more lowend, V1 sebring w/ zen pipe

so im in the process of tuning a sebring with the minarelli v1... picked up a zen pipe from treatshq. Lots of great midrange, top end increased a bit and low end increased a little... still very slow off the start and only starts to climb well around 10 mph till about 32-35.. then slowly increased to about 38-40 depending on weather temp.

I can feel that the ped just wants to keep climbing and plug chops show im running slightly rich...

I have a 14 SHA on it, all stock besides the pipe.

A bit confused about what to do... Pretty sure I should switch to a PHBG carb, more tuning options all across the power band.. but its a lot of cash and i want to get it right first. Not going to attach a kit to this moped.

Not really looking to change the sprockets - but I guess I can.

Any help offered is appreciated.. im new to tuning mopeds and am slowly learning the phsyics of it.

Picked up a garelli w/ 20mm pbhg, 70cc polini, homeo6p and slapped on a malossi horn air filter... been tuning that and gaining experience.

But thats about all the experience I have so far.. making sure that i dont seize with that kit :/

The sebring is my everyday runner though, super reliable, starts on the first pedal, amazing with gas (and a huge tank) and just trying to get more umph on the start...

Re: more lowend, V1 sebring w/ zen pipe

Perfekt Timing Angel /

Gearing fo' sho'. What do you have on there now?

They are fairly heavy bikes. You could try opening the intake and exhaust ports..I have not seen the Zen pipe headers up close, so I'm just guessing that it would need to be matched to the cylinder.

38 is pretty good for that bike with only a new exhaust and upjetting. With the gearing, you will have to experiment as you will either lose top end, or lose bottom end depending on what you're going for.

Re: more lowend, V1 sebring w/ zen pipe

Perfekt Timing Angel /

Um, I'm not sure how got stuck in my name....hopefully this fixes it.

Re: more lowend, V1 sebring w/ zen pipe

ill have to check the gearing when i get home ... luckily i think i have some larger and smaller rear ones sitting in my baement.

the header is matched to the cylinder :)

and damn right those are heavy bikes! the thing is impossible to move into the basement and a bitch to get on my porch...

i toss my garelli gran sport around!

thanks for the info - it'll give me a chance to clean up the rear brakes and look over my bearings. ill play around with it

i wonder if ill need a bigger chain?

any suggestions on a good gear ratio? Ill check the rear gear and see if its near 38, no idea what the front gear is... i hear 16-18/38-45 is a good combo

Re: more lowend, V1 sebring w/ zen pipe

Drilling the intake and switching to a 15.15 made a world of difference on my v1 when it was stock.

Re: more lowend, V1 sebring w/ zen pipe

Perfekt Timing Angel /

A 15:15 on my bike, along with a Mamba pipe, stock cylinder-38.9mm, and 11 X 44 gearing had me somewhere in the range of 35 mph before I kitted it. Granted, it was on a lighter bike, but it was/is a hill-eater. Topped out quick, though.

The stock cylinder bore on my Sebring is 40.8mm, and with a Mamba, 15:15, and 9 X 45 gearing tops out somewhere below 40 mph. Not as much as a hill-eater, but not a speed-demon. It's right in the middle (it could use a little finagling).

I have another Sebring, completely unmodded, that has 10 X 44 (I think?). I'm not sure of the bore, smaller than 40.8mm, maybe 38 or 39.something mm. It's a pretty ballzy little machine as well (even with a 200 lbs dude on it). Has very similiar torque, but less up top (tops out about 30 mph).

Re: more lowend, V1 sebring w/ zen pipe

Whats with the weird gearing on your sebring? mine has a 34 tooth sprocket on the rear??? Duh, maybe its the Morini, I guess its gearing is different?

Re: more lowend, V1 sebring w/ zen pipe

Perfekt Timing Angel /

Hmm, dunno. All three bikes were geared low when I got them. It's a Minarelli thing, I guess.

Oh, and Tomtom, most Minarelli v1's are equipped with a 9, 10, 11, 12, or very rarely, a 13 tooth front sprocket. I think the 16/18 dealio you are thinking of is for Puch. Once you know what yer front is, then you can calculate what you would need for your rear.

Sebrings FTW!

Re: more lowend, V1 sebring w/ zen pipe

a 19mm or bigger phbg is straight overkill on a stock minarelli cylinder. if you need more low end for your big heavy sebring gearing is where its at. grab yourself a 9 or 10 front sprocket and swap it out. its almost easier that changing a puch front sprocket. just one little nut!

Re: more lowend, V1 sebring w/ zen pipe

until it flies off.


Re: more lowend, V1 sebring w/ zen pipe

i would gear for torque and port for revs. especially if you're hitting 40 right now, go down a tooth or two, then open up the intake... maybe mill the head.

Re: more lowend, V1 sebring w/ zen pipe

sweet deal, lots of great info.

i found a nice 9 tooth sitting around... so i'll probably slap that on the front.

When it comes to opening the intake and milling the head... could any short explainations or links be given?

I think I'll look at 15:15 pbhg ... i really low the tuning options that carb gives. and the SHA looks like it gets lean randomly...

Re: more lowend, V1 sebring w/ zen pipe

small phbg's are sick! i have a 16mm phbg on my polini kitted v1. make sure you get a phbg intake though...your stock one wont work with that carb. i totally recommend the phbg though...15mm phbg is a world different than a 15mm sha. im curious to see what thatll do to a stock ped.

Re: more lowend, V1 sebring w/ zen pipe

minerelli take well to light porting too!

Re: more lowend, V1 sebring w/ zen pipe

sweet.., ill be getting a 15 phbg sometime in the mail and i'll let you know how it turns out. I have a box of intakes i've been meaning to measure and photograph.. sell it all. im sure i could find something that fits

thanks for the advice again. atleast winter is good for this

Re: more lowend, V1 sebring w/ zen pipe


Wondering how the sebring is turning out.... I have a zen on mine right now, everything else is stock for now, and still waiting for warmer weather to plug chop....

On the few days it gets up into the 40's i upjetted 4 jets and was four stroking and kept backing down until i was only up-jetted by 1. Do you remember how much you up-jetted when you only had the zen on there?

Also let me know how the mods go because they are def in my future when i get the extra $$..

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