Jog-Mania

[Lucass2T]

When you need to downjet id say mixture flow is less than before...

According to my logic when the engine needs less fuel thats due to less air getting into the engine. So then there must be a loss of flow.

Less air+fuel in the engine is less power.

[tsimi]

So you mean I might have an air leak after all?

When I reach current max rpm (7200) It kinda sounds like there is a limiter preventing the Scooter from reving higher.
I don't know how much impact the reed block currently has on the carb setup.
Just in case I ordered a new gasket for the stock reed block.



Found this:

If you change anything in the engine that changes the way air/fuel flows through the engine you will most likely need to rejet for maximum performance.

However most reed valves will need to be jetted leaner than stock.

True or not I don't know but that kinda makes sense now in my current situation.

[spaz12]

Have you made a leak down tester yet Tsimi?

Even if I don't split the cases, whenever I mess with the intake I do a leak down on my motors because it only takes a few minutes and this way I know my parts have a good seal.

I can't call it if you have a leak or not, but if it's being finicky while trying to tune it then you could have one. Right now I'm thinking that you just haven't gotten the tune down, but that you'll get it.

If you have a leak down tester then you should test it though.

[tsimi]

Never done a leak test. Never build a leak tester.
First I want to try to adjust the jets and if I really should have trouble tuning the carb I might build a tester.

[oldgeek]

Jan 31, 2016 6:57:02 GMT -5 tsimi said:

Never done a leak test. Never build a leak tester.
First I want to try to adjust the jets and if I really should have trouble tuning the carb I might build a tester.

You need to take care of air leaks FIRST if any. I understand though, I am very resistant to doing a leak down test for some reason LoL!

I know I say this a lot on here but an open air filter can be VERY difficult to tune. For me it often causes problems like you are describing. Early on in one of my build threads I was going nuts trying to tune a PHBG with an open filter, nothing was making sense. Brent suggested a stock airbox, and I finally listened. Well to make a long story short the stock style airbox worked, and eventually I was even able to put the open filter back on.

One of my strategies is, if I am having tuning issues with using an open air filter, I temporarily rig a stock style air box, and get it in tune just to prove to myself it can be done. Then I go back to the filter of choice and re-tune. Whatever works!

[oldgeek]

Also what slide and needle did you end up with?

[tsimi]

oldgeek

I don't think that I have an air leak. I used Motoseal when installing the reed block.
I also use the stock airbox and I just changed the sponge inside that airbox.
I don't know yet if the issues I have are due to a new reed block or just the AU parts or entirely something else. I always thought if I indeed should have an air leak wouldn't I run rather lean then rich? Well, I am no expert when it comes to these kinda things.

Needle is a W9
Slider is a 30

40 was not in stock and I got a spare W7 needle if necessary I just don't know what the difference is between a W9 and W7.

[oldgeek]

I am not an expert either so take what I say for what it is.

I highly doubt the new reeds are causing any issues at all.

The 30 slide is likely too rich for your setup, you really need a 40. You should try the 50 you have, or you could try to find a 40 somewhere. As the great PHBG carb guru Corrosion has taught me, you could also use a file to shape your 30 into any size in between a 30 and a 50. I think you will end up needing a 40 something slide.

I also continuously refer to this chart when tuning it helps me remember what I am trying to accomplish.

Learn it, live it, love it!

[tsimi]

Thanks oldgeek

Just read in a topic that a guy had AN stuff inside and swapped to AU stuff and that it needs to run lot leaner then it did with the AN stuff.
Brent always says first tune the main jet at WOT and then check the rest, that of course if I can get up to WOT first.

I am stuck with a 30 slide for now but will try to get a 40 and 50 once I can get the shipping issue sorted.

In that topic mentioned above the guy used to run with a 95-98 on the AN stuff and went down to 88-92 on the AU setup.
The needle might also need adjusting or even swap to W7.

I have to forget what I had previously and start with a fresh mind again.

[tsimi]

Interesting post by corrosion.

[oldgeek]

Busted! Now you know where I got my info! I told you he was the PHBG guru

[90GTVert]

When you need to get more in depth than the typical jet swaps and position changes, it's not a bad idea to check out the DellOrto Tuning Manual. Aside from explaining various circuits, it has charts that will show you needle specs at the end.

www.49ccscoot.com/manuals/DellOrto_Info_And_Tuning_Manual.pdf

[tsimi]

Hey spaz12 look

Here and here

[spaz12]

Feb 3, 2016 23:06:48 GMT -5 tsimi said:

Hey spaz12 look

Here and here

I really like those Mio's and what people do to them. I just wish they were 2 strokes. 

[tsimi]

Even though my #40 carb slider hasn't arrived yet I went out in this cold weather and did some carb tuning.
Reverted CVT to complete stock. Big reed block with glass fiber reeds still installed.

First setting;

Atomizer: AU262
Slider: #30
Needle: W9 (2nd from top)
Pilot Jet: #38
Main Jet: #92

With this setup finally the sputtering at WOT was gone but still not very crisp and not so good response.
0-1/4 was as expected sputtering and rich.
Max rpm was: 8000-8200rpm max. speed 61km/h

2nd setup;

Atomizer: AU262
Slider: #30
Needle: W9 (2nd from top)
Pilot Jet: #38
Main Jet: #90

Very nice acceleration and good throttle response. Still 0-1/4, sputtering and rich, Pilot 38 is too large.
Max rpm was: 8400rpm max. speed 63km/h
Spark plug was perfect. Nice color so Main Jet tuning was done for now.
This was the best WOT result thus far so I thought I concentrate on the Pilot Jet to get rid of the sputtering at low end.
Swapped in the Pilot Jet #35 and went for a ride.
As I thought sputtering is gone and acceleration is good and crisp. Problem was now the Main Jet #90 was too lean. At WOT I could hear the lean condition, metallic sound. CHT was still OK though but I don't want to challenge anything here so went back and put in the Main Jet #92.
Now I am not lean anymore and low end is strong and crisp but I think the 92 Main Jet is a bit rich. Max rpm. didn't drop much maybe 100-200rpms only but it takes longer to get to top speed then with the 35/90 setting.

This is how far I went today. I also didn't really fine tune the mixture screw yet.
What I need to try is a 35/90 setting and fine tune it with the mixture screw.
And also a 37/90 setting would be interesting.

As soon the #40 slider arrives I can try corrosions recommended setting which is;

Atomizer: AU262
Slider: #40-45
Needle: W7 (2nd from top)
Pilot Jet: #42
Main Jet: #90-92

It feels good to be back in a somewhat drivable state. Monday my red Racing CDI should arrive and that should give me another small boost.