Acceleration and bogging down

I've posted a few times now with some problems with my puch maxi 2hp 1977.

Anyways, the update...

Spark plug is perfect

Jet is proper size (after plug chopping)

Electrical system is perfect (i'm an electrical engineer so that was the first thing i knew to fix)

However, I still have the same problem. I cannot accelerate very fast and hills KILL me. I ride with a few people with 1.5 and 1hp puch (no mods), and everyone leaves me in the dust. I would expect that a 2hp would last least keep up.

Any ideas for me to check on my ped to figure out exactly whats wrong with this ped? The only thing I'm not sure about is the throttle cable, how do I check to see if this is working properly?

Re: Acceleration and bogging down

if you pull off the air filter, look in the carb, and pull back the throttle grip, if the slide is all the way up, you're good. if not, adjust it

Re: Acceleration and bogging down

it looks like it's completely up - i don't think that's a problem.

Any other ideas? Why can't I get all the power I realllly have?

Re: Acceleration and bogging down

Some thoughts:

When you say the electrical system is perfect, are you including timing? If everything is working, but that big blue spark comes at the wrong time, it'll really hurt performance.

Make sure the air filter is clean. Probably so, since the plug chop came out OK, but ckeck anyway.

The exhaust system may be clogged, which doesn't let the engine breathe. If the exhaust can't get out, the air/fuel can't get in. We're talking muffler, baffle, pipe, exhaust port. All get clogged after a while.

Does your engine have a reed valve? I don't think so, but if it does, that could be faulty.

Re: Acceleration and bogging down

what size is your carb and intake? if it's 12 like mine, 25 will be your top speed possible

Re: Acceleration and bogging down

Ben Van Zoest /

Since you didn't state the mileage and/or previous abuse, the engine is somehow losing crankcase vacuum or has piston/ring by-blow, do this for vacuum, remove flywheel cover, sparkplug and carburator, put a pencil in the plug hole turn the flywheel until you feel that the piston is all the way back, stop, put your thumb on the intake manifold and move the piston out, you should feel a steady vac pull till TDC. If not find the cause, seals, cylinder/head mating surfaces etc.

For compression the proceedure is the same but cover the sparkplug hole instead, at least this will verify proper compression and iliminate by-blow. Maybe someone can elabriate on this if you don't have a compression gauge.

Re: Acceleration and bogging down

I am not sure about timing.

The air filter is brand new along with a new biturbo. That shouldn't be the problem. The jet is already good with the new stuff on it.

no reed value

Re: Acceleration and bogging down

milage is about 2200

i'm a second owner, so i really don't know about the abuse it's received. It's been kept indoors the past few years.

I need to figure out how to check the pressure. What you said makes sense, and I will try this tomorrow morning sometime. As for compression, I do not have a compression gauge.

thanks for all the help so far!

Re: Acceleration and bogging down

🇮🇹💦 Of the Loin /

sprocket sizes?

Re: Acceleration and bogging down

Ben Van Zoest /

Considering the mileage and it 'sat' for years I would suspect insuffient fuel delivery. Disregard airfilter or muffler, compression/vacuum problems unless the previous owner failed on maintenance. Combustion is designed as 50 parts air to 1 part combustion fume the air part not so critical.

Remove and replace the fuel line but don't hook up to the carb yet drain the tank dry, the tank may have or probally does have crude on the bottom you want to wash that out first. Than refill w/ 2C oil and 92 octain mix because this is a HC engine.

Another issue is the Puch poorly made HV cable, the metal cap one get rid off it and replace it w/ any solid US made modern lawn mower cable.

Re: Acceleration and bogging down

I have replaced the entire fuel line and added an extra filter. I also cleaned out the tank and removed any rust.

What is an HV cable?

Re: Acceleration and bogging down

I have a 15 in the front, but and a 25 or 26 in the back?

I have a 14 on hand. But my top speed is only 26-28 on a flat surface. So i really don't want to back down one size.

Re: Acceleration and bogging down

Ben Van Zoest /

Well it seems you're on top of things, Oh HV is the sparkplug cable. Rider weight matters a lot so does tire pressure.

Re: Acceleration and bogging down

Ben Van Zoest /

Speed is about right for a ped like this.

Re: Acceleration and bogging down

haha havent thought about tire pressure.

i'm 170, so i don't think that's the prob

i'll check the tires

Re: Acceleration and bogging down

even with a high flow filter and biturbo?

I'm more worried about the acceleration...

hmm, something i just thought about...is it normal for your muffler to turn red/brownish where it conencts to the head?

Re: Acceleration and bogging down

Ben Van Zoest /

The much acclaimed high flow filter biturbo hoax proves very little to me besides making someone rich. Fine tuning and perfect carburation of these tiny engines enriches max performance. Although I'm going to drill some holes in my car airfilter housing maybe it will go faster.

Somewhere a tiny leak of oily exhaust discolors the pipe.

If it's the exhaust conn. you could use a copper/asbest compression gasket, hard to get in the US.

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