Motron sprint +7mph

My motron sprint goes 23-24 mph on a flat road. I would like it to run around 30Mph. It has a minarelli V1 all stock except the carb has a #52 jet instead of a #49. Any suggestions would be appreciated.

Re: Motron sprint +7mph

Have you checked to see if that jetting is correct? Do some plug chops and mess around with your jetting. Also make sure your air filter is clean, and maybe try a less restrictive air filter. Cleaning out your exhaust would also be a good thing to try, as well as checking your piston to see if you have any blow-by going on.

Re: Motron sprint +7mph

Performance exhaust, and upjet. Maybe a bigger intake / carb bore if yours has that really restricted intake.

Re: Motron sprint +7mph

This is what I did to my motron to get it from about 24 mph to 32 mph:

1) bought a used biturbo exhaust. Had someone cut and weld it to fit correctly. Exhaust was 20 bucks

2) derestrict your airfilter

3) upjet to about a 56

Also set your timing right. 32 is about all I could get out of my stock cylinder without porting it.

Re: Motron sprint +7mph

Take the cylinder off then look at my stock cylinder.

Port the main transfers. Big boost.


Re: Motron sprint +7mph

15.15 + estoril pipe got me to 33. Open up the intake, intake port, and exhaust port.

Re: Motron sprint +7mph

ed, what kind of bike is that cylinder on?? That just gave me a great idea for opening up my transfers on my minarelli polini.. Do you have some before pics?

Re: Motron sprint +7mph

That cylinder is a hmmm 20 mph cylinder.:)


Re: Motron sprint +7mph


how fast does your 20mph cylinder go now?

Re: Motron sprint +7mph

I have to up jet to a 56 without doing anything to my intake you exhaust. a nice 30 with alot of pull up hill, both plastic tubes removed.

Re: Motron sprint +7mph


Re: Motron sprint +7mph


my v1 ran exactly like yours, i could not break 24mph most the time it went about 22mph

first i bored out the intake and intake on the cylinder ,smoothed out the exhaust enlarged the case port on the cylinder but nothing like ed. i wasnt sure how much to remove and this was before i saw eds pics.

smoothed out the exhaust pipe but it still only did 24mph more steady now.

then i drill the baffle holes larger

then i installed a #57 jet

then remove the 2 restictor tubes from the airfilter cover

now im am doing 30 mph + !

i was going to get a kit now i dont think i will.

i was going to get a pipe, now i dont think so.

i may get a bigger intake and carb and do some porting on the case . i should just quit while im ahead,it runs sooooo good now.

just do it in the order i listed . i did it out of order and seized the motor 4 or 5 times!

Re: Motron sprint +7mph

Alright ill look a little closer at the carb to see if i find the restricter tubes and such. I was just planning on upjetting to a 56-57 and adding a new pipe, possibly and estoril. Then getting a high flow filter, or i guess removing the restrictor tubes. any advice

Re: Motron sprint +7mph

i was going to get a pipe and filter but now i may wait awhile because it runs so good with the stock stuff.

i like the fact that its not loud because i roll at all hours in the early morning. we have a very quiet neighborhood.all my other peds are loud. too loud

with both restrictors out its little louder when i get on it .but with the airfilter cover off its much louder,

Re: Motron sprint +7mph

What do think would be the best option for me. I'm leaning towards just a pipe and an upjet with a filter

Re: Motron sprint +7mph


give it a try ,that should bring u up to speed, then you can allways do some porting later

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