port maching

ever since i port matched my case to fit a polini kit. it doesnt haul ass anymore.

ive gone thru my set up over and over.

it works best with a 15 bing 92 jet. and im probably hittin low 30s ( before i used to be boosting to 55 with a 4p )

my 4 petal dellorto set with a 19 pbhg 105 main with a 6p gets around the same speed area.

i havent changed my gearing yet. i keep thinkin that there should be enough power going to my kit to get me there after riding a flat mile.

i think im getting braindead from petrol huffin.

BTW ive had this polini for 2 years and gone thru 3 pistons and 5 rings.

could it be time for a new kit?

it still has good compression. and it seems like it will pull when its on my kickstand but as soon as i get on it. i get nothing. my ported stock cylinder pulls harder than this thing.

i ported accorinding to specifications. i noticed the loss of intensity in my polini after i ported . is there some guidelines to follow to set up after to tune it? b4 i got out and grab a new polini?

Re: port maching

Do you have a picture of the port matching job? It could be that you lost some primary compression by matching up your case, and if you went overboard, it could be bad...

BUT

My money is that you've messed up your timing having split the case to match it to the Polini. Check that first.

Re: port maching

mouthfullagas /

well i got new points should i check for the timing TDC?

Re: port maching

mouthfullagas /

Ok so I jus put on my 65 metrakit on it and still no power! My moped walks instead of runs . Should I put on virgin e50 case and run it ? Cuz I'm quite fed up wit this.

Re: port maching

Yeah...did you split your case to port match?

Cause if you did, then yeah....your timing is way off. If you didn't, then you have a much larger/weirder problem.

Re: port maching

timing made a huge difference in mine after i took it apart the first time. definitely make sure you're advanced and that your points are working right.

Re: port maching

upjet.

timing could be the issue too,.

~SAB AT!

Re: port maching

mouthfullagas /

yea i split the cases to port it.

i upjetted alll the way to a 120 bing jet on there....

i've advanced my timing all the way ( stator plate ). and adjusted the gaps from .14 to the highest it can go without starting

even when i run a more advanced gap. they always tend to end up at the same spot after a days worth of riding. tightened fully! wierd!

why would splitting the case affect timing?

.... would it help to clean it up a lil while the case is enclosed?

Re: port maching

mouthfullagas /

ok so i looked in the wiki section under e50 rebuild. and he only ports the outter part of the case. i took out alot of material from deeper in the case, until it narrows down to the crank. ARGH!! .... thanks to all those who relpied. i got some work to do !

Re: port maching

Let's see some pictures, I still have a hard time believing that is the problem.

Re: port maching

You can replace some of the material you cut out with "quik steel" or "JB weld" putty. Just make sure everything is super clean (use IPA, or acetone on a rag to clean the surface) Be sure it's all cured before you try to run it. If you put in to much putty you can always cut it back out the same way you did the first time.

I'm sure someones going to say "it's a bad idea and that the putty will fall out into your engine", but people have been doing this for years with out problems on much larger displacement 2 strokes, I've even seen people use it to stuff cranks and crank cases; it's cheaper then buying new cases tha's for sure.

Re: port maching

Did you check your timing? It may be retarded. Advance that shit and see if you have power again.

Re: port maching

mouthfullagas /

it was my timing that was the problem! i dont have a woodruff key so im going by a lil sharpie mark on the crank arm and the flywheel!

1221072985_img_0773.jpg

Re: port maching

mouthfullagas /

not proud of my port job but im glad that wasnt the problem! some times it forget all the minor shit that is essential in mopedding...

1221073172_img_0774.jpg

Re: port maching

Hey, since you need some practice setting your timing, why don't you split your case again, go back and add the two new transfer ports for your Polini and you will stop burning up pistons.

It will help cool the top of your piston and give you more oomph. Not optional! I used a hand file for these, you don't have to take away too much material! Good luck!

Re: port maching

2nded

Re: port maching

mouthfullagas /

what a work of art! im gonna hafta step it up no doubt! i got another e50 im building right now and i think im gonna have to add those transfer ports . thanks for all the help!

Re: port maching

Text book Polini right there folks, nice work Phil.

Re: port maching

Just FYI, that was done by Devin Biek of Motion Left Mopeds.

Re: port maching

Now I see why everybody wants Devin to do their port work, that's top notch.

Re: port maching

Here was first attempt at port matching a polini to an e50...

Re: port maching

Mine looks a lot more like yours, but I've had Devin do a case for me, and it's fun to watch him work. And fun to watch him pee in a jug.

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