weather a colder plug works better at WOT.

Re: E50 acceleration problem

I run b7hs in everything. Even non kitted bikes and have had no problems. I havent tuned anything crazy enough to need a b8 or b9.

Re: E50 acceleration problem

Update

Installed Atomizer 222

Jet 71

Needle-- one line/band now on full rich

treats bing metal hi flow filter

It runs but idles very low and will die even with the idle screw all the way in so I need to check timing and will do the clutch once I know the engine is right. I might have to lean the needle one grove.

Re: E50 acceleration problem

roots to wings /

72 clip 2

Re: E50 acceleration problem

I think you may be at the point to start looking at the bing slide mod.

The right jet for top will be so fat at idle, even with the best needle/atomizer.

The slide mod takes away a little material right where the vacuum pulls fuel at idle, allowing the idle adjust screw to actually cause a difference in idle mixture.

Very quick and easy to do.

Re: E50 acceleration problem

I just re-read that thread for fun.

Jeff, you were on there 2 years ago.

Don’t know if you ever got your question about venturi mods answered, but I still think the slide mod is the way to go.

Re: E50 acceleration problem

> Papa _ Wrote:

> -------------------------------------------------------

> I just re-read that thread for fun.

>

> Jeff, you were on there 2 years ago.

>

> Don’t know if you ever got your question about venturi mods answered,

> but I still think the slide mod is the way to go.

I forgot about that. you might know I have two modded slides in the box, i think i need to get closer then drop one in.

Re: E50 acceleration problem

Installed Atomizer 222

Jet 71

Needle-- one line/band now on full lean

treats bing metal hi flow filter

I was playing with the idle screw when it fell out and started to idle right and I went back to the stock (unmodded) slide and went to full lean on the needle . it runs so much better now. oh and I bumped the timing up 2 degrees.

Re: E50 acceleration problem

So where did that put your timing?

Re: E50 acceleration problem

I think it's at 17btdc, I need to recheck tdc before can say for sure.

Re: E50 acceleration problem

Ok it's at 19degrees. It still idles a bit low for me but it works. What should the idle be at?

Re: E50 acceleration problem

After riding and timing again it likes 21degress.

Re: E50 acceleration problem

Awesome. I'll give some timing adjustments a shot after i put a new float in.

Re: E50 acceleration problem

You'll have a mean machine when you're done.

Re: E50 acceleration problem

While talking aboot bings. What is the purpose of the whole in the #51 slide?

Re: E50 acceleration problem

roots to wings /

Search this and you’ll see

Re: E50 acceleration problem

I used a different browser and found the info

Thank You all for the help.

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