Cant get past 25 Mph

Thanks for any help you can provide on this one.

I bought a 2 hp Maxi about 4 years ago... it only went 12 mph when I got it,... now I am up to 25 mph, but cant seem to get past that... What I have done already...

(1) installed a new carb (bing just slightly bigger than stock)

(2) rejetted to a 62 (dont want to go much higher as one of the main reasons I ride is MPG),

(3) put on a bi-turbo,

(4) replaced spark plug,

(5) cleaned the piston shaft,

(6) replaced the head gasket

I am kind of out of ideas and feel like I should be getting up past 25 mph already? In particular I really struggle up hills all sorts.

Any advise? - Thanks.


Re: Cant get past 25 Mph

You need a high flow filter and probably a bigger main jet, but not much I wouldn't think... Have you ever decoked your cylinder and piston crown? Got Type F tranny oil in there? Ever done a plug chop or cleaned your points?

Re: Cant get past 25 Mph

Thanks for the reply Chris....

I have tried running without an air filter, but that did not produce any signifigant effects.

I have not ever decoked the cylinder and piston crown

I have never added tranny oil

Plug chop yes, cleaned points - no.

I will look up how to decok the cylinder and piston crown, add tranny oil and clean points.

Thanks for the tips.


Re: Cant get past 25 Mph

Ben Van Zoest /

How many miles??

Re: Cant get past 25 Mph

About 3000 miles. (I have only put ~300 miles on it since owning it).

Re: Cant get past 25 Mph

De-coke just means clean all the carbon buildup off. The wiki is your friend.

You should try a higher flow air filter, but not ditch it completely. Try making one with some layers of panty hose. Do not worry about increasing the jet size. At this point, you are not going to affect fuel efficiency. And if you run a jet that is too lean, you'll just break your moped.

This article tells you how to clean your points, as well as many other useful things:

Do you know if you have a 1 speed or a 2 speed engine? If the right side of the engine is rectangular and says "PUCH" it's a two speed. If it's sort of roundish and says nothing, it's a one speed. The one speed engine is called the E50, and should have a stamp that says that on the engine somewhere. The two speed is called the ZA50.

As far as hills go, the biturbo is hurting you. After you get your setup tuned correctly, you should get an estoril.

Re: Cant get past 25 Mph

the power is in the points! the main reason why bikes are slower than they should be often is electrical.

electrical, clean or replace the points and advance the timing, regap the points to a hairline fracture (sry i don't have the spec) or just mess with the points some after u clean them.

the high filter isn't really gonna get u faster, its tuning the correct amount of mix to air that will get you more speed and fuel efficency.

also removing the "hocky puck" filter from inside the stock airbox will make it more high flow.

play with jetting as well, get yourself a range of jets from 57-67 and see what jet the bike runs best at.

remember to pick an air filter system and stick with it b4 u start to mess with jetting, otherwise ur changing multiple variables at once and tuning dosen't work well.

Re: Cant get past 25 Mph

Get a high compression head, install without a head gasket.

Adjust the timing, Just experiment with what you get. I first set full advance, and then backed off until it ran the best.

As mentioned before, the biturbo isn't helping.

My setup was basically stock with a HC head, no gasket, leovince pipe, generic carb. It would do 30-32 mph flat out. Hills I would do 25 mph if I had a running start, 15 up from a stop.

Re: Cant get past 25 Mph

If I'm not mistaken the 2hp models aren't supposed to have head gaskets. My maxi luxe high torque didn't.

Re: Cant get past 25 Mph

Thanks for all the tips.... I am going to replace the tranny fluid (not sure why this would make it go faster,... but it is probaby overdue anyway) and clean the points. I'll report back....



Re: Cant get past 25 Mph

well if u have 2 much trany fluid it creates enuf friction on the gears to slow u down if u don't have enuf u will need new gears

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account