Puch Achieve Higher RPM's

Hey, this is mainly aimed towards the 50mph crowd, perferably ones with 65 metras. What are ways to increase my maximum rpm's on my engine.

Right now, I'm getting about to 45-46mph with 18/45 gears. But, being knowlegable on engines in general, I can tell that i can get more rpms outa it. It sounds more of a aaaaaaaaaaaaa instead of the eeeeeeeeeeeeeeee that a higher rpm motor sounds like.

I have a 21mm dellorto and estoril on it. I'm thinking that a more high end pipe would help, but is there anything else you guys do to get more out of you metras?

Thanks

TaylorN.

Re: Puch Achieve Higher RPM's

hpi, race crank, lightened tranny components, cylinder porting, better oil, tranny and gas, umm that should give you a few

Puch Achieve Higher RPM's

Port that shit, then tune your carb a bit better.

Re: Puch Achieve Higher RPM's

I've got a race crank. I'm running $16 a quart oil and premium gas. I'll print out and read jennings part on porting. I'm gonna go play around with my carb a little.

TaylorN.

Re: Puch Achieve Higher RPM's

Adjust your ignition timing. The closer you are to TDC the easier it is for the engine to spin up. Run a colder sparkplug (NGK -B8) Make sure that your intake manifold, and intake port on the cylinder are large enough to flow a 21mm carb. Port match the exhaust flange to the pipe you're using, even if that means welding up a new header.

Re: Puch Achieve Higher RPM's

Yea a different pipe will help. Estorils have a ceiling whereas some others just seem to go forever if you got the horses. Raise bothe exhaust and intake ports with the dremel or if you use more base gaskets be sure to raise the compression ratio. Polini cylinder's exhuast ports open just 1 inch from the top deck

Re: Puch Achieve Higher RPM's

my polini opens more like 3/4 and is ramped. I think you want to lower/widen the intake port on a piston port not raise it right?

Re: Puch Achieve Higher RPM's

wait its all relative to the specific top end, nvm.

Re: Puch Achieve Higher RPM's

I should have said 'intake transfers'

Re: Puch Achieve Higher RPM's

Thanks guys! I'm gonna make up a new intake soon. Right now I have a somewhat crappy constructed exhaust intake. I have some pipe and and weld L that are gonna be perfect. One of my problems is the inside of the intake is pretty rough because I forgot to set my welders voltage down cuz of the thin wall, so I had to fill a hole. haha. About how much would you reccommend raising the exhaust port? Raising it allows the exhaust to get out of the cylinder quicker right? Wouldnt adding a base gasket change that differently because it would raise the exhaust, transfers, and intake up. And like elliot said, wouldn't you want to lower rather than raise the intake?

TaylorN.

Re: Puch Achieve Higher RPM's

oh ok didn't read the intake transfer part till after I posted. BTW, I just got back from doing some speed trials, and I'm up to about 48-49 mph!!!I'm so stoked. I tried it with my hight flow air filter on the carb, and was about 47-48, and then took it off and it increased the speed a little, but I think it also made it richer. yes, richer. If I let up on the throttle from WOT, it picks up. Weird. And I'm running a hella small jet in my opinon. Is a 80 that I filled in and redrilled becuase I didn't have a jet anywhere near the right size when I put the carb on. Then I ordered a 70 72 74 76 78 and the filled jet is smaller than the 70!!! Now I need to order some 60's. argh.

Re: Puch Achieve Higher RPM's

What does your plug look like at WOT?

Re: Puch Achieve Higher RPM's

its pretty black and sooty

Re: Puch Achieve Higher RPM's

Are you four-stroking at WOT? Because that would explain why you think the sound of the engine is telling you it can do more RPMs.

Re: Puch Achieve Higher RPM's

When I had the air filter on, it wasn't 4 stroking, if it was it was so minimal that I didn't notice. then when I pulled the air filter off, it started 4 stroking and if i let up on the throttle a little, it picked up speed but it still sounded like the engine could go more. Lets say you unwrapped the throttle grip and made it flat. Lets say it was 2 inches long. The 4 stroking is only happening in the last 1/4 to 1/8th of an inch. pretty minimal.

Looks like I need to get a tiny tach. anyone got one they want to sell?

thanks for your guys help.

taylor

Re: Puch Achieve Higher RPM's

taking your air filter off will most definitely make you more lean. ie more air going into your carb since it isn't restricted from the filter.

Re: Puch Achieve Higher RPM's

It shouldn't 4 stroke when you take the air filter off, if anything that should fix the problem. 4 stroking is when you get too much gas in your air/fuel mix. Removing the air filter gives you more air, not more gas. Sounds like youre running lean.

Re: Puch Achieve Higher RPM's

yeah be careful dude, make sure it's four stroking that you're hearing

Re: Puch Achieve Higher RPM's

Yeah I know taking off the filter makes it more lean. The feeling I was getting definatly felt like 4 stroking. But when I pulled my plug, you guessed it, pretty white with a touch of brown. yikes! No harm though, but my filter back on and now it is running perfect.

Re: Puch Achieve Higher RPM's

4 stroking is almost always even sounding. you are probably detonating, which will sound more random. theres zero reason for your motor to be doing what you think its doing unless you got some really funky cable action going on

Re: Puch Achieve Higher RPM's

I'm running into this EXACT same thing. I cant get into the last 7/8ths of the throttle.

I have a Minarelli v1 with a BRN 76cc kit, 24mm Mikuni, Minarelli Blaster exhuast, points, matched everything, 190 degrees of exhaust and a gigantic intake port. I've played with jetting and timing repeatedly with little change.

My intake port is very high though. the top of the intake port is as high as it can go without hitting the ring ends, and the bottom is almost stock. But the thing super wide.

The exhaust is also super wide, and bridged so its wider than a normal exhaust port.

I just checked and found micro leaks in the exhaust port cause its a spring exhaust. I'm hoping that when i just fixed it, it solves this throttle issue. We'll see when i get a chance to go out and run it.

Re: Puch Achieve Higher RPM's

Oh crap this is like 2 years old haha

Re: Puch Achieve Higher RPM's

#CrazyWayne™ rocks. #CrazyWayne /

LOL

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