20 MPH what next (part 2)

Hey everyone! First off, thank you all for your input and advice. It has been super helpful. The old thread was getting kinda long and I have changed so much on the ped that a lot of the advice (although useful for future knowledge) was no longer relevant.

Here is the deal for you that are new to my issues....

I have a 1 HP newprt and a 1 hp maxi. I have put the maxi aside for now and am working on the newport solely. It came with a 12mm carb with 52 jet and 12mm intake and a #2 cylinder. The cylinder had a small metal ring inside of the trapezoid intake port as well as a longer piston skirt which covered up the intake at TDC. It was originally geared at 13 x 45, and would do 20mph and sounded good, and has great compression.

Latest mods are as follows:

I have popped out the restrictor, added a 14.5 mm intake, 15mm bing carb, high compression head, shortened the skirt to fully open the intake, added a bi-turboo exhuast and high flow air filter and changed the gearing to 14 x 38. The 15mm bing came with an 82 jet which we have decided was way too big. I have 66- 72 on order, and they should be here soon to help out with that issue. I currently am running my 12mm bing with a 64 jet and the 14.5mm intake, which is perfect. The 62 was too lean, and the 66 caused 4 stroking.

To make a long story short (too late) My ped still only goes 25 - 26 mph with the current set-up. Shouldn't I be going way faster than that? I have not touched the timing or tried to port anything yet. Thoughts, comments, statements of fact?

Re: 20 MPH what next (part 2)

Is the exhaust port nice and clean?

Re: 20 MPH what next (part 2)

the 66 is four stroking in a 14mm? that is strange.

Re: 20 MPH what next (part 2)

No, the 66 is 4 stroking in a 12mm carb with a 14 intake.

Re: 20 MPH what next (part 2)

Isn't using the larger intake with the smaller carb a bad idea because of pressure reasons? Correct me if I'm wrong, but I think that may have something to do with it.

Re: 20 MPH what next (part 2)

Ok sports fans here we go again. I have jets from 52 - 72 and 82 - 88

15mm carb, 82 jet, no air filter = a little too rich, no power at WOT

15mm carb, 72 jet, no air filter = way too lean

15mm carb, 72 jet, high flow filter = too lean

15mm carb, 72 jet, stock air box with the little white tube yanked out = almost, but it is 4- stroking at WOT

15mm carb, 70 jet, stock air-box = perfect

I have no jets between 72 and 82 but I want to run the high flow filter, since the .... I am thinking 78 maybe. This is more for information than anything else. By the way I was rolling at 28 mph with the 70 and stock air box, will the high flow filter and the bigger jet get me the holy grail of 30 mph? I'll let you know!

Re: 20 MPH what next (part 2)

sounds like you'll be dead on with a 74 or 76/ hiflo. that still seems slow (28) with a pipe. is there anything dragging? when did you repack the bearings (you DID repack the bearings right?) brake. etc?

Re: 20 MPH what next (part 2)

umm... repack the bearings?

Re: 20 MPH what next (part 2)

Well, here is the deal. I can't get the stupid thing to run with the high flow filter no matter how hard I try. I have a full range of jets from 56 - 88 and none of them seem to work! On the stand, the 74 jet with the 15mm bing SCREAMS... like 12,000 rpms. Winds right up, sounds great, looks great, I figure here we go! I sit on it, and the ped won't break 15mph and takes 3 weeks to get there. I have tried a 70, 72, and 76 and 78. None of them run as well on the stand, and even worse with a rider. What gives? I should add that the 70 jet with the stock airbox was a tad lean in the colder weather, but the 72 with the stock box was right on time and got me running at 28-30 mph.

Any ideas on why the high flow air filter won't work or anyone had this problem before? I really think the stock airbox is limiting my potential.

Re: 20 MPH what next (part 2)

Take the air box off put the 82 jet in it run it around and look t the plug, you may need and 84 or 86 with that cold weather up there in new york. Just do some plug chops and make sure that bing isnt leaking air I put RTV around the clamp on mine.

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